diff options
Diffstat (limited to 'kernel')
113 files changed, 16267 insertions, 3848 deletions
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz index 526128a..94fabd5 100644 --- a/kernel/Kconfig.hz +++ b/kernel/Kconfig.hz @@ -55,4 +55,4 @@ config HZ default 1000 if HZ_1000 config SCHED_HRTICK - def_bool HIGH_RES_TIMERS && X86 + def_bool HIGH_RES_TIMERS && (!SMP || USE_GENERIC_SMP_HELPERS) diff --git a/kernel/Makefile b/kernel/Makefile index 1c9938a..4e1d7df 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -2,8 +2,8 @@ # Makefile for the linux kernel. # -obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ - exit.o itimer.o time.o softirq.o resource.o \ +obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ + cpu.o exit.o itimer.o time.o softirq.o resource.o \ sysctl.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o \ rcupdate.o extable.o params.o posix-timers.o \ @@ -11,6 +11,20 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ notifier.o ksysfs.o pm_qos_params.o sched_clock.o +CFLAGS_REMOVE_sched.o = -mno-spe + +ifdef CONFIG_FTRACE +# Do not trace debug files and internal ftrace files +CFLAGS_REMOVE_lockdep.o = -pg +CFLAGS_REMOVE_lockdep_proc.o = -pg +CFLAGS_REMOVE_mutex-debug.o = -pg +CFLAGS_REMOVE_rtmutex-debug.o = -pg +CFLAGS_REMOVE_cgroup-debug.o = -pg +CFLAGS_REMOVE_sched_clock.o = -pg +CFLAGS_REMOVE_sched.o = -mno-spe -pg +endif + +obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ @@ -27,7 +41,8 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o -obj-$(CONFIG_SMP) += cpu.o spinlock.o +obj-$(CONFIG_USE_GENERIC_SMP_HELPERS) += smp.o +obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_UID16) += uid16.o @@ -69,6 +84,10 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_LATENCYTOP) += latencytop.o +obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o +obj-$(CONFIG_FTRACE) += trace/ +obj-$(CONFIG_TRACING) += trace/ +obj-$(CONFIG_SMP) += sched_cpupri.o ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is diff --git a/kernel/acct.c b/kernel/acct.c index 91e1cfd..f6006a6 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -75,37 +75,39 @@ int acct_parm[3] = {4, 2, 30}; /* * External references and all of the globals. */ -static void do_acct_process(struct pid_namespace *ns, struct file *); +static void do_acct_process(struct bsd_acct_struct *acct, + struct pid_namespace *ns, struct file *); /* * This structure is used so that all the data protected by lock * can be placed in the same cache line as the lock. This primes * the cache line to have the data after getting the lock. */ -struct acct_glbs { - spinlock_t lock; +struct bsd_acct_struct { volatile int active; volatile int needcheck; struct file *file; struct pid_namespace *ns; struct timer_list timer; + struct list_head list; }; -static struct acct_glbs acct_globals __cacheline_aligned = - {__SPIN_LOCK_UNLOCKED(acct_globals.lock)}; +static DEFINE_SPINLOCK(acct_lock); +static LIST_HEAD(acct_list); /* * Called whenever the timer says to check the free space. */ -static void acct_timeout(unsigned long unused) +static void acct_timeout(unsigned long x) { - acct_globals.needcheck = 1; + struct bsd_acct_struct *acct = (struct bsd_acct_struct *)x; + acct->needcheck = 1; } /* * Check the amount of free space and suspend/resume accordingly. */ -static int check_free_space(struct file *file) +static int check_free_space(struct bsd_acct_struct *acct, struct file *file) { struct kstatfs sbuf; int res; @@ -113,11 +115,11 @@ static int check_free_space(struct file *file) sector_t resume; sector_t suspend; - spin_lock(&acct_globals.lock); - res = acct_globals.active; - if (!file || !acct_globals.needcheck) + spin_lock(&acct_lock); + res = acct->active; + if (!file || !acct->needcheck) goto out; - spin_unlock(&acct_globals.lock); + spin_unlock(&acct_lock); /* May block */ if (vfs_statfs(file->f_path.dentry, &sbuf)) @@ -136,35 +138,35 @@ static int check_free_space(struct file *file) act = 0; /* - * If some joker switched acct_globals.file under us we'ld better be + * If some joker switched acct->file under us we'ld better be * silent and _not_ touch anything. */ - spin_lock(&acct_globals.lock); - if (file != acct_globals.file) { + spin_lock(&acct_lock); + if (file != acct->file) { if (act) res = act>0; goto out; } - if (acct_globals.active) { + if (acct->active) { if (act < 0) { - acct_globals.active = 0; + acct->active = 0; printk(KERN_INFO "Process accounting paused\n"); } } else { if (act > 0) { - acct_globals.active = 1; + acct->active = 1; printk(KERN_INFO "Process accounting resumed\n"); } } - del_timer(&acct_globals.timer); - acct_globals.needcheck = 0; - acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ; - add_timer(&acct_globals.timer); - res = acct_globals.active; + del_timer(&acct->timer); + acct->needcheck = 0; + acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ; + add_timer(&acct->timer); + res = acct->active; out: - spin_unlock(&acct_globals.lock); + spin_unlock(&acct_lock); return res; } @@ -172,39 +174,41 @@ out: * Close the old accounting file (if currently open) and then replace * it with file (if non-NULL). * - * NOTE: acct_globals.lock MUST be held on entry and exit. + * NOTE: acct_lock MUST be held on entry and exit. */ -static void acct_file_reopen(struct file *file) +static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file, + struct pid_namespace *ns) { struct file *old_acct = NULL; struct pid_namespace *old_ns = NULL; - if (acct_globals.file) { - old_acct = acct_globals.file; - old_ns = acct_globals.ns; - del_timer(&acct_globals.timer); - acct_globals.active = 0; - acct_globals.needcheck = 0; - acct_globals.file = NULL; + if (acct->file) { + old_acct = acct->file; + old_ns = acct->ns; + del_timer(&acct->timer); + acct->active = 0; + acct->needcheck = 0; + acct->file = NULL; + acct->ns = NULL; + list_del(&acct->list); } if (file) { - acct_globals.file = file; - acct_globals.ns = get_pid_ns(task_active_pid_ns(current)); - acct_globals.needcheck = 0; - acct_globals.active = 1; + acct->file = file; + acct->ns = ns; + acct->needcheck = 0; + acct->active = 1; + list_add(&acct->list, &acct_list); /* It's been deleted if it was used before so this is safe */ - init_timer(&acct_globals.timer); - acct_globals.timer.function = acct_timeout; - acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ; - add_timer(&acct_globals.timer); + setup_timer(&acct->timer, acct_timeout, (unsigned long)acct); + acct->timer.expires = jiffies + ACCT_TIMEOUT*HZ; + add_timer(&acct->timer); } if (old_acct) { mnt_unpin(old_acct->f_path.mnt); - spin_unlock(&acct_globals.lock); - do_acct_process(old_ns, old_acct); + spin_unlock(&acct_lock); + do_acct_process(acct, old_ns, old_acct); filp_close(old_acct, NULL); - put_pid_ns(old_ns); - spin_lock(&acct_globals.lock); + spin_lock(&acct_lock); } } @@ -212,6 +216,8 @@ static int acct_on(char *name) { struct file *file; int error; + struct pid_namespace *ns; + struct bsd_acct_struct *acct = NULL; /* Difference from BSD - they don't do O_APPEND */ file = filp_open(name, O_WRONLY|O_APPEND|O_LARGEFILE, 0); @@ -228,18 +234,34 @@ static int acct_on(char *name) return -EIO; } + ns = task_active_pid_ns(current); + if (ns->bacct == NULL) { + acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL); + if (acct == NULL) { + filp_close(file, NULL); + return -ENOMEM; + } + } + error = security_acct(file); if (error) { + kfree(acct); filp_close(file, NULL); return error; } - spin_lock(&acct_globals.lock); + spin_lock(&acct_lock); + if (ns->bacct == NULL) { + ns->bacct = acct; + acct = NULL; + } + mnt_pin(file->f_path.mnt); - acct_file_reopen(file); - spin_unlock(&acct_globals.lock); + acct_file_reopen(ns->bacct, file, ns); + spin_unlock(&acct_lock); mntput(file->f_path.mnt); /* it's pinned, now give up active reference */ + kfree(acct); return 0; } @@ -269,11 +291,17 @@ asmlinkage long sys_acct(const char __user *name) error = acct_on(tmp); putname(tmp); } else { + struct bsd_acct_struct *acct; + + acct = task_active_pid_ns(current)->bacct; + if (acct == NULL) + return 0; + error = security_acct(NULL); if (!error) { - spin_lock(&acct_globals.lock); - acct_file_reopen(NULL); - spin_unlock(&acct_globals.lock); + spin_lock(&acct_lock); + acct_file_reopen(acct, NULL, NULL); + spin_unlock(&acct_lock); } } return error; @@ -288,10 +316,16 @@ asmlinkage long sys_acct(const char __user *name) */ void acct_auto_close_mnt(struct vfsmount *m) { - spin_lock(&acct_globals.lock); - if (acct_globals.file && acct_globals.file->f_path.mnt == m) - acct_file_reopen(NULL); - spin_unlock(&acct_globals.lock); + struct bsd_acct_struct *acct; + + spin_lock(&acct_lock); +restart: + list_for_each_entry(acct, &acct_list, list) + if (acct->file && acct->file->f_path.mnt == m) { + acct_file_reopen(acct, NULL, NULL); + goto restart; + } + spin_unlock(&acct_lock); } /** @@ -303,12 +337,31 @@ void acct_auto_close_mnt(struct vfsmount *m) */ void acct_auto_close(struct super_block *sb) { - spin_lock(&acct_globals.lock); - if (acct_globals.file && - acct_globals.file->f_path.mnt->mnt_sb == sb) { - acct_file_reopen(NULL); + struct bsd_acct_struct *acct; + + spin_lock(&acct_lock); +restart: + list_for_each_entry(acct, &acct_list, list) + if (acct->file && acct->file->f_path.mnt->mnt_sb == sb) { + acct_file_reopen(acct, NULL, NULL); + goto restart; + } + spin_unlock(&acct_lock); +} + +void acct_exit_ns(struct pid_namespace *ns) +{ + struct bsd_acct_struct *acct; + + spin_lock(&acct_lock); + acct = ns->bacct; + if (acct != NULL) { + if (acct->file != NULL) + acct_file_reopen(acct, NULL, NULL); + + kfree(acct); } - spin_unlock(&acct_globals.lock); + spin_unlock(&acct_lock); } /* @@ -425,7 +478,8 @@ static u32 encode_float(u64 value) /* * do_acct_process does all actual work. Caller holds the reference to file. */ -static void do_acct_process(struct pid_namespace *ns, struct file *file) +static void do_acct_process(struct bsd_acct_struct *acct, + struct pid_namespace *ns, struct file *file) { struct pacct_struct *pacct = ¤t->signal->pacct; acct_t ac; @@ -440,7 +494,7 @@ static void do_acct_process(struct pid_namespace *ns, struct file *file) * First check to see if there is enough free_space to continue * the process accounting system. */ - if (!check_free_space(file)) + if (!check_free_space(acct, file)) return; /* @@ -494,7 +548,7 @@ static void do_acct_process(struct pid_namespace *ns, struct file *file) #endif spin_lock_irq(¤t->sighand->siglock); - tty = current->signal->tty; + tty = current->signal->tty; /* Safe as we hold the siglock */ ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); @@ -577,34 +631,46 @@ void acct_collect(long exitcode, int group_dead) spin_unlock_irq(¤t->sighand->siglock); } -/** - * acct_process - now just a wrapper around do_acct_process - * @exitcode: task exit code - * - * handles process accounting for an exiting task - */ -void acct_process(void) +static void acct_process_in_ns(struct pid_namespace *ns) { struct file *file = NULL; - struct pid_namespace *ns; + struct bsd_acct_struct *acct; + acct = ns->bacct; /* * accelerate the common fastpath: */ - if (!acct_globals.file) + if (!acct || !acct->file) return; - spin_lock(&acct_globals.lock); - file = acct_globals.file; + spin_lock(&acct_lock); + file = acct->file; if (unlikely(!file)) { - spin_unlock(&acct_globals.lock); + spin_unlock(&acct_lock); return; } get_file(file); - ns = get_pid_ns(acct_globals.ns); - spin_unlock(&acct_globals.lock); + spin_unlock(&acct_lock); - do_acct_process(ns, file); + do_acct_process(acct, ns, file); fput(file); - put_pid_ns(ns); +} + +/** + * acct_process - now just a wrapper around acct_process_in_ns, + * which in turn is a wrapper around do_acct_process. + * + * handles process accounting for an exiting task + */ +void acct_process(void) +{ + struct pid_namespace *ns; + + /* + * This loop is safe lockless, since current is still + * alive and holds its namespace, which in turn holds + * its parent. + */ + for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) + acct_process_in_ns(ns); } diff --git a/kernel/audit.c b/kernel/audit.c index e8692a5..4414e93 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -707,12 +707,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (status_get->mask & AUDIT_STATUS_ENABLED) { err = audit_set_enabled(status_get->enabled, loginuid, sessionid, sid); - if (err < 0) return err; + if (err < 0) + return err; } if (status_get->mask & AUDIT_STATUS_FAILURE) { err = audit_set_failure(status_get->failure, loginuid, sessionid, sid); - if (err < 0) return err; + if (err < 0) + return err; } if (status_get->mask & AUDIT_STATUS_PID) { int new_pid = status_get->pid; @@ -725,9 +727,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_pid = new_pid; audit_nlk_pid = NETLINK_CB(skb).pid; } - if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) + if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { err = audit_set_rate_limit(status_get->rate_limit, loginuid, sessionid, sid); + if (err < 0) + return err; + } if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) err = audit_set_backlog_limit(status_get->backlog_limit, loginuid, sessionid, sid); @@ -738,7 +743,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (!audit_enabled && msg_type != AUDIT_USER_AVC) return 0; - err = audit_filter_user(&NETLINK_CB(skb), msg_type); + err = audit_filter_user(&NETLINK_CB(skb)); if (err == 1) { err = 0; if (msg_type == AUDIT_USER_TTY) { @@ -779,7 +784,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } /* fallthrough */ case AUDIT_LIST: - err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, + err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, uid, seq, data, nlmsg_len(nlh), loginuid, sessionid, sid); break; @@ -798,7 +803,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } /* fallthrough */ case AUDIT_LIST_RULES: - err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, + err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, uid, seq, data, nlmsg_len(nlh), loginuid, sessionid, sid); break; @@ -1366,7 +1371,7 @@ int audit_string_contains_control(const char *string, size_t len) { const unsigned char *p; for (p = string; p < (const unsigned char *)string + len && *p; p++) { - if (*p == '"' || *p < 0x21 || *p > 0x7f) + if (*p == '"' || *p < 0x21 || *p > 0x7e) return 1; } return 0; diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 0e0bd27e..b7d354e 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1022,8 +1022,11 @@ static void audit_update_watch(struct audit_parent *parent, struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); + audit_log_format(ab, "auid=%u ses=%u", + audit_get_loginuid(current), + audit_get_sessionid(current)); audit_log_format(ab, - "op=updated rules specifying path="); + " op=updated rules specifying path="); audit_log_untrustedstring(ab, owatch->path); audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino); @@ -1058,7 +1061,10 @@ static void audit_remove_parent_watches(struct audit_parent *parent) struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - audit_log_format(ab, "op=remove rule path="); + audit_log_format(ab, "auid=%u ses=%u", + audit_get_loginuid(current), + audit_get_sessionid(current)); + audit_log_format(ab, " op=remove rule path="); audit_log_untrustedstring(ab, w->path); if (r->filterkey) { audit_log_format(ab, " key="); @@ -1544,6 +1550,7 @@ static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid, * @data: payload data * @datasz: size of payload data * @loginuid: loginuid of sender + * @sessionid: sessionid for netlink audit message * @sid: SE Linux Security ID of sender */ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, @@ -1720,7 +1727,7 @@ static int audit_filter_user_rules(struct netlink_skb_parms *cb, return 1; } -int audit_filter_user(struct netlink_skb_parms *cb, int type) +int audit_filter_user(struct netlink_skb_parms *cb) { enum audit_state state = AUDIT_DISABLED; struct audit_entry *e; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index c10e7aa..cf5bc2f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -243,7 +243,11 @@ static inline int open_arg(int flags, int mask) static int audit_match_perm(struct audit_context *ctx, int mask) { - unsigned n = ctx->major; + unsigned n; + if (unlikely(!ctx)) + return 0; + n = ctx->major; + switch (audit_classify_syscall(ctx->arch, n)) { case 0: /* native */ if ((mask & AUDIT_PERM_WRITE) && @@ -284,6 +288,10 @@ static int audit_match_filetype(struct audit_context *ctx, int which) { unsigned index = which & ~S_IFMT; mode_t mode = which & S_IFMT; + + if (unlikely(!ctx)) + return 0; + if (index >= ctx->name_count) return 0; if (ctx->names[index].ino == -1) @@ -610,7 +618,7 @@ static int audit_filter_rules(struct task_struct *tsk, if (!result) return 0; } - if (rule->filterkey) + if (rule->filterkey && ctx) ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); switch (rule->action) { case AUDIT_NEVER: *state = AUDIT_DISABLED; break; @@ -1196,13 +1204,13 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", context->return_code); - mutex_lock(&tty_mutex); - read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) tty = tsk->signal->tty->name; else tty = "(none)"; - read_unlock(&tasklist_lock); + spin_unlock_irq(&tsk->sighand->siglock); + audit_log_format(ab, " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" " ppid=%d pid=%d auid=%u uid=%u gid=%u" @@ -1222,7 +1230,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts context->egid, context->sgid, context->fsgid, tty, tsk->sessionid); - mutex_unlock(&tty_mutex); audit_log_task_info(ab, tsk); if (context->filterkey) { @@ -1476,7 +1483,8 @@ void audit_syscall_entry(int arch, int major, struct audit_context *context = tsk->audit_context; enum audit_state state; - BUG_ON(!context); + if (unlikely(!context)) + return; /* * This happens only on certain architectures that make system @@ -2374,7 +2382,7 @@ int __audit_signal_info(int sig, struct task_struct *t) struct audit_context *ctx = tsk->audit_context; if (audit_pid && t->tgid == audit_pid) { - if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) { + if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) { audit_sig_pid = tsk->pid; if (tsk->loginuid != -1) audit_sig_uid = tsk->loginuid; diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c index d1a7605..a5e026b 100644 --- a/kernel/backtracetest.c +++ b/kernel/backtracetest.c @@ -10,30 +10,73 @@ * of the License. */ +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/interrupt.h> #include <linux/module.h> #include <linux/sched.h> -#include <linux/delay.h> +#include <linux/stacktrace.h> + +static void backtrace_test_normal(void) +{ + printk("Testing a backtrace from process context.\n"); + printk("The following trace is a kernel self test and not a bug!\n"); -static struct timer_list backtrace_timer; + dump_stack(); +} -static void backtrace_test_timer(unsigned long data) +static DECLARE_COMPLETION(backtrace_work); + +static void backtrace_test_irq_callback(unsigned long data) +{ + dump_stack(); + complete(&backtrace_work); +} + +static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0); + +static void backtrace_test_irq(void) { printk("Testing a backtrace from irq context.\n"); printk("The following trace is a kernel self test and not a bug!\n"); - dump_stack(); + + init_completion(&backtrace_work); + tasklet_schedule(&backtrace_tasklet); + wait_for_completion(&backtrace_work); +} + +#ifdef CONFIG_STACKTRACE +static void backtrace_test_saved(void) +{ + struct stack_trace trace; + unsigned long entries[8]; + + printk("Testing a saved backtrace.\n"); + printk("The following trace is a kernel self test and not a bug!\n"); + + trace.nr_entries = 0; + trace.max_entries = ARRAY_SIZE(entries); + trace.entries = entries; + trace.skip = 0; + + save_stack_trace(&trace); + print_stack_trace(&trace, 0); +} +#else +static void backtrace_test_saved(void) +{ + printk("Saved backtrace test skipped.\n"); } +#endif + static int backtrace_regression_test(void) { printk("====[ backtrace testing ]===========\n"); - printk("Testing a backtrace from process context.\n"); - printk("The following trace is a kernel self test and not a bug!\n"); - dump_stack(); - init_timer(&backtrace_timer); - backtrace_timer.function = backtrace_test_timer; - mod_timer(&backtrace_timer, jiffies + 10); + backtrace_test_normal(); + backtrace_test_irq(); + backtrace_test_saved(); - msleep(10); printk("====[ end of backtrace testing ]====\n"); return 0; } diff --git a/kernel/capability.c b/kernel/capability.c index cfbe442..33e51e7 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -115,11 +115,229 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy) return 0; } +#ifndef CONFIG_SECURITY_FILE_CAPABILITIES + +/* + * Without filesystem capability support, we nominally support one process + * setting the capabilities of another + */ +static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, + kernel_cap_t *pIp, kernel_cap_t *pPp) +{ + struct task_struct *target; + int ret; + + spin_lock(&task_capability_lock); + read_lock(&tasklist_lock); + + if (pid && pid != task_pid_vnr(current)) { + target = find_task_by_vpid(pid); + if (!target) { + ret = -ESRCH; + goto out; + } + } else + target = current; + + ret = security_capget(target, pEp, pIp, pPp); + +out: + read_unlock(&tasklist_lock); + spin_unlock(&task_capability_lock); + + return ret; +} + +/* + * cap_set_pg - set capabilities for all processes in a given process + * group. We call this holding task_capability_lock and tasklist_lock. + */ +static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) +{ + struct task_struct *g, *target; + int ret = -EPERM; + int found = 0; + struct pid *pgrp; + + spin_lock(&task_capability_lock); + read_lock(&tasklist_lock); + + pgrp = find_vpid(pgrp_nr); + do_each_pid_task(pgrp, PIDTYPE_PGID, g) { + target = g; + while_each_thread(g, target) { + if (!security_capset_check(target, effective, + inheritable, permitted)) { + security_capset_set(target, effective, + inheritable, permitted); + ret = 0; + } + found = 1; + } + } while_each_pid_task(pgrp, PIDTYPE_PGID, g); + + read_unlock(&tasklist_lock); + spin_unlock(&task_capability_lock); + + if (!found) + ret = 0; + return ret; +} + +/* + * cap_set_all - set capabilities for all processes other than init + * and self. We call this holding task_capability_lock and tasklist_lock. + */ +static inline int cap_set_all(kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) +{ + struct task_struct *g, *target; + int ret = -EPERM; + int found = 0; + + spin_lock(&task_capability_lock); + read_lock(&tasklist_lock); + + do_each_thread(g, target) { + if (target == current + || is_container_init(target->group_leader)) + continue; + found = 1; + if (security_capset_check(target, effective, inheritable, + permitted)) + continue; + ret = 0; + security_capset_set(target, effective, inheritable, permitted); + } while_each_thread(g, target); + + read_unlock(&tasklist_lock); + spin_unlock(&task_capability_lock); + + if (!found) + ret = 0; + + return ret; +} + +/* + * Given the target pid does not refer to the current process we + * need more elaborate support... (This support is not present when + * filesystem capabilities are configured.) + */ +static inline int do_sys_capset_other_tasks(pid_t pid, kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) +{ + struct task_struct *target; + int ret; + + if (!capable(CAP_SETPCAP)) + return -EPERM; + + if (pid == -1) /* all procs other than current and init */ + return cap_set_all(effective, inheritable, permitted); + + else if (pid < 0) /* all procs in process group */ + return cap_set_pg(-pid, effective, inheritable, permitted); + + /* target != current */ + spin_lock(&task_capability_lock); + read_lock(&tasklist_lock); + + target = find_task_by_vpid(pid); + if (!target) + ret = -ESRCH; + else { + ret = security_capset_check(target, effective, inheritable, + permitted); + + /* having verified that the proposed changes are legal, + we now put them into effect. */ + if (!ret) + security_capset_set(target, effective, inheritable, + permitted); + } + + read_unlock(&tasklist_lock); + spin_unlock(&task_capability_lock); + + return ret; +} + +#else /* ie., def CONFIG_SECURITY_FILE_CAPABILITIES */ + +/* + * If we have configured with filesystem capability support, then the + * only thing that can change the capabilities of the current process + * is the current process. As such, we can't be in this code at the + * same time as we are in the process of setting capabilities in this + * process. The net result is that we can limit our use of locks to + * when we are reading the caps of another process. + */ +static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, + kernel_cap_t *pIp, kernel_cap_t *pPp) +{ + int ret; + + if (pid && (pid != task_pid_vnr(current))) { + struct task_struct *target; + + spin_lock(&task_capability_lock); + read_lock(&tasklist_lock); + + target = find_task_by_vpid(pid); + if (!target) + ret = -ESRCH; + else + ret = security_capget(target, pEp, pIp, pPp); + + read_unlock(&tasklist_lock); + spin_unlock(&task_capability_lock); + } else + ret = security_capget(current, pEp, pIp, pPp); + + return ret; +} + /* - * For sys_getproccap() and sys_setproccap(), any of the three - * capability set pointers may be NULL -- indicating that that set is - * uninteresting and/or not to be changed. + * With filesystem capability support configured, the kernel does not + * permit the changing of capabilities in one process by another + * process. (CAP_SETPCAP has much less broad semantics when configured + * this way.) */ +static inline int do_sys_capset_other_tasks(pid_t pid, + kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) +{ + return -EPERM; +} + +#endif /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ + +/* + * Atomically modify the effective capabilities returning the original + * value. No permission check is performed here - it is assumed that the + * caller is permitted to set the desired effective capabilities. + */ +kernel_cap_t cap_set_effective(const kernel_cap_t pE_new) +{ + kernel_cap_t pE_old; + + spin_lock(&task_capability_lock); + + pE_old = current->cap_effective; + current->cap_effective = pE_new; + + spin_unlock(&task_capability_lock); + + return pE_old; +} + +EXPORT_SYMBOL(cap_set_effective); /** * sys_capget - get the capabilities of a given process. @@ -134,7 +352,6 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr) { int ret = 0; pid_t pid; - struct task_struct *target; unsigned tocopy; kernel_cap_t pE, pI, pP; @@ -148,23 +365,7 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr) if (pid < 0) return -EINVAL; - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - if (pid && pid != task_pid_vnr(current)) { - target = find_task_by_vpid(pid); - if (!target) { - ret = -ESRCH; - goto out; - } - } else - target = current; - - ret = security_capget(target, &pE, &pI, &pP); - -out: - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); + ret = cap_get_target_pid(pid, &pE, &pI, &pP); if (!ret) { struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; @@ -195,7 +396,6 @@ out: * before modification is attempted and the application * fails. */ - if (copy_to_user(dataptr, kdata, tocopy * sizeof(struct __user_cap_data_struct))) { return -EFAULT; @@ -205,70 +405,8 @@ out: return ret; } -/* - * cap_set_pg - set capabilities for all processes in a given process - * group. We call this holding task_capability_lock and tasklist_lock. - */ -static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - struct task_struct *g, *target; - int ret = -EPERM; - int found = 0; - struct pid *pgrp; - - pgrp = find_vpid(pgrp_nr); - do_each_pid_task(pgrp, PIDTYPE_PGID, g) { - target = g; - while_each_thread(g, target) { - if (!security_capset_check(target, effective, - inheritable, - permitted)) { - security_capset_set(target, effective, - inheritable, - permitted); - ret = 0; - } - found = 1; - } - } while_each_pid_task(pgrp, PIDTYPE_PGID, g); - - if (!found) - ret = 0; - return ret; -} - -/* - * cap_set_all - set capabilities for all processes other than init - * and self. We call this holding task_capability_lock and tasklist_lock. - */ -static inline int cap_set_all(kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) -{ - struct task_struct *g, *target; - int ret = -EPERM; - int found = 0; - - do_each_thread(g, target) { - if (target == current || is_container_init(target->group_leader)) - continue; - found = 1; - if (security_capset_check(target, effective, inheritable, - permitted)) - continue; - ret = 0; - security_capset_set(target, effective, inheritable, permitted); - } while_each_thread(g, target); - - if (!found) - ret = 0; - return ret; -} - /** - * sys_capset - set capabilities for a process or a group of processes + * sys_capset - set capabilities for a process or (*) a group of processes * @header: pointer to struct that contains capability version and * target pid data * @data: pointer to struct that contains the effective, permitted, @@ -292,7 +430,6 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; unsigned i, tocopy; kernel_cap_t inheritable, permitted, effective; - struct task_struct *target; int ret; pid_t pid; @@ -303,9 +440,6 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) if (get_user(pid, &header->pid)) return -EFAULT; - if (pid && pid != task_pid_vnr(current) && !capable(CAP_SETPCAP)) - return -EPERM; - if (copy_from_user(&kdata, data, tocopy * sizeof(struct __user_cap_data_struct))) { return -EFAULT; @@ -323,55 +457,51 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) i++; } - spin_lock(&task_capability_lock); - read_lock(&tasklist_lock); - - if (pid > 0 && pid != task_pid_vnr(current)) { - target = find_task_by_vpid(pid); - if (!target) { - ret = -ESRCH; - goto out; - } - } else - target = current; - - ret = 0; - - /* having verified that the proposed changes are legal, - we now put them into effect. */ - if (pid < 0) { - if (pid == -1) /* all procs other than current and init */ - ret = cap_set_all(&effective, &inheritable, &permitted); + if (pid && (pid != task_pid_vnr(current))) + ret = do_sys_capset_other_tasks(pid, &effective, &inheritable, + &permitted); + else { + /* + * This lock is required even when filesystem + * capability support is configured - it protects the + * sys_capget() call from returning incorrect data in + * the case that the targeted process is not the + * current one. + */ + spin_lock(&task_capability_lock); - else /* all procs in process group */ - ret = cap_set_pg(-pid, &effective, &inheritable, - &permitted); - } else { - ret = security_capset_check(target, &effective, &inheritable, + ret = security_capset_check(current, &effective, &inheritable, &permitted); + /* + * Having verified that the proposed changes are + * legal, we now put them into effect. + */ if (!ret) - security_capset_set(target, &effective, &inheritable, + security_capset_set(current, &effective, &inheritable, &permitted); + spin_unlock(&task_capability_lock); } -out: - read_unlock(&tasklist_lock); - spin_unlock(&task_capability_lock); return ret; } -int __capable(struct task_struct *t, int cap) +/** + * capable - Determine if the current task has a superior capability in effect + * @cap: The capability to be tested for + * + * Return true if the current task has the given superior capability currently + * available for use, false if not. + * + * This sets PF_SUPERPRIV on the task if the capability is available on the + * assumption that it's about to be used. + */ +int capable(int cap) { - if (security_capable(t, cap) == 0) { - t->flags |= PF_SUPERPRIV; + if (has_capability(current, cap)) { + current->flags |= PF_SUPERPRIV; return 1; } return 0; } - -int capable(int cap) -{ - return __capable(current, cap); -} EXPORT_SYMBOL(capable); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 15ac0e1..a0123d7 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -45,6 +45,7 @@ #include <linux/delayacct.h> #include <linux/cgroupstats.h> #include <linux/hash.h> +#include <linux/namei.h> #include <asm/atomic.h> @@ -89,11 +90,7 @@ struct cgroupfs_root { /* Hierarchy-specific flags */ unsigned long flags; - /* The path to use for release notifications. No locking - * between setting and use - so if userspace updates this - * while child cgroups exist, you could miss a - * notification. We ensure that it's always a valid - * NUL-terminated string */ + /* The path to use for release notifications. */ char release_agent_path[PATH_MAX]; }; @@ -118,7 +115,7 @@ static int root_count; * extra work in the fork/exit path if none of the subsystems need to * be called. */ -static int need_forkexit_callback; +static int need_forkexit_callback __read_mostly; static int need_mm_owner_callback __read_mostly; /* convenient tests for these bits */ @@ -220,7 +217,7 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) * task until after the first call to cgroup_iter_start(). This * reduces the fork()/exit() overhead for people who have cgroups * compiled into their kernel but not actually in use */ -static int use_task_css_set_links; +static int use_task_css_set_links __read_mostly; /* When we create or destroy a css_set, the operation simply * takes/releases a reference count on all the cgroups referenced @@ -241,17 +238,20 @@ static int use_task_css_set_links; */ static void unlink_css_set(struct css_set *cg) { + struct cg_cgroup_link *link; + struct cg_cgroup_link *saved_link; + write_lock(&css_set_lock); hlist_del(&cg->hlist); css_set_count--; - while (!list_empty(&cg->cg_links)) { - struct cg_cgroup_link *link; - link = list_entry(cg->cg_links.next, - struct cg_cgroup_link, cg_link_list); + + list_for_each_entry_safe(link, saved_link, &cg->cg_links, + cg_link_list) { list_del(&link->cg_link_list); list_del(&link->cgrp_link_list); kfree(link); } + write_unlock(&css_set_lock); } @@ -355,6 +355,17 @@ static struct css_set *find_existing_css_set( return NULL; } +static void free_cg_links(struct list_head *tmp) +{ + struct cg_cgroup_link *link; + struct cg_cgroup_link *saved_link; + + list_for_each_entry_safe(link, saved_link, tmp, cgrp_link_list) { + list_del(&link->cgrp_link_list); + kfree(link); + } +} + /* * allocate_cg_links() allocates "count" cg_cgroup_link structures * and chains them on tmp through their cgrp_link_list fields. Returns 0 on @@ -368,13 +379,7 @@ static int allocate_cg_links(int count, struct list_head *tmp) for (i = 0; i < count; i++) { link = kmalloc(sizeof(*link), GFP_KERNEL); if (!link) { - while (!list_empty(tmp)) { - link = list_entry(tmp->next, - struct cg_cgroup_link, - cgrp_link_list); - list_del(&link->cgrp_link_list); - kfree(link); - } + free_cg_links(tmp); return -ENOMEM; } list_add(&link->cgrp_link_list, tmp); @@ -382,18 +387,6 @@ static int allocate_cg_links(int count, struct list_head *tmp) return 0; } -static void free_cg_links(struct list_head *tmp) -{ - while (!list_empty(tmp)) { - struct cg_cgroup_link *link; - link = list_entry(tmp->next, - struct cg_cgroup_link, - cgrp_link_list); - list_del(&link->cgrp_link_list); - kfree(link); - } -} - /* * find_css_set() takes an existing cgroup group and a * cgroup object, and returns a css_set object that's @@ -415,11 +408,11 @@ static struct css_set *find_css_set( /* First see if we already have a cgroup group that matches * the desired set */ - write_lock(&css_set_lock); + read_lock(&css_set_lock); res = find_existing_css_set(oldcg, cgrp, template); if (res) get_css_set(res); - write_unlock(&css_set_lock); + read_unlock(&css_set_lock); if (res) return res; @@ -507,10 +500,6 @@ static struct css_set *find_css_set( * knows that the cgroup won't be removed, as cgroup_rmdir() * needs that mutex. * - * The cgroup_common_file_write handler for operations that modify - * the cgroup hierarchy holds cgroup_mutex across the entire operation, - * single threading all such cgroup modifications across the system. - * * The fork and exit callbacks cgroup_fork() and cgroup_exit(), don't * (usually) take cgroup_mutex. These are the two most performance * critical pieces of code here. The exception occurs on cgroup_exit(), @@ -962,7 +951,6 @@ static int cgroup_get_sb(struct file_system_type *fs_type, struct super_block *sb; struct cgroupfs_root *root; struct list_head tmp_cg_links; - INIT_LIST_HEAD(&tmp_cg_links); /* First find the desired set of subsystems */ ret = parse_cgroupfs_options(data, &opts); @@ -1093,6 +1081,8 @@ static void cgroup_kill_sb(struct super_block *sb) { struct cgroupfs_root *root = sb->s_fs_info; struct cgroup *cgrp = &root->top_cgroup; int ret; + struct cg_cgroup_link *link; + struct cg_cgroup_link *saved_link; BUG_ON(!root); @@ -1112,10 +1102,9 @@ static void cgroup_kill_sb(struct super_block *sb) { * root cgroup */ write_lock(&css_set_lock); - while (!list_empty(&cgrp->css_sets)) { - struct cg_cgroup_link *link; - link = list_entry(cgrp->css_sets.next, - struct cg_cgroup_link, cgrp_link_list); + + list_for_each_entry_safe(link, saved_link, &cgrp->css_sets, + cgrp_link_list) { list_del(&link->cg_link_list); list_del(&link->cgrp_link_list); kfree(link); @@ -1281,18 +1270,14 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) } /* - * Attach task with pid 'pid' to cgroup 'cgrp'. Call with - * cgroup_mutex, may take task_lock of task + * Attach task with pid 'pid' to cgroup 'cgrp'. Call with cgroup_mutex + * held. May take task_lock of task */ -static int attach_task_by_pid(struct cgroup *cgrp, char *pidbuf) +static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) { - pid_t pid; struct task_struct *tsk; int ret; - if (sscanf(pidbuf, "%d", &pid) != 1) - return -EIO; - if (pid) { rcu_read_lock(); tsk = find_task_by_vpid(pid); @@ -1318,6 +1303,16 @@ static int attach_task_by_pid(struct cgroup *cgrp, char *pidbuf) return ret; } +static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid) +{ + int ret; + if (!cgroup_lock_live_group(cgrp)) + return -ENODEV; + ret = attach_task_by_pid(cgrp, pid); + cgroup_unlock(); + return ret; +} + /* The various types of files and directories in a cgroup file system */ enum cgroup_filetype { FILE_ROOT, @@ -1327,12 +1322,54 @@ enum cgroup_filetype { FILE_RELEASE_AGENT, }; +/** + * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. + * @cgrp: the cgroup to be checked for liveness + * + * On success, returns true; the lock should be later released with + * cgroup_unlock(). On failure returns false with no lock held. + */ +bool cgroup_lock_live_group(struct cgroup *cgrp) +{ + mutex_lock(&cgroup_mutex); + if (cgroup_is_removed(cgrp)) { + mutex_unlock(&cgroup_mutex); + return false; + } + return true; +} + +static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft, + const char *buffer) +{ + BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX); + if (!cgroup_lock_live_group(cgrp)) + return -ENODEV; + strcpy(cgrp->root->release_agent_path, buffer); + cgroup_unlock(); + return 0; +} + +static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft, + struct seq_file *seq) +{ + if (!cgroup_lock_live_group(cgrp)) + return -ENODEV; + seq_puts(seq, cgrp->root->release_agent_path); + seq_putc(seq, '\n'); + cgroup_unlock(); + return 0; +} + +/* A buffer size big enough for numbers or short strings */ +#define CGROUP_LOCAL_BUFFER_SIZE 64 + static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft, struct file *file, const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) { - char buffer[64]; + char buffer[CGROUP_LOCAL_BUFFER_SIZE]; int retval = 0; char *end; @@ -1361,68 +1398,39 @@ static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft, return retval; } -static ssize_t cgroup_common_file_write(struct cgroup *cgrp, - struct cftype *cft, - struct file *file, - const char __user *userbuf, - size_t nbytes, loff_t *unused_ppos) +static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft, + struct file *file, + const char __user *userbuf, + size_t nbytes, loff_t *unused_ppos) { - enum cgroup_filetype type = cft->private; - char *buffer; + char local_buffer[CGROUP_LOCAL_BUFFER_SIZE]; int retval = 0; + size_t max_bytes = cft->max_write_len; + char *buffer = local_buffer; - if (nbytes >= PATH_MAX) + if (!max_bytes) + max_bytes = sizeof(local_buffer) - 1; + if (nbytes >= max_bytes) return -E2BIG; - - /* +1 for nul-terminator */ - buffer = kmalloc(nbytes + 1, GFP_KERNEL); - if (buffer == NULL) - return -ENOMEM; - - if (copy_from_user(buffer, userbuf, nbytes)) { + /* Allocate a dynamic buffer if we need one */ + if (nbytes >= sizeof(local_buffer)) { + buffer = kmalloc(nbytes + 1, GFP_KERNEL); + if (buffer == NULL) + return -ENOMEM; + } + if (nbytes && copy_from_user(buffer, userbuf, nbytes)) { retval = -EFAULT; - goto out1; + goto out; } - buffer[nbytes] = 0; /* nul-terminate */ - strstrip(buffer); /* strip -just- trailing whitespace */ - mutex_lock(&cgroup_mutex); - - /* - * This was already checked for in cgroup_file_write(), but - * check again now we're holding cgroup_mutex. - */ - if (cgroup_is_removed(cgrp)) { - retval = -ENODEV; - goto out2; - } - - switch (type) { - case FILE_TASKLIST: - retval = attach_task_by_pid(cgrp, buffer); - break; - case FILE_NOTIFY_ON_RELEASE: - clear_bit(CGRP_RELEASABLE, &cgrp->flags); - if (simple_strtoul(buffer, NULL, 10) != 0) - set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); - else - clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); - break; - case FILE_RELEASE_AGENT: - BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX); - strcpy(cgrp->root->release_agent_path, buffer); - break; - default: - retval = -EINVAL; - goto out2; - } - - if (retval == 0) + buffer[nbytes] = 0; /* nul-terminate */ + strstrip(buffer); + retval = cft->write_string(cgrp, cft, buffer); + if (!retval) retval = nbytes; -out2: - mutex_unlock(&cgroup_mutex); -out1: - kfree(buffer); +out: + if (buffer != local_buffer) + kfree(buffer); return retval; } @@ -1438,6 +1446,8 @@ static ssize_t cgroup_file_write(struct file *file, const char __user *buf, return cft->write(cgrp, cft, file, buf, nbytes, ppos); if (cft->write_u64 || cft->write_s64) return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos); + if (cft->write_string) + return cgroup_write_string(cgrp, cft, file, buf, nbytes, ppos); if (cft->trigger) { int ret = cft->trigger(cgrp, (unsigned int)cft->private); return ret ? ret : nbytes; @@ -1450,7 +1460,7 @@ static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft, char __user *buf, size_t nbytes, loff_t *ppos) { - char tmp[64]; + char tmp[CGROUP_LOCAL_BUFFER_SIZE]; u64 val = cft->read_u64(cgrp, cft); int len = sprintf(tmp, "%llu\n", (unsigned long long) val); @@ -1462,56 +1472,13 @@ static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft, char __user *buf, size_t nbytes, loff_t *ppos) { - char tmp[64]; + char tmp[CGROUP_LOCAL_BUFFER_SIZE]; s64 val = cft->read_s64(cgrp, cft); int len = sprintf(tmp, "%lld\n", (long long) val); return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); } -static ssize_t cgroup_common_file_read(struct cgroup *cgrp, - struct cftype *cft, - struct file *file, - char __user *buf, - size_t nbytes, loff_t *ppos) -{ - enum cgroup_filetype type = cft->private; - char *page; - ssize_t retval = 0; - char *s; - - if (!(page = (char *)__get_free_page(GFP_KERNEL))) - return -ENOMEM; - - s = page; - - switch (type) { - case FILE_RELEASE_AGENT: - { - struct cgroupfs_root *root; - size_t n; - mutex_lock(&cgroup_mutex); - root = cgrp->root; - n = strnlen(root->release_agent_path, - sizeof(root->release_agent_path)); - n = min(n, (size_t) PAGE_SIZE); - strncpy(s, root->release_agent_path, n); - mutex_unlock(&cgroup_mutex); - s += n; - break; - } - default: - retval = -EINVAL; - goto out; - } - *s++ = '\n'; - - retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page); -out: - free_page((unsigned long)page); - return retval; -} - static ssize_t cgroup_file_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { @@ -1560,7 +1527,7 @@ static int cgroup_seqfile_show(struct seq_file *m, void *arg) return cft->read_seq_string(state->cgroup, cft, m); } -int cgroup_seqfile_release(struct inode *inode, struct file *file) +static int cgroup_seqfile_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; kfree(seq->private); @@ -1569,6 +1536,7 @@ int cgroup_seqfile_release(struct inode *inode, struct file *file) static struct file_operations cgroup_seqfile_operations = { .read = seq_read, + .write = cgroup_file_write, .llseek = seq_lseek, .release = cgroup_seqfile_release, }; @@ -1756,15 +1724,11 @@ int cgroup_add_files(struct cgroup *cgrp, int cgroup_task_count(const struct cgroup *cgrp) { int count = 0; - struct list_head *l; + struct cg_cgroup_link *link; read_lock(&css_set_lock); - l = cgrp->css_sets.next; - while (l != &cgrp->css_sets) { - struct cg_cgroup_link *link = - list_entry(l, struct cg_cgroup_link, cgrp_link_list); + list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) { count += atomic_read(&link->cg->ref.refcount); - l = l->next; } read_unlock(&css_set_lock); return count; @@ -2227,6 +2191,18 @@ static u64 cgroup_read_notify_on_release(struct cgroup *cgrp, return notify_on_release(cgrp); } +static int cgroup_write_notify_on_release(struct cgroup *cgrp, + struct cftype *cft, + u64 val) +{ + clear_bit(CGRP_RELEASABLE, &cgrp->flags); + if (val) + set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); + else + clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); + return 0; +} + /* * for the common functions, 'private' gives the type of file */ @@ -2235,7 +2211,7 @@ static struct cftype files[] = { .name = "tasks", .open = cgroup_tasks_open, .read = cgroup_tasks_read, - .write = cgroup_common_file_write, + .write_u64 = cgroup_tasks_write, .release = cgroup_tasks_release, .private = FILE_TASKLIST, }, @@ -2243,15 +2219,16 @@ static struct cftype files[] = { { .name = "notify_on_release", .read_u64 = cgroup_read_notify_on_release, - .write = cgroup_common_file_write, + .write_u64 = cgroup_write_notify_on_release, .private = FILE_NOTIFY_ON_RELEASE, }, }; static struct cftype cft_release_agent = { .name = "release_agent", - .read = cgroup_common_file_read, - .write = cgroup_common_file_write, + .read_seq_string = cgroup_release_agent_show, + .write_string = cgroup_release_agent_write, + .max_write_len = PATH_MAX, .private = FILE_RELEASE_AGENT, }; @@ -2391,7 +2368,7 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode) return cgroup_create(c_parent, dentry, mode | S_IFDIR); } -static inline int cgroup_has_css_refs(struct cgroup *cgrp) +static int cgroup_has_css_refs(struct cgroup *cgrp) { /* Check the reference count on each subsystem. Since we * already established that there are no tasks in the @@ -2761,14 +2738,15 @@ void cgroup_fork_callbacks(struct task_struct *child) */ void cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new) { - struct cgroup *oldcgrp, *newcgrp; + struct cgroup *oldcgrp, *newcgrp = NULL; if (need_mm_owner_callback) { int i; for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; oldcgrp = task_cgroup(old, ss->subsys_id); - newcgrp = task_cgroup(new, ss->subsys_id); + if (new) + newcgrp = task_cgroup(new, ss->subsys_id); if (oldcgrp == newcgrp) continue; if (ss->mm_owner_changed) @@ -2869,16 +2847,17 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) * cgroup_clone - clone the cgroup the given subsystem is attached to * @tsk: the task to be moved * @subsys: the given subsystem + * @nodename: the name for the new cgroup * * Duplicate the current cgroup in the hierarchy that the given * subsystem is attached to, and move this task into the new * child. */ -int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys) +int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys, + char *nodename) { struct dentry *dentry; int ret = 0; - char nodename[MAX_CGROUP_TYPE_NAMELEN]; struct cgroup *parent, *child; struct inode *inode; struct css_set *cg; @@ -2903,8 +2882,6 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys) cg = tsk->cgroups; parent = task_cgroup(tsk, subsys->subsys_id); - snprintf(nodename, MAX_CGROUP_TYPE_NAMELEN, "%d", tsk->pid); - /* Pin the hierarchy */ atomic_inc(&parent->root->sb->s_active); @@ -3078,27 +3055,24 @@ static void cgroup_release_agent(struct work_struct *work) while (!list_empty(&release_list)) { char *argv[3], *envp[3]; int i; - char *pathbuf; + char *pathbuf = NULL, *agentbuf = NULL; struct cgroup *cgrp = list_entry(release_list.next, struct cgroup, release_list); list_del_init(&cgrp->release_list); spin_unlock(&release_list_lock); pathbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!pathbuf) { - spin_lock(&release_list_lock); - continue; - } - - if (cgroup_path(cgrp, pathbuf, PAGE_SIZE) < 0) { - kfree(pathbuf); - spin_lock(&release_list_lock); - continue; - } + if (!pathbuf) + goto continue_free; + if (cgroup_path(cgrp, pathbuf, PAGE_SIZE) < 0) + goto continue_free; + agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL); + if (!agentbuf) + goto continue_free; i = 0; - argv[i++] = cgrp->root->release_agent_path; - argv[i++] = (char *)pathbuf; + argv[i++] = agentbuf; + argv[i++] = pathbuf; argv[i] = NULL; i = 0; @@ -3112,8 +3086,10 @@ static void cgroup_release_agent(struct work_struct *work) * be a slow process */ mutex_unlock(&cgroup_mutex); call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); - kfree(pathbuf); mutex_lock(&cgroup_mutex); + continue_free: + kfree(pathbuf); + kfree(agentbuf); spin_lock(&release_list_lock); } spin_unlock(&release_list_lock); diff --git a/kernel/cpu.c b/kernel/cpu.c index c77bc3a..86d4904 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -15,6 +15,28 @@ #include <linux/stop_machine.h> #include <linux/mutex.h> +/* + * Represents all cpu's present in the system + * In systems capable of hotplug, this map could dynamically grow + * as new cpu's are detected in the system via any platform specific + * method, such as ACPI for e.g. + */ +cpumask_t cpu_present_map __read_mostly; +EXPORT_SYMBOL(cpu_present_map); + +#ifndef CONFIG_SMP + +/* + * Represents all cpu's that are currently online. + */ +cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL; +EXPORT_SYMBOL(cpu_online_map); + +cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; +EXPORT_SYMBOL(cpu_possible_map); + +#else /* CONFIG_SMP */ + /* Serializes the updates to cpu_online_map, cpu_present_map */ static DEFINE_MUTEX(cpu_add_remove_lock); @@ -42,6 +64,8 @@ void __init cpu_hotplug_init(void) cpu_hotplug.refcount = 0; } +cpumask_t cpu_active_map; + #ifdef CONFIG_HOTPLUG_CPU void get_online_cpus(void) @@ -175,13 +199,14 @@ static int __ref take_cpu_down(void *_param) struct take_cpu_down_param *param = _param; int err; - raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod, - param->hcpu); /* Ensure this CPU doesn't handle any more interrupts. */ err = __cpu_disable(); if (err < 0) return err; + raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod, + param->hcpu); + /* Force idle task to run as soon as we yield: it should immediately notice cpu is offline and die quickly. */ sched_idle_next(); @@ -192,7 +217,6 @@ static int __ref take_cpu_down(void *_param) static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) { int err, nr_calls = 0; - struct task_struct *p; cpumask_t old_allowed, tmp; void *hcpu = (void *)(long)cpu; unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; @@ -225,21 +249,18 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) cpus_setall(tmp); cpu_clear(cpu, tmp); set_cpus_allowed_ptr(current, &tmp); + tmp = cpumask_of_cpu(cpu); - p = __stop_machine_run(take_cpu_down, &tcd_param, cpu); - - if (IS_ERR(p) || cpu_online(cpu)) { + err = __stop_machine(take_cpu_down, &tcd_param, &tmp); + if (err) { /* CPU didn't die: tell everyone. Can't complain. */ if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, hcpu) == NOTIFY_BAD) BUG(); - if (IS_ERR(p)) { - err = PTR_ERR(p); - goto out_allowed; - } - goto out_thread; + goto out_allowed; } + BUG_ON(cpu_online(cpu)); /* Wait for it to sleep (leaving idle task). */ while (!idle_cpu(cpu)) @@ -255,12 +276,15 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) check_for_tasks(cpu); -out_thread: - err = kthread_stop(p); out_allowed: set_cpus_allowed_ptr(current, &old_allowed); out_release: cpu_hotplug_done(); + if (!err) { + if (raw_notifier_call_chain(&cpu_chain, CPU_POST_DEAD | mod, + hcpu) == NOTIFY_BAD) + BUG(); + } return err; } @@ -269,14 +293,34 @@ int __ref cpu_down(unsigned int cpu) int err = 0; cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_down(cpu, 0); + goto out; + } + + cpu_clear(cpu, cpu_active_map); + + /* + * Make sure the all cpus did the reschedule and are not + * using stale version of the cpu_active_map. + * This is not strictly necessary becuase stop_machine() + * that we run down the line already provides the required + * synchronization. But it's really a side effect and we do not + * want to depend on the innards of the stop_machine here. + */ + synchronize_sched(); + err = _cpu_down(cpu, 0); + + if (cpu_online(cpu)) + cpu_set(cpu, cpu_active_map); + +out: cpu_maps_update_done(); return err; } +EXPORT_SYMBOL(cpu_down); #endif /*CONFIG_HOTPLUG_CPU*/ /* Requires cpu_add_remove_lock to be held */ @@ -306,6 +350,8 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) goto out_notify; BUG_ON(!cpu_online(cpu)); + cpu_set(cpu, cpu_active_map); + /* Now call notifier in preparation. */ raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu); @@ -324,7 +370,7 @@ int __cpuinit cpu_up(unsigned int cpu) if (!cpu_isset(cpu, cpu_possible_map)) { printk(KERN_ERR "can't online cpu %d because it is not " "configured as may-hotadd at boot time\n", cpu); -#if defined(CONFIG_IA64) || defined(CONFIG_X86_64) || defined(CONFIG_S390) +#if defined(CONFIG_IA64) || defined(CONFIG_X86_64) printk(KERN_ERR "please check additional_cpus= boot " "parameter\n"); #endif @@ -332,11 +378,15 @@ int __cpuinit cpu_up(unsigned int cpu) } cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_up(cpu, 0); + goto out; + } + err = _cpu_up(cpu, 0); + +out: cpu_maps_update_done(); return err; } @@ -390,7 +440,7 @@ void __ref enable_nonboot_cpus(void) goto out; printk("Enabling non-boot CPUs ...\n"); - for_each_cpu_mask(cpu, frozen_cpus) { + for_each_cpu_mask_nr(cpu, frozen_cpus) { error = _cpu_up(cpu, 1); if (!error) { printk("CPU%d is up\n", cpu); @@ -403,3 +453,49 @@ out: cpu_maps_update_done(); } #endif /* CONFIG_PM_SLEEP_SMP */ + +/** + * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers + * @cpu: cpu that just started + * + * This function calls the cpu_chain notifiers with CPU_STARTING. + * It must be called by the arch code on the new cpu, before the new cpu + * enables interrupts and before the "boot" cpu returns from __cpu_up(). + */ +void notify_cpu_starting(unsigned int cpu) +{ + unsigned long val = CPU_STARTING; + +#ifdef CONFIG_PM_SLEEP_SMP + if (cpu_isset(cpu, frozen_cpus)) + val = CPU_STARTING_FROZEN; +#endif /* CONFIG_PM_SLEEP_SMP */ + raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu); +} + +#endif /* CONFIG_SMP */ + +/* + * cpu_bit_bitmap[] is a special, "compressed" data structure that + * represents all NR_CPUS bits binary values of 1<<nr. + * + * It is used by cpumask_of_cpu() to get a constant address to a CPU + * mask value that has a single bit set only. + */ + +/* cpu_bit_bitmap[0] is empty - so we can back into it */ +#define MASK_DECLARE_1(x) [x+1][0] = 1UL << (x) +#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) +#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) +#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) + +const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { + + MASK_DECLARE_8(0), MASK_DECLARE_8(8), + MASK_DECLARE_8(16), MASK_DECLARE_8(24), +#if BITS_PER_LONG > 32 + MASK_DECLARE_8(32), MASK_DECLARE_8(40), + MASK_DECLARE_8(48), MASK_DECLARE_8(56), +#endif +}; +EXPORT_SYMBOL_GPL(cpu_bit_bitmap); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 9fceb97..eab7bd6 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -14,6 +14,8 @@ * 2003-10-22 Updates by Stephen Hemminger. * 2004 May-July Rework by Paul Jackson. * 2006 Rework by Paul Menage to use generic cgroups + * 2008 Rework of the scheduler domains and CPU hotplug handling + * by Max Krasnyansky * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of the Linux @@ -54,7 +56,6 @@ #include <asm/uaccess.h> #include <asm/atomic.h> #include <linux/mutex.h> -#include <linux/kfifo.h> #include <linux/workqueue.h> #include <linux/cgroup.h> @@ -227,10 +228,6 @@ static struct cpuset top_cpuset = { * The task_struct fields mems_allowed and mems_generation may only * be accessed in the context of that task, so require no locks. * - * The cpuset_common_file_write handler for operations that modify - * the cpuset hierarchy holds cgroup_mutex across the entire operation, - * single threading all such cpuset modifications across the system. - * * The cpuset_common_file_read() handlers only hold callback_mutex across * small pieces of code, such as when reading out possibly multi-word * cpumasks and nodemasks. @@ -241,9 +238,11 @@ static struct cpuset top_cpuset = { static DEFINE_MUTEX(callback_mutex); -/* This is ugly, but preserves the userspace API for existing cpuset +/* + * This is ugly, but preserves the userspace API for existing cpuset * users. If someone tries to mount the "cpuset" filesystem, we - * silently switch it to mount "cgroup" instead */ + * silently switch it to mount "cgroup" instead + */ static int cpuset_get_sb(struct file_system_type *fs_type, int flags, const char *unused_dev_name, void *data, struct vfsmount *mnt) @@ -369,7 +368,7 @@ void cpuset_update_task_memory_state(void) my_cpusets_mem_gen = top_cpuset.mems_generation; } else { rcu_read_lock(); - my_cpusets_mem_gen = task_cs(current)->mems_generation; + my_cpusets_mem_gen = task_cs(tsk)->mems_generation; rcu_read_unlock(); } @@ -478,10 +477,9 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) } /* - * Helper routine for rebuild_sched_domains(). + * Helper routine for generate_sched_domains(). * Do cpusets a, b have overlapping cpus_allowed masks? */ - static int cpusets_overlap(struct cpuset *a, struct cpuset *b) { return cpus_intersects(a->cpus_allowed, b->cpus_allowed); @@ -490,29 +488,48 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) static void update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) { - if (!dattr) - return; if (dattr->relax_domain_level < c->relax_domain_level) dattr->relax_domain_level = c->relax_domain_level; return; } +static void +update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) +{ + LIST_HEAD(q); + + list_add(&c->stack_list, &q); + while (!list_empty(&q)) { + struct cpuset *cp; + struct cgroup *cont; + struct cpuset *child; + + cp = list_first_entry(&q, struct cpuset, stack_list); + list_del(q.next); + + if (cpus_empty(cp->cpus_allowed)) + continue; + + if (is_sched_load_balance(cp)) + update_domain_attr(dattr, cp); + + list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { + child = cgroup_cs(cont); + list_add_tail(&child->stack_list, &q); + } + } +} + /* - * rebuild_sched_domains() + * generate_sched_domains() * - * If the flag 'sched_load_balance' of any cpuset with non-empty - * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset - * which has that flag enabled, or if any cpuset with a non-empty - * 'cpus' is removed, then call this routine to rebuild the - * scheduler's dynamic sched domains. - * - * This routine builds a partial partition of the systems CPUs - * (the set of non-overlappping cpumask_t's in the array 'part' - * below), and passes that partial partition to the kernel/sched.c - * partition_sched_domains() routine, which will rebuild the - * schedulers load balancing domains (sched domains) as specified - * by that partial partition. A 'partial partition' is a set of - * non-overlapping subsets whose union is a subset of that set. + * This function builds a partial partition of the systems CPUs + * A 'partial partition' is a set of non-overlapping subsets whose + * union is a subset of that set. + * The output of this function needs to be passed to kernel/sched.c + * partition_sched_domains() routine, which will rebuild the scheduler's + * load balancing domains (sched domains) as specified by that partial + * partition. * * See "What is sched_load_balance" in Documentation/cpusets.txt * for a background explanation of this. @@ -522,16 +539,10 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) * domains when operating in the severe memory shortage situations * that could cause allocation failures below. * - * Call with cgroup_mutex held. May take callback_mutex during - * call due to the kfifo_alloc() and kmalloc() calls. May nest - * a call to the get_online_cpus()/put_online_cpus() pair. - * Must not be called holding callback_mutex, because we must not - * call get_online_cpus() while holding callback_mutex. Elsewhere - * the kernel nests callback_mutex inside get_online_cpus() calls. - * So the reverse nesting would risk an ABBA deadlock. + * Must be called with cgroup_lock held. * * The three key local variables below are: - * q - a kfifo queue of cpuset pointers, used to implement a + * q - a linked-list queue of cpuset pointers, used to implement a * top-down scan of all cpusets. This scan loads a pointer * to each cpuset marked is_sched_load_balance into the * array 'csa'. For our purposes, rebuilding the schedulers @@ -563,10 +574,10 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) * element of the partition (one sched domain) to be passed to * partition_sched_domains(). */ - -static void rebuild_sched_domains(void) +static int generate_sched_domains(cpumask_t **domains, + struct sched_domain_attr **attributes) { - struct kfifo *q; /* queue of cpusets to be scanned */ + LIST_HEAD(q); /* queue of cpusets to be scanned */ struct cpuset *cp; /* scans q */ struct cpuset **csa; /* array of all cpuset ptrs */ int csn; /* how many cpuset ptrs in csa so far */ @@ -576,44 +587,58 @@ static void rebuild_sched_domains(void) int ndoms; /* number of sched domains in result */ int nslot; /* next empty doms[] cpumask_t slot */ - q = NULL; - csa = NULL; + ndoms = 0; doms = NULL; dattr = NULL; + csa = NULL; /* Special case for the 99% of systems with one, full, sched domain */ if (is_sched_load_balance(&top_cpuset)) { - ndoms = 1; doms = kmalloc(sizeof(cpumask_t), GFP_KERNEL); if (!doms) - goto rebuild; + goto done; + dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL); if (dattr) { *dattr = SD_ATTR_INIT; - update_domain_attr(dattr, &top_cpuset); + update_domain_attr_tree(dattr, &top_cpuset); } *doms = top_cpuset.cpus_allowed; - goto rebuild; - } - q = kfifo_alloc(number_of_cpusets * sizeof(cp), GFP_KERNEL, NULL); - if (IS_ERR(q)) + ndoms = 1; goto done; + } + csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL); if (!csa) goto done; csn = 0; - cp = &top_cpuset; - __kfifo_put(q, (void *)&cp, sizeof(cp)); - while (__kfifo_get(q, (void *)&cp, sizeof(cp))) { + list_add(&top_cpuset.stack_list, &q); + while (!list_empty(&q)) { struct cgroup *cont; struct cpuset *child; /* scans child cpusets of cp */ - if (is_sched_load_balance(cp)) + + cp = list_first_entry(&q, struct cpuset, stack_list); + list_del(q.next); + + if (cpus_empty(cp->cpus_allowed)) + continue; + + /* + * All child cpusets contain a subset of the parent's cpus, so + * just skip them, and then we call update_domain_attr_tree() + * to calc relax_domain_level of the corresponding sched + * domain. + */ + if (is_sched_load_balance(cp)) { csa[csn++] = cp; + continue; + } + list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { child = cgroup_cs(cont); - __kfifo_put(q, (void *)&child, sizeof(cp)); + list_add_tail(&child->stack_list, &q); } } @@ -644,91 +669,141 @@ restart: } } - /* Convert <csn, csa> to <ndoms, doms> */ + /* + * Now we know how many domains to create. + * Convert <csn, csa> to <ndoms, doms> and populate cpu masks. + */ doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL); - if (!doms) - goto rebuild; + if (!doms) { + ndoms = 0; + goto done; + } + + /* + * The rest of the code, including the scheduler, can deal with + * dattr==NULL case. No need to abort if alloc fails. + */ dattr = kmalloc(ndoms * sizeof(struct sched_domain_attr), GFP_KERNEL); for (nslot = 0, i = 0; i < csn; i++) { struct cpuset *a = csa[i]; + cpumask_t *dp; int apn = a->pn; - if (apn >= 0) { - cpumask_t *dp = doms + nslot; - - if (nslot == ndoms) { - static int warnings = 10; - if (warnings) { - printk(KERN_WARNING - "rebuild_sched_domains confused:" - " nslot %d, ndoms %d, csn %d, i %d," - " apn %d\n", - nslot, ndoms, csn, i, apn); - warnings--; - } - continue; + if (apn < 0) { + /* Skip completed partitions */ + continue; + } + + dp = doms + nslot; + + if (nslot == ndoms) { + static int warnings = 10; + if (warnings) { + printk(KERN_WARNING + "rebuild_sched_domains confused:" + " nslot %d, ndoms %d, csn %d, i %d," + " apn %d\n", + nslot, ndoms, csn, i, apn); + warnings--; } + continue; + } - cpus_clear(*dp); - if (dattr) - *(dattr + nslot) = SD_ATTR_INIT; - for (j = i; j < csn; j++) { - struct cpuset *b = csa[j]; + cpus_clear(*dp); + if (dattr) + *(dattr + nslot) = SD_ATTR_INIT; + for (j = i; j < csn; j++) { + struct cpuset *b = csa[j]; - if (apn == b->pn) { - cpus_or(*dp, *dp, b->cpus_allowed); - b->pn = -1; - update_domain_attr(dattr, b); - } + if (apn == b->pn) { + cpus_or(*dp, *dp, b->cpus_allowed); + if (dattr) + update_domain_attr_tree(dattr + nslot, b); + + /* Done with this partition */ + b->pn = -1; } - nslot++; } + nslot++; } BUG_ON(nslot != ndoms); -rebuild: - /* Have scheduler rebuild sched domains */ - get_online_cpus(); - partition_sched_domains(ndoms, doms, dattr); - put_online_cpus(); - done: - if (q && !IS_ERR(q)) - kfifo_free(q); kfree(csa); - /* Don't kfree(doms) -- partition_sched_domains() does that. */ - /* Don't kfree(dattr) -- partition_sched_domains() does that. */ + + *domains = doms; + *attributes = dattr; + return ndoms; } -static inline int started_after_time(struct task_struct *t1, - struct timespec *time, - struct task_struct *t2) +/* + * Rebuild scheduler domains. + * + * Call with neither cgroup_mutex held nor within get_online_cpus(). + * Takes both cgroup_mutex and get_online_cpus(). + * + * Cannot be directly called from cpuset code handling changes + * to the cpuset pseudo-filesystem, because it cannot be called + * from code that already holds cgroup_mutex. + */ +static void do_rebuild_sched_domains(struct work_struct *unused) { - int start_diff = timespec_compare(&t1->start_time, time); - if (start_diff > 0) { - return 1; - } else if (start_diff < 0) { - return 0; - } else { - /* - * Arbitrarily, if two processes started at the same - * time, we'll say that the lower pointer value - * started first. Note that t2 may have exited by now - * so this may not be a valid pointer any longer, but - * that's fine - it still serves to distinguish - * between two tasks started (effectively) - * simultaneously. - */ - return t1 > t2; - } + struct sched_domain_attr *attr; + cpumask_t *doms; + int ndoms; + + get_online_cpus(); + + /* Generate domain masks and attrs */ + cgroup_lock(); + ndoms = generate_sched_domains(&doms, &attr); + cgroup_unlock(); + + /* Have scheduler rebuild the domains */ + partition_sched_domains(ndoms, doms, attr); + + put_online_cpus(); +} + +static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains); + +/* + * Rebuild scheduler domains, asynchronously via workqueue. + * + * If the flag 'sched_load_balance' of any cpuset with non-empty + * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset + * which has that flag enabled, or if any cpuset with a non-empty + * 'cpus' is removed, then call this routine to rebuild the + * scheduler's dynamic sched domains. + * + * The rebuild_sched_domains() and partition_sched_domains() + * routines must nest cgroup_lock() inside get_online_cpus(), + * but such cpuset changes as these must nest that locking the + * other way, holding cgroup_lock() for much of the code. + * + * So in order to avoid an ABBA deadlock, the cpuset code handling + * these user changes delegates the actual sched domain rebuilding + * to a separate workqueue thread, which ends up processing the + * above do_rebuild_sched_domains() function. + */ +static void async_rebuild_sched_domains(void) +{ + schedule_work(&rebuild_sched_domains_work); } -static inline int started_after(void *p1, void *p2) +/* + * Accomplishes the same scheduler domain rebuild as the above + * async_rebuild_sched_domains(), however it directly calls the + * rebuild routine synchronously rather than calling it via an + * asynchronous work thread. + * + * This can only be called from code that is not holding + * cgroup_mutex (not nested in a cgroup_lock() call.) + */ +void rebuild_sched_domains(void) { - struct task_struct *t1 = p1; - struct task_struct *t2 = p2; - return started_after_time(t1, &t2->start_time, t2); + do_rebuild_sched_domains(NULL); } /** @@ -766,15 +841,38 @@ static void cpuset_change_cpumask(struct task_struct *tsk, } /** + * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset. + * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed + * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() + * + * Called with cgroup_mutex held + * + * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, + * calling callback functions for each. + * + * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 + * if @heap != NULL. + */ +static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap) +{ + struct cgroup_scanner scan; + + scan.cg = cs->css.cgroup; + scan.test_task = cpuset_test_cpumask; + scan.process_task = cpuset_change_cpumask; + scan.heap = heap; + cgroup_scan_tasks(&scan); +} + +/** * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it * @cs: the cpuset to consider * @buf: buffer of cpu numbers written to this cpuset */ -static int update_cpumask(struct cpuset *cs, char *buf) +static int update_cpumask(struct cpuset *cs, const char *buf) { - struct cpuset trialcs; - struct cgroup_scanner scan; struct ptr_heap heap; + struct cpuset trialcs; int retval; int is_load_balanced; @@ -790,7 +888,6 @@ static int update_cpumask(struct cpuset *cs, char *buf) * that parsing. The validate_change() call ensures that cpusets * with tasks have cpus. */ - buf = strstrip(buf); if (!*buf) { cpus_clear(trialcs.cpus_allowed); } else { @@ -809,7 +906,7 @@ static int update_cpumask(struct cpuset *cs, char *buf) if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed)) return 0; - retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after); + retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); if (retval) return retval; @@ -823,15 +920,12 @@ static int update_cpumask(struct cpuset *cs, char *buf) * Scan tasks in the cpuset, and update the cpumasks of any * that need an update. */ - scan.cg = cs->css.cgroup; - scan.test_task = cpuset_test_cpumask; - scan.process_task = cpuset_change_cpumask; - scan.heap = &heap; - cgroup_scan_tasks(&scan); + update_tasks_cpumask(cs, &heap); + heap_free(&heap); if (is_load_balanced) - rebuild_sched_domains(); + async_rebuild_sched_domains(); return 0; } @@ -884,74 +978,25 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, mutex_unlock(&callback_mutex); } -/* - * Handle user request to change the 'mems' memory placement - * of a cpuset. Needs to validate the request, update the - * cpusets mems_allowed and mems_generation, and for each - * task in the cpuset, rebind any vma mempolicies and if - * the cpuset is marked 'memory_migrate', migrate the tasks - * pages to the new memory. - * - * Call with cgroup_mutex held. May take callback_mutex during call. - * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, - * lock each such tasks mm->mmap_sem, scan its vma's and rebind - * their mempolicies to the cpusets new mems_allowed. - */ - static void *cpuset_being_rebound; -static int update_nodemask(struct cpuset *cs, char *buf) +/** + * update_tasks_nodemask - Update the nodemasks of tasks in the cpuset. + * @cs: the cpuset in which each task's mems_allowed mask needs to be changed + * @oldmem: old mems_allowed of cpuset cs + * + * Called with cgroup_mutex held + * Return 0 if successful, -errno if not. + */ +static int update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem) { - struct cpuset trialcs; - nodemask_t oldmem; struct task_struct *p; struct mm_struct **mmarray; int i, n, ntasks; int migrate; int fudge; - int retval; struct cgroup_iter it; - - /* - * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY]; - * it's read-only - */ - if (cs == &top_cpuset) - return -EACCES; - - trialcs = *cs; - - /* - * An empty mems_allowed is ok iff there are no tasks in the cpuset. - * Since nodelist_parse() fails on an empty mask, we special case - * that parsing. The validate_change() call ensures that cpusets - * with tasks have memory. - */ - buf = strstrip(buf); - if (!*buf) { - nodes_clear(trialcs.mems_allowed); - } else { - retval = nodelist_parse(buf, trialcs.mems_allowed); - if (retval < 0) - goto done; - - if (!nodes_subset(trialcs.mems_allowed, - node_states[N_HIGH_MEMORY])) - return -EINVAL; - } - oldmem = cs->mems_allowed; - if (nodes_equal(oldmem, trialcs.mems_allowed)) { - retval = 0; /* Too easy - nothing to do */ - goto done; - } - retval = validate_change(cs, &trialcs); - if (retval < 0) - goto done; - - mutex_lock(&callback_mutex); - cs->mems_allowed = trialcs.mems_allowed; - cs->mems_generation = cpuset_mems_generation++; - mutex_unlock(&callback_mutex); + int retval; cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ @@ -1018,7 +1063,7 @@ static int update_nodemask(struct cpuset *cs, char *buf) mpol_rebind_mm(mm, &cs->mems_allowed); if (migrate) - cpuset_migrate_mm(mm, &oldmem, &cs->mems_allowed); + cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed); mmput(mm); } @@ -1030,6 +1075,70 @@ done: return retval; } +/* + * Handle user request to change the 'mems' memory placement + * of a cpuset. Needs to validate the request, update the + * cpusets mems_allowed and mems_generation, and for each + * task in the cpuset, rebind any vma mempolicies and if + * the cpuset is marked 'memory_migrate', migrate the tasks + * pages to the new memory. + * + * Call with cgroup_mutex held. May take callback_mutex during call. + * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, + * lock each such tasks mm->mmap_sem, scan its vma's and rebind + * their mempolicies to the cpusets new mems_allowed. + */ +static int update_nodemask(struct cpuset *cs, const char *buf) +{ + struct cpuset trialcs; + nodemask_t oldmem; + int retval; + + /* + * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY]; + * it's read-only + */ + if (cs == &top_cpuset) + return -EACCES; + + trialcs = *cs; + + /* + * An empty mems_allowed is ok iff there are no tasks in the cpuset. + * Since nodelist_parse() fails on an empty mask, we special case + * that parsing. The validate_change() call ensures that cpusets + * with tasks have memory. + */ + if (!*buf) { + nodes_clear(trialcs.mems_allowed); + } else { + retval = nodelist_parse(buf, trialcs.mems_allowed); + if (retval < 0) + goto done; + + if (!nodes_subset(trialcs.mems_allowed, + node_states[N_HIGH_MEMORY])) + return -EINVAL; + } + oldmem = cs->mems_allowed; + if (nodes_equal(oldmem, trialcs.mems_allowed)) { + retval = 0; /* Too easy - nothing to do */ + goto done; + } + retval = validate_change(cs, &trialcs); + if (retval < 0) + goto done; + + mutex_lock(&callback_mutex); + cs->mems_allowed = trialcs.mems_allowed; + cs->mems_generation = cpuset_mems_generation++; + mutex_unlock(&callback_mutex); + + retval = update_tasks_nodemask(cs, &oldmem); +done: + return retval; +} + int current_cpuset_is_being_rebound(void) { return task_cs(current) == cpuset_being_rebound; @@ -1042,7 +1151,8 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) if (val != cs->relax_domain_level) { cs->relax_domain_level = val; - rebuild_sched_domains(); + if (!cpus_empty(cs->cpus_allowed) && is_sched_load_balance(cs)) + async_rebuild_sched_domains(); } return 0; @@ -1083,7 +1193,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, mutex_unlock(&callback_mutex); if (cpus_nonempty && balance_flag_changed) - rebuild_sched_domains(); + async_rebuild_sched_domains(); return 0; } @@ -1194,6 +1304,15 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) return -ENOSPC; + if (tsk->flags & PF_THREAD_BOUND) { + cpumask_t mask; + + mutex_lock(&callback_mutex); + mask = cs->cpus_allowed; + mutex_unlock(&callback_mutex); + if (!cpus_equal(tsk->cpus_allowed, mask)) + return -EINVAL; + } return security_task_setscheduler(tsk, 0, NULL); } @@ -1207,11 +1326,14 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct mm_struct *mm; struct cpuset *cs = cgroup_cs(cont); struct cpuset *oldcs = cgroup_cs(oldcont); + int err; mutex_lock(&callback_mutex); guarantee_online_cpus(cs, &cpus); - set_cpus_allowed_ptr(tsk, &cpus); + err = set_cpus_allowed_ptr(tsk, &cpus); mutex_unlock(&callback_mutex); + if (err) + return; from = oldcs->mems_allowed; to = cs->mems_allowed; @@ -1242,72 +1364,14 @@ typedef enum { FILE_SPREAD_SLAB, } cpuset_filetype_t; -static ssize_t cpuset_common_file_write(struct cgroup *cont, - struct cftype *cft, - struct file *file, - const char __user *userbuf, - size_t nbytes, loff_t *unused_ppos) -{ - struct cpuset *cs = cgroup_cs(cont); - cpuset_filetype_t type = cft->private; - char *buffer; - int retval = 0; - - /* Crude upper limit on largest legitimate cpulist user might write. */ - if (nbytes > 100U + 6 * max(NR_CPUS, MAX_NUMNODES)) - return -E2BIG; - - /* +1 for nul-terminator */ - buffer = kmalloc(nbytes + 1, GFP_KERNEL); - if (!buffer) - return -ENOMEM; - - if (copy_from_user(buffer, userbuf, nbytes)) { - retval = -EFAULT; - goto out1; - } - buffer[nbytes] = 0; /* nul-terminate */ - - cgroup_lock(); - - if (cgroup_is_removed(cont)) { - retval = -ENODEV; - goto out2; - } - - switch (type) { - case FILE_CPULIST: - retval = update_cpumask(cs, buffer); - break; - case FILE_MEMLIST: - retval = update_nodemask(cs, buffer); - break; - default: - retval = -EINVAL; - goto out2; - } - - if (retval == 0) - retval = nbytes; -out2: - cgroup_unlock(); -out1: - kfree(buffer); - return retval; -} - static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) { int retval = 0; struct cpuset *cs = cgroup_cs(cgrp); cpuset_filetype_t type = cft->private; - cgroup_lock(); - - if (cgroup_is_removed(cgrp)) { - cgroup_unlock(); + if (!cgroup_lock_live_group(cgrp)) return -ENODEV; - } switch (type) { case FILE_CPU_EXCLUSIVE: @@ -1353,12 +1417,9 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) struct cpuset *cs = cgroup_cs(cgrp); cpuset_filetype_t type = cft->private; - cgroup_lock(); - - if (cgroup_is_removed(cgrp)) { - cgroup_unlock(); + if (!cgroup_lock_live_group(cgrp)) return -ENODEV; - } + switch (type) { case FILE_SCHED_RELAX_DOMAIN_LEVEL: retval = update_relax_domain_level(cs, val); @@ -1372,6 +1433,32 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) } /* + * Common handling for a write to a "cpus" or "mems" file. + */ +static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, + const char *buf) +{ + int retval = 0; + + if (!cgroup_lock_live_group(cgrp)) + return -ENODEV; + + switch (cft->private) { + case FILE_CPULIST: + retval = update_cpumask(cgroup_cs(cgrp), buf); + break; + case FILE_MEMLIST: + retval = update_nodemask(cgroup_cs(cgrp), buf); + break; + default: + retval = -EINVAL; + break; + } + cgroup_unlock(); + return retval; +} + +/* * These ascii lists should be read in a single call, by using a user * buffer large enough to hold the entire map. If read in smaller * chunks, there is no guarantee of atomicity. Since the display format @@ -1467,6 +1554,9 @@ static u64 cpuset_read_u64(struct cgroup *cont, struct cftype *cft) default: BUG(); } + + /* Unreachable but makes gcc happy */ + return 0; } static s64 cpuset_read_s64(struct cgroup *cont, struct cftype *cft) @@ -1479,6 +1569,9 @@ static s64 cpuset_read_s64(struct cgroup *cont, struct cftype *cft) default: BUG(); } + + /* Unrechable but makes gcc happy */ + return 0; } @@ -1490,14 +1583,16 @@ static struct cftype files[] = { { .name = "cpus", .read = cpuset_common_file_read, - .write = cpuset_common_file_write, + .write_string = cpuset_write_resmask, + .max_write_len = (100U + 6 * NR_CPUS), .private = FILE_CPULIST, }, { .name = "mems", .read = cpuset_common_file_read, - .write = cpuset_common_file_write, + .write_string = cpuset_write_resmask, + .max_write_len = (100U + 6 * MAX_NUMNODES), .private = FILE_MEMLIST, }, @@ -1665,15 +1760,9 @@ static struct cgroup_subsys_state *cpuset_create( } /* - * Locking note on the strange update_flag() call below: - * * If the cpuset being removed has its flag 'sched_load_balance' * enabled, then simulate turning sched_load_balance off, which - * will call rebuild_sched_domains(). The get_online_cpus() - * call in rebuild_sched_domains() must not be made while holding - * callback_mutex. Elsewhere the kernel nests callback_mutex inside - * get_online_cpus() calls. So the reverse nesting would risk an - * ABBA deadlock. + * will call async_rebuild_sched_domains(). */ static void cpuset_destroy(struct cgroup_subsys *ss, struct cgroup *cont) @@ -1692,7 +1781,7 @@ static void cpuset_destroy(struct cgroup_subsys *ss, struct cgroup *cont) struct cgroup_subsys cpuset_subsys = { .name = "cpuset", .create = cpuset_create, - .destroy = cpuset_destroy, + .destroy = cpuset_destroy, .can_attach = cpuset_can_attach, .attach = cpuset_attach, .populate = cpuset_populate, @@ -1778,13 +1867,13 @@ static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) scan.scan.heap = NULL; scan.to = to->css.cgroup; - if (cgroup_scan_tasks((struct cgroup_scanner *)&scan)) + if (cgroup_scan_tasks(&scan.scan)) printk(KERN_ERR "move_member_tasks_to_cpuset: " "cgroup_scan_tasks failed\n"); } /* - * If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs + * If CPU and/or memory hotplug handlers, below, unplug any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, * removing that CPU or node from all cpusets. If this removes the * last CPU or node from a cpuset, then move the tasks in the empty @@ -1832,31 +1921,31 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) * that has tasks along with an empty 'mems'. But if we did see such * a cpuset, we'd handle it just like we do if its 'cpus' was empty. */ -static void scan_for_empty_cpusets(const struct cpuset *root) +static void scan_for_empty_cpusets(struct cpuset *root) { + LIST_HEAD(queue); struct cpuset *cp; /* scans cpusets being updated */ struct cpuset *child; /* scans child cpusets of cp */ - struct list_head queue; struct cgroup *cont; - - INIT_LIST_HEAD(&queue); + nodemask_t oldmems; list_add_tail((struct list_head *)&root->stack_list, &queue); while (!list_empty(&queue)) { - cp = container_of(queue.next, struct cpuset, stack_list); + cp = list_first_entry(&queue, struct cpuset, stack_list); list_del(queue.next); list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { child = cgroup_cs(cont); list_add_tail(&child->stack_list, &queue); } - cont = cp->css.cgroup; /* Continue past cpusets with all cpus, mems online */ if (cpus_subset(cp->cpus_allowed, cpu_online_map) && nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY])) continue; + oldmems = cp->mems_allowed; + /* Remove offline cpus and mems from this cpuset. */ mutex_lock(&callback_mutex); cpus_and(cp->cpus_allowed, cp->cpus_allowed, cpu_online_map); @@ -1868,38 +1957,14 @@ static void scan_for_empty_cpusets(const struct cpuset *root) if (cpus_empty(cp->cpus_allowed) || nodes_empty(cp->mems_allowed)) remove_tasks_in_empty_cpuset(cp); + else { + update_tasks_cpumask(cp, NULL); + update_tasks_nodemask(cp, &oldmems); + } } } /* - * The cpus_allowed and mems_allowed nodemasks in the top_cpuset track - * cpu_online_map and node_states[N_HIGH_MEMORY]. Force the top cpuset to - * track what's online after any CPU or memory node hotplug or unplug event. - * - * Since there are two callers of this routine, one for CPU hotplug - * events and one for memory node hotplug events, we could have coded - * two separate routines here. We code it as a single common routine - * in order to minimize text size. - */ - -static void common_cpu_mem_hotplug_unplug(void) -{ - cgroup_lock(); - - top_cpuset.cpus_allowed = cpu_online_map; - top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; - scan_for_empty_cpusets(&top_cpuset); - - /* - * Scheduler destroys domains on hotplug events. - * Rebuild them based on the current settings. - */ - rebuild_sched_domains(); - - cgroup_unlock(); -} - -/* * The top_cpuset tracks what CPUs and Memory Nodes are online, * period. This is necessary in order to make cpusets transparent * (of no affect) on systems that are actively using CPU hotplug @@ -1907,29 +1972,52 @@ static void common_cpu_mem_hotplug_unplug(void) * * This routine ensures that top_cpuset.cpus_allowed tracks * cpu_online_map on each CPU hotplug (cpuhp) event. + * + * Called within get_online_cpus(). Needs to call cgroup_lock() + * before calling generate_sched_domains(). */ - -static int cpuset_handle_cpuhp(struct notifier_block *unused_nb, +static int cpuset_track_online_cpus(struct notifier_block *unused_nb, unsigned long phase, void *unused_cpu) { - if (phase == CPU_DYING || phase == CPU_DYING_FROZEN) + struct sched_domain_attr *attr; + cpumask_t *doms; + int ndoms; + + switch (phase) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + case CPU_DEAD: + case CPU_DEAD_FROZEN: + break; + + default: return NOTIFY_DONE; + } - common_cpu_mem_hotplug_unplug(); - return 0; + cgroup_lock(); + top_cpuset.cpus_allowed = cpu_online_map; + scan_for_empty_cpusets(&top_cpuset); + ndoms = generate_sched_domains(&doms, &attr); + cgroup_unlock(); + + /* Have scheduler rebuild the domains */ + partition_sched_domains(ndoms, doms, attr); + + return NOTIFY_OK; } #ifdef CONFIG_MEMORY_HOTPLUG /* * Keep top_cpuset.mems_allowed tracking node_states[N_HIGH_MEMORY]. - * Call this routine anytime after you change - * node_states[N_HIGH_MEMORY]. - * See also the previous routine cpuset_handle_cpuhp(). + * Call this routine anytime after node_states[N_HIGH_MEMORY] changes. + * See also the previous routine cpuset_track_online_cpus(). */ - void cpuset_track_online_nodes(void) { - common_cpu_mem_hotplug_unplug(); + cgroup_lock(); + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; + scan_for_empty_cpusets(&top_cpuset); + cgroup_unlock(); } #endif @@ -1944,11 +2032,10 @@ void __init cpuset_init_smp(void) top_cpuset.cpus_allowed = cpu_online_map; top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; - hotcpu_notifier(cpuset_handle_cpuhp, 0); + hotcpu_notifier(cpuset_track_online_cpus, 0); } /** - * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. * @pmask: pointer to cpumask_t variable to receive cpus_allowed set. diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 10e43fd..b3179da 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -145,8 +145,11 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; tmp = d->swapin_delay_total + tsk->delays->swapin_delay; d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; + tmp = d->freepages_delay_total + tsk->delays->freepages_delay; + d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp; d->blkio_count += tsk->delays->blkio_count; d->swapin_count += tsk->delays->swapin_count; + d->freepages_count += tsk->delays->freepages_count; spin_unlock_irqrestore(&tsk->delays->lock, flags); done: @@ -165,3 +168,16 @@ __u64 __delayacct_blkio_ticks(struct task_struct *tsk) return ret; } +void __delayacct_freepages_start(void) +{ + delayacct_start(¤t->delays->freepages_start); +} + +void __delayacct_freepages_end(void) +{ + delayacct_end(¤t->delays->freepages_start, + ¤t->delays->freepages_end, + ¤t->delays->freepages_delay, + ¤t->delays->freepages_count); +} + diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c new file mode 100644 index 0000000..f013a0c --- /dev/null +++ b/kernel/dma-coherent.c @@ -0,0 +1,155 @@ +/* + * Coherent per-device memory handling. + * Borrowed from i386 + */ +#include <linux/kernel.h> +#include <linux/dma-mapping.h> + +struct dma_coherent_mem { + void *virt_base; + u32 device_base; + int size; + int flags; + unsigned long *bitmap; +}; + +int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, + dma_addr_t device_addr, size_t size, int flags) +{ + void __iomem *mem_base = NULL; + int pages = size >> PAGE_SHIFT; + int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); + + if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0) + goto out; + if (!size) + goto out; + if (dev->dma_mem) + goto out; + + /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ + + mem_base = ioremap(bus_addr, size); + if (!mem_base) + goto out; + + dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); + if (!dev->dma_mem) + goto out; + dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + if (!dev->dma_mem->bitmap) + goto free1_out; + + dev->dma_mem->virt_base = mem_base; + dev->dma_mem->device_base = device_addr; + dev->dma_mem->size = pages; + dev->dma_mem->flags = flags; + + if (flags & DMA_MEMORY_MAP) + return DMA_MEMORY_MAP; + + return DMA_MEMORY_IO; + + free1_out: + kfree(dev->dma_mem); + out: + if (mem_base) + iounmap(mem_base); + return 0; +} +EXPORT_SYMBOL(dma_declare_coherent_memory); + +void dma_release_declared_memory(struct device *dev) +{ + struct dma_coherent_mem *mem = dev->dma_mem; + + if (!mem) + return; + dev->dma_mem = NULL; + iounmap(mem->virt_base); + kfree(mem->bitmap); + kfree(mem); +} +EXPORT_SYMBOL(dma_release_declared_memory); + +void *dma_mark_declared_memory_occupied(struct device *dev, + dma_addr_t device_addr, size_t size) +{ + struct dma_coherent_mem *mem = dev->dma_mem; + int pos, err; + + size += device_addr & ~PAGE_MASK; + + if (!mem) + return ERR_PTR(-EINVAL); + + pos = (device_addr - mem->device_base) >> PAGE_SHIFT; + err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); + if (err != 0) + return ERR_PTR(err); + return mem->virt_base + (pos << PAGE_SHIFT); +} +EXPORT_SYMBOL(dma_mark_declared_memory_occupied); + +/** + * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area + * + * @dev: device from which we allocate memory + * @size: size of requested memory area + * @dma_handle: This will be filled with the correct dma handle + * @ret: This pointer will be filled with the virtual address + * to allocated area. + * + * This function should be only called from per-arch dma_alloc_coherent() + * to support allocation from per-device coherent memory pools. + * + * Returns 0 if dma_alloc_coherent should continue with allocating from + * generic memory areas, or !0 if dma_alloc_coherent should return @ret. + */ +int dma_alloc_from_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle, void **ret) +{ + struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + int order = get_order(size); + + if (mem) { + int page = bitmap_find_free_region(mem->bitmap, mem->size, + order); + if (page >= 0) { + *dma_handle = mem->device_base + (page << PAGE_SHIFT); + *ret = mem->virt_base + (page << PAGE_SHIFT); + memset(*ret, 0, size); + } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) + *ret = NULL; + } + return (mem != NULL); +} +EXPORT_SYMBOL(dma_alloc_from_coherent); + +/** + * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool + * @dev: device from which the memory was allocated + * @order: the order of pages allocated + * @vaddr: virtual address of allocated pages + * + * This checks whether the memory was allocated from the per-device + * coherent memory pool and if so, releases that memory. + * + * Returns 1 if we correctly released the memory, or 0 if + * dma_release_coherent() should proceed with releasing memory from + * generic pools. + */ +int dma_release_from_coherent(struct device *dev, int order, void *vaddr) +{ + struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + + if (mem && vaddr >= mem->virt_base && vaddr < + (mem->virt_base + (mem->size << PAGE_SHIFT))) { + int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; + + bitmap_release_region(mem->bitmap, page, order); + return 1; + } + return 0; +} +EXPORT_SYMBOL(dma_release_from_coherent); diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index a9e6bad..0d407e8 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -65,7 +65,7 @@ lookup_exec_domain(u_long personality) goto out; } -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES read_unlock(&exec_domains_lock); request_module("personality-%ld", pers); read_lock(&exec_domains_lock); @@ -168,7 +168,6 @@ __set_personality(u_long personality) current->personality = personality; oep = current_thread_info()->exec_domain; current_thread_info()->exec_domain = ep; - set_fs_altroot(); module_put(oep->module); return 0; diff --git a/kernel/exit.c b/kernel/exit.c index fb8de6c..c8d0485 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -13,6 +13,7 @@ #include <linux/personality.h> #include <linux/tty.h> #include <linux/mnt_namespace.h> +#include <linux/iocontext.h> #include <linux/key.h> #include <linux/security.h> #include <linux/cpu.h> @@ -45,6 +46,7 @@ #include <linux/resource.h> #include <linux/blkdev.h> #include <linux/task_io_accounting_ops.h> +#include <linux/tracehook.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -70,7 +72,7 @@ static void __unhash_process(struct task_struct *p) __get_cpu_var(process_counts)--; } list_del_rcu(&p->thread_group); - remove_parent(p); + list_del_init(&p->sibling); } /* @@ -84,7 +86,6 @@ static void __exit_signal(struct task_struct *tsk) BUG_ON(!sig); BUG_ON(!atomic_read(&sig->count)); - rcu_read_lock(); sighand = rcu_dereference(tsk->sighand); spin_lock(&sighand->siglock); @@ -111,15 +112,16 @@ static void __exit_signal(struct task_struct *tsk) * We won't ever get here for the group leader, since it * will have been the last reference on the signal_struct. */ - sig->utime = cputime_add(sig->utime, tsk->utime); - sig->stime = cputime_add(sig->stime, tsk->stime); - sig->gtime = cputime_add(sig->gtime, tsk->gtime); + sig->utime = cputime_add(sig->utime, task_utime(tsk)); + sig->stime = cputime_add(sig->stime, task_stime(tsk)); + sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; sig->nvcsw += tsk->nvcsw; sig->nivcsw += tsk->nivcsw; sig->inblock += task_io_get_inblock(tsk); sig->oublock += task_io_get_oublock(tsk); + task_io_accounting_add(&sig->ioac, &tsk->ioac); sig->sum_sched_runtime += tsk->se.sum_exec_runtime; sig = NULL; /* Marker for below. */ } @@ -135,7 +137,6 @@ static void __exit_signal(struct task_struct *tsk) tsk->signal = NULL; tsk->sighand = NULL; spin_unlock(&sighand->siglock); - rcu_read_unlock(); __cleanup_sighand(sighand); clear_tsk_thread_flag(tsk,TIF_SIGPENDING); @@ -151,16 +152,17 @@ static void delayed_put_task_struct(struct rcu_head *rhp) put_task_struct(container_of(rhp, struct task_struct, rcu)); } + void release_task(struct task_struct * p) { struct task_struct *leader; int zap_leader; repeat: + tracehook_prepare_release_task(p); atomic_dec(&p->user->processes); proc_flush_task(p); write_lock_irq(&tasklist_lock); - ptrace_unlink(p); - BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); + tracehook_finish_release_task(p); __exit_signal(p); /* @@ -182,6 +184,13 @@ repeat: * that case. */ zap_leader = task_detached(leader); + + /* + * This maintains the invariant that release_task() + * only runs on a task in EXIT_DEAD, just for sanity. + */ + if (zap_leader) + leader->exit_state = EXIT_DEAD; } write_unlock_irq(&tasklist_lock); @@ -314,9 +323,8 @@ static void reparent_to_kthreadd(void) ptrace_unlink(current); /* Reparent to init */ - remove_parent(current); current->real_parent = current->parent = kthreadd_task; - add_parent(current); + list_move_tail(¤t->sibling, ¤t->real_parent->children); /* Set the exit signal to SIGCHLD so we signal init on exit */ current->exit_signal = SIGCHLD; @@ -421,7 +429,7 @@ void daemonize(const char *name, ...) * We don't want to have TIF_FREEZE set if the system-wide hibernation * or suspend transition begins right now. */ - current->flags |= PF_NOFREEZE; + current->flags |= (PF_NOFREEZE | PF_KTHREAD); if (current->nsproxy != &init_nsproxy) { get_nsproxy(&init_nsproxy); @@ -546,8 +554,6 @@ void put_fs_struct(struct fs_struct *fs) if (atomic_dec_and_test(&fs->count)) { path_put(&fs->root); path_put(&fs->pwd); - if (fs->altroot.dentry) - path_put(&fs->altroot); kmem_cache_free(fs_cachep, fs); } } @@ -577,8 +583,6 @@ mm_need_new_owner(struct mm_struct *mm, struct task_struct *p) * If there are other users of the mm and the owner (us) is exiting * we need to find a new owner to take on the responsibility. */ - if (!mm) - return 0; if (atomic_read(&mm->mm_users) <= 1) return 0; if (mm->owner != p) @@ -621,6 +625,16 @@ retry: } while_each_thread(g, c); read_unlock(&tasklist_lock); + /* + * We found no owner yet mm_users > 1: this implies that we are + * most likely racing with swapoff (try_to_unuse()) or /proc or + * ptrace or page migration (get_task_mm()). Mark owner as NULL, + * so that subsystems can understand the callback and take action. + */ + down_write(&mm->mmap_sem); + cgroup_mm_owner_callbacks(mm->owner, NULL); + mm->owner = NULL; + up_write(&mm->mmap_sem); return; assign_new_owner: @@ -655,26 +669,40 @@ assign_new_owner: static void exit_mm(struct task_struct * tsk) { struct mm_struct *mm = tsk->mm; + struct core_state *core_state; mm_release(tsk, mm); if (!mm) return; /* * Serialize with any possible pending coredump. - * We must hold mmap_sem around checking core_waiters + * We must hold mmap_sem around checking core_state * and clearing tsk->mm. The core-inducing thread - * will increment core_waiters for each thread in the + * will increment ->nr_threads for each thread in the * group with ->mm != NULL. */ down_read(&mm->mmap_sem); - if (mm->core_waiters) { + core_state = mm->core_state; + if (core_state) { + struct core_thread self; up_read(&mm->mmap_sem); - down_write(&mm->mmap_sem); - if (!--mm->core_waiters) - complete(mm->core_startup_done); - up_write(&mm->mmap_sem); - wait_for_completion(&mm->core_done); + self.task = tsk; + self.next = xchg(&core_state->dumper.next, &self); + /* + * Implies mb(), the result of xchg() must be visible + * to core_state->dumper. + */ + if (atomic_dec_and_test(&core_state->nr_threads)) + complete(&core_state->startup); + + for (;;) { + set_task_state(tsk, TASK_UNINTERRUPTIBLE); + if (!self.task) /* see coredump_finish() */ + break; + schedule(); + } + __set_task_state(tsk, TASK_RUNNING); down_read(&mm->mmap_sem); } atomic_inc(&mm->mm_count); @@ -691,37 +719,97 @@ static void exit_mm(struct task_struct * tsk) mmput(mm); } -static void -reparent_thread(struct task_struct *p, struct task_struct *father, int traced) +/* + * Return nonzero if @parent's children should reap themselves. + * + * Called with write_lock_irq(&tasklist_lock) held. + */ +static int ignoring_children(struct task_struct *parent) { - if (p->pdeath_signal) - /* We already hold the tasklist_lock here. */ - group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); + int ret; + struct sighand_struct *psig = parent->sighand; + unsigned long flags; + spin_lock_irqsave(&psig->siglock, flags); + ret = (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || + (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT)); + spin_unlock_irqrestore(&psig->siglock, flags); + return ret; +} - /* Move the child from its dying parent to the new one. */ - if (unlikely(traced)) { - /* Preserve ptrace links if someone else is tracing this child. */ - list_del_init(&p->ptrace_list); - if (ptrace_reparented(p)) - list_add(&p->ptrace_list, &p->real_parent->ptrace_children); - } else { - /* If this child is being traced, then we're the one tracing it - * anyway, so let go of it. +/* + * Detach all tasks we were using ptrace on. + * Any that need to be release_task'd are put on the @dead list. + * + * Called with write_lock(&tasklist_lock) held. + */ +static void ptrace_exit(struct task_struct *parent, struct list_head *dead) +{ + struct task_struct *p, *n; + int ign = -1; + + list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) { + __ptrace_unlink(p); + + if (p->exit_state != EXIT_ZOMBIE) + continue; + + /* + * If it's a zombie, our attachedness prevented normal + * parent notification or self-reaping. Do notification + * now if it would have happened earlier. If it should + * reap itself, add it to the @dead list. We can't call + * release_task() here because we already hold tasklist_lock. + * + * If it's our own child, there is no notification to do. + * But if our normal children self-reap, then this child + * was prevented by ptrace and we must reap it now. */ - p->ptrace = 0; - remove_parent(p); - p->parent = p->real_parent; - add_parent(p); + if (!task_detached(p) && thread_group_empty(p)) { + if (!same_thread_group(p->real_parent, parent)) + do_notify_parent(p, p->exit_signal); + else { + if (ign < 0) + ign = ignoring_children(parent); + if (ign) + p->exit_signal = -1; + } + } - if (task_is_traced(p)) { + if (task_detached(p)) { /* - * If it was at a trace stop, turn it into - * a normal stop since it's no longer being - * traced. + * Mark it as in the process of being reaped. */ - ptrace_untrace(p); + p->exit_state = EXIT_DEAD; + list_add(&p->ptrace_entry, dead); } } +} + +/* + * Finish up exit-time ptrace cleanup. + * + * Called without locks. + */ +static void ptrace_exit_finish(struct task_struct *parent, + struct list_head *dead) +{ + struct task_struct *p, *n; + + BUG_ON(!list_empty(&parent->ptraced)); + + list_for_each_entry_safe(p, n, dead, ptrace_entry) { + list_del_init(&p->ptrace_entry); + release_task(p); + } +} + +static void reparent_thread(struct task_struct *p, struct task_struct *father) +{ + if (p->pdeath_signal) + /* We already hold the tasklist_lock here. */ + group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); + + list_move_tail(&p->sibling, &p->real_parent->children); /* If this is a threaded reparent there is no need to * notify anyone anything has happened. @@ -736,7 +824,8 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced) /* If we'd notified the old parent about this child's death, * also notify the new parent. */ - if (!traced && p->exit_state == EXIT_ZOMBIE && + if (!ptrace_reparented(p) && + p->exit_state == EXIT_ZOMBIE && !task_detached(p) && thread_group_empty(p)) do_notify_parent(p, p->exit_signal); @@ -750,75 +839,63 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced) * the child reaper process (ie "init") in our pid * space. */ -static void forget_original_parent(struct task_struct *father) +static struct task_struct *find_new_reaper(struct task_struct *father) { - struct task_struct *p, *n, *reaper = father; - struct list_head ptrace_dead; - - INIT_LIST_HEAD(&ptrace_dead); - - write_lock_irq(&tasklist_lock); - - do { - reaper = next_thread(reaper); - if (reaper == father) { - reaper = task_child_reaper(father); - break; - } - } while (reaper->flags & PF_EXITING); + struct pid_namespace *pid_ns = task_active_pid_ns(father); + struct task_struct *thread; - /* - * There are only two places where our children can be: - * - * - in our child list - * - in our ptraced child list - * - * Search them and reparent children. - */ - list_for_each_entry_safe(p, n, &father->children, sibling) { - int ptrace; - - ptrace = p->ptrace; - - /* if father isn't the real parent, then ptrace must be enabled */ - BUG_ON(father != p->real_parent && !ptrace); + thread = father; + while_each_thread(father, thread) { + if (thread->flags & PF_EXITING) + continue; + if (unlikely(pid_ns->child_reaper == father)) + pid_ns->child_reaper = thread; + return thread; + } - if (father == p->real_parent) { - /* reparent with a reaper, real father it's us */ - p->real_parent = reaper; - reparent_thread(p, father, 0); - } else { - /* reparent ptraced task to its real parent */ - __ptrace_unlink (p); - if (p->exit_state == EXIT_ZOMBIE && !task_detached(p) && - thread_group_empty(p)) - do_notify_parent(p, p->exit_signal); - } + if (unlikely(pid_ns->child_reaper == father)) { + write_unlock_irq(&tasklist_lock); + if (unlikely(pid_ns == &init_pid_ns)) + panic("Attempted to kill init!"); + zap_pid_ns_processes(pid_ns); + write_lock_irq(&tasklist_lock); /* - * if the ptraced child is a detached zombie we must collect - * it before we exit, or it will remain zombie forever since - * we prevented it from self-reap itself while it was being - * traced by us, to be able to see it in wait4. + * We can not clear ->child_reaper or leave it alone. + * There may by stealth EXIT_DEAD tasks on ->children, + * forget_original_parent() must move them somewhere. */ - if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && task_detached(p))) - list_add(&p->ptrace_list, &ptrace_dead); + pid_ns->child_reaper = init_pid_ns.child_reaper; } - list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) { + return pid_ns->child_reaper; +} + +static void forget_original_parent(struct task_struct *father) +{ + struct task_struct *p, *n, *reaper; + LIST_HEAD(ptrace_dead); + + write_lock_irq(&tasklist_lock); + reaper = find_new_reaper(father); + /* + * First clean up ptrace if we were using it. + */ + ptrace_exit(father, &ptrace_dead); + + list_for_each_entry_safe(p, n, &father->children, sibling) { p->real_parent = reaper; - reparent_thread(p, father, 1); + if (p->parent == father) { + BUG_ON(p->ptrace); + p->parent = p->real_parent; + } + reparent_thread(p, father); } write_unlock_irq(&tasklist_lock); BUG_ON(!list_empty(&father->children)); - BUG_ON(!list_empty(&father->ptrace_children)); - - list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_list) { - list_del_init(&p->ptrace_list); - release_task(p); - } + ptrace_exit_finish(father, &ptrace_dead); } /* @@ -827,7 +904,8 @@ static void forget_original_parent(struct task_struct *father) */ static void exit_notify(struct task_struct *tsk, int group_dead) { - int state; + int signal; + void *cookie; /* * This does two things: @@ -864,33 +942,24 @@ static void exit_notify(struct task_struct *tsk, int group_dead) !capable(CAP_KILL)) tsk->exit_signal = SIGCHLD; - /* If something other than our normal parent is ptracing us, then - * send it a SIGCHLD instead of honoring exit_signal. exit_signal - * only has special meaning to our real parent. - */ - if (!task_detached(tsk) && thread_group_empty(tsk)) { - int signal = ptrace_reparented(tsk) ? - SIGCHLD : tsk->exit_signal; - do_notify_parent(tsk, signal); - } else if (tsk->ptrace) { - do_notify_parent(tsk, SIGCHLD); - } + signal = tracehook_notify_death(tsk, &cookie, group_dead); + if (signal >= 0) + signal = do_notify_parent(tsk, signal); - state = EXIT_ZOMBIE; - if (task_detached(tsk) && likely(!tsk->ptrace)) - state = EXIT_DEAD; - tsk->exit_state = state; + tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE; /* mt-exec, de_thread() is waiting for us */ if (thread_group_leader(tsk) && - tsk->signal->notify_count < 0 && - tsk->signal->group_exit_task) + tsk->signal->group_exit_task && + tsk->signal->notify_count < 0) wake_up_process(tsk->signal->group_exit_task); write_unlock_irq(&tasklist_lock); + tracehook_report_death(tsk, signal, cookie, group_dead); + /* If the process is dead, release it - nobody will wait for it */ - if (state == EXIT_DEAD) + if (signal == DEATH_REAP) release_task(tsk); } @@ -919,39 +988,6 @@ static void check_stack_usage(void) static inline void check_stack_usage(void) {} #endif -static inline void exit_child_reaper(struct task_struct *tsk) -{ - if (likely(tsk->group_leader != task_child_reaper(tsk))) - return; - - if (tsk->nsproxy->pid_ns == &init_pid_ns) - panic("Attempted to kill init!"); - - /* - * @tsk is the last thread in the 'cgroup-init' and is exiting. - * Terminate all remaining processes in the namespace and reap them - * before exiting @tsk. - * - * Note that @tsk (last thread of cgroup-init) may not necessarily - * be the child-reaper (i.e main thread of cgroup-init) of the - * namespace i.e the child_reaper may have already exited. - * - * Even after a child_reaper exits, we let it inherit orphaned children, - * because, pid_ns->child_reaper remains valid as long as there is - * at least one living sub-thread in the cgroup init. - - * This living sub-thread of the cgroup-init will be notified when - * a child inherited by the 'child-reaper' exits (do_notify_parent() - * uses __group_send_sig_info()). Further, when reaping child processes, - * do_wait() iterates over children of all living sub threads. - - * i.e even though 'child_reaper' thread is listed as the parent of the - * orphaned children, any living sub-thread in the cgroup-init can - * perform the role of the child_reaper. - */ - zap_pid_ns_processes(tsk->nsproxy->pid_ns); -} - NORET_TYPE void do_exit(long code) { struct task_struct *tsk = current; @@ -966,10 +1002,7 @@ NORET_TYPE void do_exit(long code) if (unlikely(!tsk->pid)) panic("Attempted to kill the idle task!"); - if (unlikely(current->ptrace & PT_TRACE_EXIT)) { - current->ptrace_message = code; - ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); - } + tracehook_report_exit(&code); /* * We're taking recursive faults here in do_exit. Safest is to just @@ -1014,7 +1047,6 @@ NORET_TYPE void do_exit(long code) } group_dead = atomic_dec_and_test(&tsk->signal->live); if (group_dead) { - exit_child_reaper(tsk); hrtimer_cancel(&tsk->signal->real_timer); exit_itimers(tsk->signal); } @@ -1176,13 +1208,6 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options, return 0; } - /* - * Do not consider detached threads that are - * not ptraced: - */ - if (task_detached(p) && !p->ptrace) - return 0; - /* Wait for all children (clone and not) if __WALL is set; * otherwise, wait for clone children *only* if __WCLONE is * set; otherwise, wait for non-clone children *only*. (Note: @@ -1193,14 +1218,10 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options, return 0; err = security_task_wait(p); - if (likely(!err)) - return 1; + if (err) + return err; - if (type != PIDTYPE_PID) - return 0; - /* This child was explicitly requested, abort */ - read_unlock(&tasklist_lock); - return err; + return 1; } static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, @@ -1234,7 +1255,7 @@ static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, * the lock and this task is uninteresting. If we return nonzero, we have * released the lock and the system call should return. */ -static int wait_task_zombie(struct task_struct *p, int noreap, +static int wait_task_zombie(struct task_struct *p, int options, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { @@ -1242,7 +1263,10 @@ static int wait_task_zombie(struct task_struct *p, int noreap, int retval, status, traced; pid_t pid = task_pid_vnr(p); - if (unlikely(noreap)) { + if (!likely(options & WEXITED)) + return 0; + + if (unlikely(options & WNOWAIT)) { uid_t uid = p->uid; int exit_code = p->exit_code; int why, status; @@ -1323,6 +1347,8 @@ static int wait_task_zombie(struct task_struct *p, int noreap, psig->coublock += task_io_get_oublock(p) + sig->oublock + sig->coublock; + task_io_accounting_add(&psig->ioac, &p->ioac); + task_io_accounting_add(&psig->ioac, &sig->ioac); spin_unlock_irq(&p->parent->sighand->siglock); } @@ -1392,21 +1418,24 @@ static int wait_task_zombie(struct task_struct *p, int noreap, * the lock and this task is uninteresting. If we return nonzero, we have * released the lock and the system call should return. */ -static int wait_task_stopped(struct task_struct *p, - int noreap, struct siginfo __user *infop, +static int wait_task_stopped(int ptrace, struct task_struct *p, + int options, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { int retval, exit_code, why; uid_t uid = 0; /* unneeded, required by compiler */ pid_t pid; + if (!(options & WUNTRACED)) + return 0; + exit_code = 0; spin_lock_irq(&p->sighand->siglock); if (unlikely(!task_is_stopped_or_traced(p))) goto unlock_sig; - if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0) + if (!ptrace && p->signal->group_stop_count > 0) /* * A group stop is in progress and this is the group leader. * We won't report until all threads have stopped. @@ -1417,7 +1446,7 @@ static int wait_task_stopped(struct task_struct *p, if (!exit_code) goto unlock_sig; - if (!noreap) + if (!unlikely(options & WNOWAIT)) p->exit_code = 0; uid = p->uid; @@ -1435,10 +1464,10 @@ unlock_sig: */ get_task_struct(p); pid = task_pid_vnr(p); - why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; + why = ptrace ? CLD_TRAPPED : CLD_STOPPED; read_unlock(&tasklist_lock); - if (unlikely(noreap)) + if (unlikely(options & WNOWAIT)) return wait_noreap_copyout(p, pid, uid, why, exit_code, infop, ru); @@ -1472,7 +1501,7 @@ unlock_sig: * the lock and this task is uninteresting. If we return nonzero, we have * released the lock and the system call should return. */ -static int wait_task_continued(struct task_struct *p, int noreap, +static int wait_task_continued(struct task_struct *p, int options, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { @@ -1480,6 +1509,9 @@ static int wait_task_continued(struct task_struct *p, int noreap, pid_t pid; uid_t uid; + if (!unlikely(options & WCONTINUED)) + return 0; + if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) return 0; @@ -1489,7 +1521,7 @@ static int wait_task_continued(struct task_struct *p, int noreap, spin_unlock_irq(&p->sighand->siglock); return 0; } - if (!noreap) + if (!unlikely(options & WNOWAIT)) p->signal->flags &= ~SIGNAL_STOP_CONTINUED; spin_unlock_irq(&p->sighand->siglock); @@ -1515,89 +1547,161 @@ static int wait_task_continued(struct task_struct *p, int noreap, return retval; } +/* + * Consider @p for a wait by @parent. + * + * -ECHILD should be in *@notask_error before the first call. + * Returns nonzero for a final return, when we have unlocked tasklist_lock. + * Returns zero if the search for a child should continue; + * then *@notask_error is 0 if @p is an eligible child, + * or another error from security_task_wait(), or still -ECHILD. + */ +static int wait_consider_task(struct task_struct *parent, int ptrace, + struct task_struct *p, int *notask_error, + enum pid_type type, struct pid *pid, int options, + struct siginfo __user *infop, + int __user *stat_addr, struct rusage __user *ru) +{ + int ret = eligible_child(type, pid, options, p); + if (!ret) + return ret; + + if (unlikely(ret < 0)) { + /* + * If we have not yet seen any eligible child, + * then let this error code replace -ECHILD. + * A permission error will give the user a clue + * to look for security policy problems, rather + * than for mysterious wait bugs. + */ + if (*notask_error) + *notask_error = ret; + } + + if (likely(!ptrace) && unlikely(p->ptrace)) { + /* + * This child is hidden by ptrace. + * We aren't allowed to see it now, but eventually we will. + */ + *notask_error = 0; + return 0; + } + + if (p->exit_state == EXIT_DEAD) + return 0; + + /* + * We don't reap group leaders with subthreads. + */ + if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p)) + return wait_task_zombie(p, options, infop, stat_addr, ru); + + /* + * It's stopped or running now, so it might + * later continue, exit, or stop again. + */ + *notask_error = 0; + + if (task_is_stopped_or_traced(p)) + return wait_task_stopped(ptrace, p, options, + infop, stat_addr, ru); + + return wait_task_continued(p, options, infop, stat_addr, ru); +} + +/* + * Do the work of do_wait() for one thread in the group, @tsk. + * + * -ECHILD should be in *@notask_error before the first call. + * Returns nonzero for a final return, when we have unlocked tasklist_lock. + * Returns zero if the search for a child should continue; then + * *@notask_error is 0 if there were any eligible children, + * or another error from security_task_wait(), or still -ECHILD. + */ +static int do_wait_thread(struct task_struct *tsk, int *notask_error, + enum pid_type type, struct pid *pid, int options, + struct siginfo __user *infop, int __user *stat_addr, + struct rusage __user *ru) +{ + struct task_struct *p; + + list_for_each_entry(p, &tsk->children, sibling) { + /* + * Do not consider detached threads. + */ + if (!task_detached(p)) { + int ret = wait_consider_task(tsk, 0, p, notask_error, + type, pid, options, + infop, stat_addr, ru); + if (ret) + return ret; + } + } + + return 0; +} + +static int ptrace_do_wait(struct task_struct *tsk, int *notask_error, + enum pid_type type, struct pid *pid, int options, + struct siginfo __user *infop, int __user *stat_addr, + struct rusage __user *ru) +{ + struct task_struct *p; + + /* + * Traditionally we see ptrace'd stopped tasks regardless of options. + */ + options |= WUNTRACED; + + list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { + int ret = wait_consider_task(tsk, 1, p, notask_error, + type, pid, options, + infop, stat_addr, ru); + if (ret) + return ret; + } + + return 0; +} + static long do_wait(enum pid_type type, struct pid *pid, int options, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { DECLARE_WAITQUEUE(wait, current); struct task_struct *tsk; - int flag, retval; + int retval; add_wait_queue(¤t->signal->wait_chldexit,&wait); repeat: - /* If there is nothing that can match our critier just get out */ + /* + * If there is nothing that can match our critiera just get out. + * We will clear @retval to zero if we see any child that might later + * match our criteria, even if we are not able to reap it yet. + */ retval = -ECHILD; if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type]))) goto end; - /* - * We will set this flag if we see any child that might later - * match our criteria, even if we are not able to reap it yet. - */ - flag = retval = 0; current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); tsk = current; do { - struct task_struct *p; - - list_for_each_entry(p, &tsk->children, sibling) { - int ret = eligible_child(type, pid, options, p); - if (!ret) - continue; - - if (unlikely(ret < 0)) { - retval = ret; - } else if (task_is_stopped_or_traced(p)) { - /* - * It's stopped now, so it might later - * continue, exit, or stop again. - */ - flag = 1; - if (!(p->ptrace & PT_PTRACED) && - !(options & WUNTRACED)) - continue; - - retval = wait_task_stopped(p, - (options & WNOWAIT), infop, - stat_addr, ru); - } else if (p->exit_state == EXIT_ZOMBIE && - !delay_group_leader(p)) { - /* - * We don't reap group leaders with subthreads. - */ - if (!likely(options & WEXITED)) - continue; - retval = wait_task_zombie(p, - (options & WNOWAIT), infop, - stat_addr, ru); - } else if (p->exit_state != EXIT_DEAD) { - /* - * It's running now, so it might later - * exit, stop, or stop and then continue. - */ - flag = 1; - if (!unlikely(options & WCONTINUED)) - continue; - retval = wait_task_continued(p, - (options & WNOWAIT), infop, - stat_addr, ru); - } - if (retval != 0) /* tasklist_lock released */ - goto end; - } - if (!flag) { - list_for_each_entry(p, &tsk->ptrace_children, - ptrace_list) { - flag = eligible_child(type, pid, options, p); - if (!flag) - continue; - if (likely(flag > 0)) - break; - retval = flag; - goto end; - } + int tsk_result = do_wait_thread(tsk, &retval, + type, pid, options, + infop, stat_addr, ru); + if (!tsk_result) + tsk_result = ptrace_do_wait(tsk, &retval, + type, pid, options, + infop, stat_addr, ru); + if (tsk_result) { + /* + * tasklist_lock is unlocked and we have a final result. + */ + retval = tsk_result; + goto end; } + if (options & __WNOTHREAD) break; tsk = next_thread(tsk); @@ -1605,16 +1709,14 @@ repeat: } while (tsk != current); read_unlock(&tasklist_lock); - if (flag) { - if (options & WNOHANG) - goto end; + if (!retval && !(options & WNOHANG)) { retval = -ERESTARTSYS; - if (signal_pending(current)) - goto end; - schedule(); - goto repeat; + if (!signal_pending(current)) { + schedule(); + goto repeat; + } } - retval = -ECHILD; + end: current->state = TASK_RUNNING; remove_wait_queue(¤t->signal->wait_chldexit,&wait); diff --git a/kernel/fork.c b/kernel/fork.c index d428336..99c5c65 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -23,18 +23,22 @@ #include <linux/sem.h> #include <linux/file.h> #include <linux/fdtable.h> +#include <linux/iocontext.h> #include <linux/key.h> #include <linux/binfmts.h> #include <linux/mman.h> +#include <linux/mmu_notifier.h> #include <linux/fs.h> #include <linux/nsproxy.h> #include <linux/capability.h> #include <linux/cpu.h> #include <linux/cgroup.h> #include <linux/security.h> +#include <linux/hugetlb.h> #include <linux/swap.h> #include <linux/syscalls.h> #include <linux/jiffies.h> +#include <linux/tracehook.h> #include <linux/futex.h> #include <linux/task_io_accounting_ops.h> #include <linux/rcupdate.h> @@ -92,6 +96,23 @@ int nr_processes(void) static struct kmem_cache *task_struct_cachep; #endif +#ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR +static inline struct thread_info *alloc_thread_info(struct task_struct *tsk) +{ +#ifdef CONFIG_DEBUG_STACK_USAGE + gfp_t mask = GFP_KERNEL | __GFP_ZERO; +#else + gfp_t mask = GFP_KERNEL; +#endif + return (struct thread_info *)__get_free_pages(mask, THREAD_SIZE_ORDER); +} + +static inline void free_thread_info(struct thread_info *ti) +{ + free_pages((unsigned long)ti, THREAD_SIZE_ORDER); +} +#endif + /* SLAB cache for signal_struct structures (tsk->signal) */ static struct kmem_cache *signal_cachep; @@ -311,6 +332,14 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) } /* + * Clear hugetlb-related page reserves for children. This only + * affects MAP_PRIVATE mappings. Faults generated by the child + * are not guaranteed to succeed, even if read-only + */ + if (is_vm_hugetlb_page(tmp)) + reset_vma_resv_huge_pages(tmp); + + /* * Link in the new vma and copy the page table entries. */ *pprev = tmp; @@ -378,7 +407,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) INIT_LIST_HEAD(&mm->mmlist); mm->flags = (current->mm) ? current->mm->flags : MMF_DUMP_FILTER_DEFAULT; - mm->core_waiters = 0; + mm->core_state = NULL; mm->nr_ptes = 0; set_mm_counter(mm, file_rss, 0); set_mm_counter(mm, anon_rss, 0); @@ -391,6 +420,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) if (likely(!mm_alloc_pgd(mm))) { mm->def_flags = 0; + mmu_notifier_mm_init(mm); return mm; } @@ -423,6 +453,7 @@ void __mmdrop(struct mm_struct *mm) BUG_ON(mm == &init_mm); mm_free_pgd(mm); destroy_context(mm); + mmu_notifier_mm_destroy(mm); free_mm(mm); } EXPORT_SYMBOL_GPL(__mmdrop); @@ -452,7 +483,7 @@ EXPORT_SYMBOL_GPL(mmput); /** * get_task_mm - acquire a reference to the task's mm * - * Returns %NULL if the task has no mm. Checks PF_BORROWED_MM (meaning + * Returns %NULL if the task has no mm. Checks PF_KTHREAD (meaning * this kernel workthread has transiently adopted a user mm with use_mm, * to do its AIO) is not set and if so returns a reference to it, after * bumping up the use count. User must release the mm via mmput() @@ -465,7 +496,7 @@ struct mm_struct *get_task_mm(struct task_struct *task) task_lock(task); mm = task->mm; if (mm) { - if (task->flags & PF_BORROWED_MM) + if (task->flags & PF_KTHREAD) mm = NULL; else atomic_inc(&mm->mm_users); @@ -634,13 +665,6 @@ static struct fs_struct *__copy_fs_struct(struct fs_struct *old) path_get(&old->root); fs->pwd = old->pwd; path_get(&old->pwd); - if (old->altroot.dentry) { - fs->altroot = old->altroot; - path_get(&old->altroot); - } else { - fs->altroot.mnt = NULL; - fs->altroot.dentry = NULL; - } read_unlock(&old->lock); } return fs; @@ -783,6 +807,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->leader = 0; /* session leadership doesn't inherit */ sig->tty_old_pgrp = NULL; + sig->tty = NULL; sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; sig->gtime = cputime_zero; @@ -790,6 +815,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; + task_io_accounting_init(&sig->ioac); sig->sum_sched_runtime = 0; INIT_LIST_HEAD(&sig->cpu_timers[0]); INIT_LIST_HEAD(&sig->cpu_timers[1]); @@ -818,6 +844,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) void __cleanup_signal(struct signal_struct *sig) { exit_thread_group_keys(sig); + tty_kref_put(sig->tty); kmem_cache_free(signal_cachep, sig); } @@ -837,8 +864,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p) new_flags &= ~PF_SUPERPRIV; new_flags |= PF_FORKNOEXEC; - if (!(clone_flags & CLONE_PTRACE)) - p->ptrace = 0; + new_flags |= PF_STARTING; p->flags = new_flags; clear_freeze_flag(p); } @@ -879,7 +905,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, struct pt_regs *regs, unsigned long stack_size, int __user *child_tidptr, - struct pid *pid) + struct pid *pid, + int trace) { int retval; struct task_struct *p; @@ -914,7 +941,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, rt_mutex_init_task(p); -#ifdef CONFIG_TRACE_IRQFLAGS +#ifdef CONFIG_PROVE_LOCKING DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif @@ -972,13 +999,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->last_switch_timestamp = 0; #endif -#ifdef CONFIG_TASK_XACCT - p->rchar = 0; /* I/O counter: bytes read */ - p->wchar = 0; /* I/O counter: bytes written */ - p->syscr = 0; /* I/O counter: read syscalls */ - p->syscw = 0; /* I/O counter: write syscalls */ -#endif - task_io_accounting_init(p); + task_io_accounting_init(&p->ioac); acct_clear_integrals(p); p->it_virt_expires = cputime_zero; @@ -1085,6 +1106,12 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (clone_flags & CLONE_THREAD) p->tgid = current->tgid; + if (current->nsproxy != p->nsproxy) { + retval = ns_cgroup_clone(p, pid); + if (retval) + goto bad_fork_free_pid; + } + p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; /* * Clear TID on mm_release()? @@ -1129,8 +1156,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, */ p->group_leader = p; INIT_LIST_HEAD(&p->thread_group); - INIT_LIST_HEAD(&p->ptrace_children); - INIT_LIST_HEAD(&p->ptrace_list); /* Now that the task is set up, run cgroup callbacks if * necessary. We need to run them before the task is visible @@ -1161,7 +1186,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->real_parent = current->real_parent; else p->real_parent = current; - p->parent = p->real_parent; spin_lock(¤t->sighand->siglock); @@ -1202,16 +1226,16 @@ static struct task_struct *copy_process(unsigned long clone_flags, } if (likely(p->pid)) { - add_parent(p); - if (unlikely(p->ptrace & PT_PTRACED)) - __ptrace_link(p, current->parent); + list_add_tail(&p->sibling, &p->real_parent->children); + tracehook_finish_clone(p, clone_flags, trace); if (thread_group_leader(p)) { if (clone_flags & CLONE_NEWPID) p->nsproxy->pid_ns->child_reaper = p; p->signal->leader_pid = pid; - p->signal->tty = current->signal->tty; + tty_kref_put(p->signal->tty); + p->signal->tty = tty_kref_get(current->signal->tty); set_task_pgrp(p, task_pgrp_nr(current)); set_task_session(p, task_session_nr(current)); attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); @@ -1289,29 +1313,13 @@ struct task_struct * __cpuinit fork_idle(int cpu) struct pt_regs regs; task = copy_process(CLONE_VM, 0, idle_regs(®s), 0, NULL, - &init_struct_pid); + &init_struct_pid, 0); if (!IS_ERR(task)) init_idle(task, cpu); return task; } -static int fork_traceflag(unsigned clone_flags) -{ - if (clone_flags & CLONE_UNTRACED) - return 0; - else if (clone_flags & CLONE_VFORK) { - if (current->ptrace & PT_TRACE_VFORK) - return PTRACE_EVENT_VFORK; - } else if ((clone_flags & CSIGNAL) != SIGCHLD) { - if (current->ptrace & PT_TRACE_CLONE) - return PTRACE_EVENT_CLONE; - } else if (current->ptrace & PT_TRACE_FORK) - return PTRACE_EVENT_FORK; - - return 0; -} - /* * Ok, this is the main fork-routine. * @@ -1346,14 +1354,14 @@ long do_fork(unsigned long clone_flags, } } - if (unlikely(current->ptrace)) { - trace = fork_traceflag (clone_flags); - if (trace) - clone_flags |= CLONE_PTRACE; - } + /* + * When called from kernel_thread, don't do user tracing stuff. + */ + if (likely(user_mode(regs))) + trace = tracehook_prepare_clone(clone_flags); p = copy_process(clone_flags, stack_start, regs, stack_size, - child_tidptr, NULL); + child_tidptr, NULL, trace); /* * Do this prior waking up the new thread - the thread pointer * might get invalid after that point, if the thread exits quickly. @@ -1371,32 +1379,35 @@ long do_fork(unsigned long clone_flags, init_completion(&vfork); } - if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) { + tracehook_report_clone(trace, regs, clone_flags, nr, p); + + /* + * We set PF_STARTING at creation in case tracing wants to + * use this to distinguish a fully live task from one that + * hasn't gotten to tracehook_report_clone() yet. Now we + * clear it and set the child going. + */ + p->flags &= ~PF_STARTING; + + if (unlikely(clone_flags & CLONE_STOPPED)) { /* * We'll start up with an immediate SIGSTOP. */ sigaddset(&p->pending.signal, SIGSTOP); set_tsk_thread_flag(p, TIF_SIGPENDING); - } - - if (!(clone_flags & CLONE_STOPPED)) - wake_up_new_task(p, clone_flags); - else __set_task_state(p, TASK_STOPPED); - - if (unlikely (trace)) { - current->ptrace_message = nr; - ptrace_notify ((trace << 8) | SIGTRAP); + } else { + wake_up_new_task(p, clone_flags); } + tracehook_report_clone_complete(trace, regs, + clone_flags, nr, p); + if (clone_flags & CLONE_VFORK) { freezer_do_not_count(); wait_for_completion(&vfork); freezer_count(); - if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) { - current->ptrace_message = nr; - ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP); - } + tracehook_report_vfork_done(p, nr); } } else { nr = PTR_ERR(p); @@ -1408,7 +1419,7 @@ long do_fork(unsigned long clone_flags, #define ARCH_MIN_MMSTRUCT_ALIGN 0 #endif -static void sighand_ctor(struct kmem_cache *cachep, void *data) +static void sighand_ctor(void *data) { struct sighand_struct *sighand = data; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5f..cdec83e 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -300,11 +300,10 @@ EXPORT_SYMBOL_GPL(ktime_sub_ns); */ u64 ktime_divns(const ktime_t kt, s64 div) { - u64 dclc, inc, dns; + u64 dclc; int sft = 0; - dclc = dns = ktime_to_ns(kt); - inc = div; + dclc = ktime_to_ns(kt); /* Make sure the divisor is less than 2^32: */ while (div >> 32) { sft++; @@ -623,7 +622,7 @@ static void retrigger_next_event(void *arg) void clock_was_set(void) { /* Retrigger the CPU local events everywhere */ - on_each_cpu(retrigger_next_event, NULL, 0, 1); + on_each_cpu(retrigger_next_event, NULL, 1); } /* @@ -632,8 +631,6 @@ void clock_was_set(void) */ void hres_timers_resume(void) { - WARN_ON_ONCE(num_online_cpus() > 1); - /* Retrigger the CPU local events: */ retrigger_next_event(NULL); } @@ -675,13 +672,14 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, */ BUG_ON(timer->function(timer) != HRTIMER_NORESTART); return 1; - case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: + case HRTIMER_CB_IRQSAFE_PERCPU: + case HRTIMER_CB_IRQSAFE_UNLOCKED: /* * This is solely for the sched tick emulation with * dynamic tick support to ensure that we do not * restart the tick right on the edge and end up with * the tick timer in the softirq ! The calling site - * takes care of this. + * takes care of this. Also used for hrtimer sleeper ! */ debug_hrtimer_deactivate(timer); return 1; @@ -1003,10 +1001,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) */ raise = timer->state == HRTIMER_STATE_PENDING; + /* + * We use preempt_disable to prevent this task from migrating after + * setting up the softirq and raising it. Otherwise, if me migrate + * we will raise the softirq on the wrong CPU. + */ + preempt_disable(); + unlock_hrtimer_base(timer, &flags); if (raise) hrtimer_raise_softirq(); + preempt_enable(); return ret; } @@ -1078,7 +1084,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } EXPORT_SYMBOL_GPL(hrtimer_get_remaining); -#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) +#ifdef CONFIG_NO_HZ /** * hrtimer_get_next_event - get the time until next expiry event * @@ -1240,7 +1246,8 @@ static void __run_hrtimer(struct hrtimer *timer) timer_stats_account_hrtimer(timer); fn = timer->function; - if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) { + if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU || + timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED) { /* * Used for scheduler timers, avoid lock inversion with * rq->lock and tasklist_lock. @@ -1447,7 +1454,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) sl->timer.function = hrtimer_wakeup; sl->task = task; #ifdef CONFIG_HIGH_RES_TIMERS - sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; + sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; #endif } @@ -1586,29 +1593,95 @@ static void __cpuinit init_hrtimers_cpu(int cpu) #ifdef CONFIG_HOTPLUG_CPU -static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, - struct hrtimer_clock_base *new_base) +static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base, + struct hrtimer_clock_base *new_base, int dcpu) { struct hrtimer *timer; struct rb_node *node; + int raise = 0; while ((node = rb_first(&old_base->active))) { timer = rb_entry(node, struct hrtimer, node); BUG_ON(hrtimer_callback_running(timer)); debug_hrtimer_deactivate(timer); - __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0); + + /* + * Should not happen. Per CPU timers should be + * canceled _before_ the migration code is called + */ + if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU) { + __remove_hrtimer(timer, old_base, + HRTIMER_STATE_INACTIVE, 0); + WARN(1, "hrtimer (%p %p)active but cpu %d dead\n", + timer, timer->function, dcpu); + continue; + } + + /* + * Mark it as STATE_MIGRATE not INACTIVE otherwise the + * timer could be seen as !active and just vanish away + * under us on another CPU + */ + __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); timer->base = new_base; /* * Enqueue the timer. Allow reprogramming of the event device */ enqueue_hrtimer(timer, new_base, 1); + +#ifdef CONFIG_HIGH_RES_TIMERS + /* + * Happens with high res enabled when the timer was + * already expired and the callback mode is + * HRTIMER_CB_IRQSAFE_UNLOCKED (hrtimer_sleeper). The + * enqueue code does not move them to the soft irq + * pending list for performance/latency reasons, but + * in the migration state, we need to do that + * otherwise we end up with a stale timer. + */ + if (timer->state == HRTIMER_STATE_MIGRATE) { + timer->state = HRTIMER_STATE_PENDING; + list_add_tail(&timer->cb_entry, + &new_base->cpu_base->cb_pending); + raise = 1; + } +#endif + /* Clear the migration state bit */ + timer->state &= ~HRTIMER_STATE_MIGRATE; } + return raise; } +#ifdef CONFIG_HIGH_RES_TIMERS +static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, + struct hrtimer_cpu_base *new_base) +{ + struct hrtimer *timer; + int raise = 0; + + while (!list_empty(&old_base->cb_pending)) { + timer = list_entry(old_base->cb_pending.next, + struct hrtimer, cb_entry); + + __remove_hrtimer(timer, timer->base, HRTIMER_STATE_PENDING, 0); + timer->base = &new_base->clock_base[timer->base->index]; + list_add_tail(&timer->cb_entry, &new_base->cb_pending); + raise = 1; + } + return raise; +} +#else +static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, + struct hrtimer_cpu_base *new_base) +{ + return 0; +} +#endif + static void migrate_hrtimers(int cpu) { struct hrtimer_cpu_base *old_base, *new_base; - int i; + int i, raise = 0; BUG_ON(cpu_online(cpu)); old_base = &per_cpu(hrtimer_bases, cpu); @@ -1621,14 +1694,21 @@ static void migrate_hrtimers(int cpu) spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - migrate_hrtimer_list(&old_base->clock_base[i], - &new_base->clock_base[i]); + if (migrate_hrtimer_list(&old_base->clock_base[i], + &new_base->clock_base[i], cpu)) + raise = 1; } + if (migrate_hrtimer_pending(old_base, new_base)) + raise = 1; + spin_unlock(&old_base->lock); spin_unlock(&new_base->lock); local_irq_enable(); put_cpu_var(hrtimer_bases); + + if (raise) + hrtimer_raise_softirq(); } #endif /* CONFIG_HOTPLUG_CPU */ @@ -1669,7 +1749,7 @@ void __init hrtimers_init(void) (void *)(long)smp_processor_id()); register_cpu_notifier(&hrtimers_nb); #ifdef CONFIG_HIGH_RES_TIMERS - open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); + open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); #endif } diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 964964b..3cd441e 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -28,8 +28,7 @@ void dynamic_irq_init(unsigned int irq) unsigned long flags; if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); - WARN_ON(1); + WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); return; } @@ -62,8 +61,7 @@ void dynamic_irq_cleanup(unsigned int irq) unsigned long flags; if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); - WARN_ON(1); + WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); return; } @@ -71,9 +69,8 @@ void dynamic_irq_cleanup(unsigned int irq) spin_lock_irqsave(&desc->lock, flags); if (desc->action) { spin_unlock_irqrestore(&desc->lock, flags); - printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n", + WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n", irq); - WARN_ON(1); return; } desc->msi_desc = NULL; @@ -96,8 +93,7 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) unsigned long flags; if (irq >= NR_IRQS) { - printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); - WARN_ON(1); + WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq); return -EINVAL; } diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 46d6611..60c49e3 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -17,6 +17,8 @@ #ifdef CONFIG_SMP +cpumask_t irq_default_affinity = CPU_MASK_ALL; + /** * synchronize_irq - wait for pending IRQ handlers (on other CPUs) * @irq: interrupt number to wait for @@ -87,7 +89,14 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) set_balance_irq_affinity(irq, cpumask); #ifdef CONFIG_GENERIC_PENDING_IRQ - set_pending_irq(irq, cpumask); + if (desc->status & IRQ_MOVE_PCNTXT) { + unsigned long flags; + + spin_lock_irqsave(&desc->lock, flags); + desc->chip->set_affinity(irq, cpumask); + spin_unlock_irqrestore(&desc->lock, flags); + } else + set_pending_irq(irq, cpumask); #else desc->affinity = cpumask; desc->chip->set_affinity(irq, cpumask); @@ -95,6 +104,27 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask) return 0; } +#ifndef CONFIG_AUTO_IRQ_AFFINITY +/* + * Generic version of the affinity autoselector. + */ +int irq_select_affinity(unsigned int irq) +{ + cpumask_t mask; + + if (!irq_can_set_affinity(irq)) + return 0; + + cpus_and(mask, cpu_online_map, irq_default_affinity); + + irq_desc[irq].affinity = mask; + irq_desc[irq].chip->set_affinity(irq, mask); + + set_balance_irq_affinity(irq, mask); + return 0; +} +#endif + #endif /** @@ -154,8 +184,7 @@ static void __enable_irq(struct irq_desc *desc, unsigned int irq) { switch (desc->depth) { case 0: - printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); - WARN_ON(1); + WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); break; case 1: { unsigned int status = desc->status & ~IRQ_DISABLED; @@ -194,6 +223,17 @@ void enable_irq(unsigned int irq) } EXPORT_SYMBOL(enable_irq); +int set_irq_wake_real(unsigned int irq, unsigned int on) +{ + struct irq_desc *desc = irq_desc + irq; + int ret = -ENXIO; + + if (desc->chip->set_wake) + ret = desc->chip->set_wake(irq, on); + + return ret; +} + /** * set_irq_wake - control irq power management wakeup * @irq: interrupt to control @@ -210,30 +250,32 @@ int set_irq_wake(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_desc + irq; unsigned long flags; - int ret = -ENXIO; - int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake; + int ret = 0; /* wakeup-capable irqs can be shared between drivers that * don't need to have the same sleep mode behaviors. */ spin_lock_irqsave(&desc->lock, flags); if (on) { - if (desc->wake_depth++ == 0) - desc->status |= IRQ_WAKEUP; - else - set_wake = NULL; + if (desc->wake_depth++ == 0) { + ret = set_irq_wake_real(irq, on); + if (ret) + desc->wake_depth = 0; + else + desc->status |= IRQ_WAKEUP; + } } else { if (desc->wake_depth == 0) { - printk(KERN_WARNING "Unbalanced IRQ %d " - "wake disable\n", irq); - WARN_ON(1); - } else if (--desc->wake_depth == 0) - desc->status &= ~IRQ_WAKEUP; - else - set_wake = NULL; + WARN(1, "Unbalanced IRQ %d wake disable\n", irq); + } else if (--desc->wake_depth == 0) { + ret = set_irq_wake_real(irq, on); + if (ret) + desc->wake_depth = 1; + else + desc->status &= ~IRQ_WAKEUP; + } } - if (set_wake) - ret = desc->chip->set_wake(irq, on); + spin_unlock_irqrestore(&desc->lock, flags); return ret; } @@ -270,6 +312,31 @@ void compat_irq_chip_set_default_handler(struct irq_desc *desc) desc->handle_irq = NULL; } +static int __irq_set_trigger(struct irq_chip *chip, unsigned int irq, + unsigned long flags) +{ + int ret; + + if (!chip || !chip->set_type) { + /* + * IRQF_TRIGGER_* but the PIC does not support multiple + * flow-types? + */ + pr_warning("No set_type function for IRQ %d (%s)\n", irq, + chip ? (chip->name ? : "unknown") : "unknown"); + return 0; + } + + ret = chip->set_type(irq, flags & IRQF_TRIGGER_MASK); + + if (ret) + pr_err("setting trigger mode %d for irq %u failed (%pF)\n", + (int)(flags & IRQF_TRIGGER_MASK), + irq, chip->set_type); + + return ret; +} + /* * Internal function to register an irqaction - typically used to * allocate special interrupts that are part of the architecture. @@ -281,6 +348,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) const char *old_name = NULL; unsigned long flags; int shared = 0; + int ret; if (irq >= NR_IRQS) return -EINVAL; @@ -338,36 +406,23 @@ int setup_irq(unsigned int irq, struct irqaction *new) shared = 1; } - *p = new; - - /* Exclude IRQ from balancing */ - if (new->flags & IRQF_NOBALANCING) - desc->status |= IRQ_NO_BALANCING; - if (!shared) { irq_chip_set_defaults(desc->chip); -#if defined(CONFIG_IRQ_PER_CPU) - if (new->flags & IRQF_PERCPU) - desc->status |= IRQ_PER_CPU; -#endif - /* Setup the type (level, edge polarity) if configured: */ if (new->flags & IRQF_TRIGGER_MASK) { - if (desc->chip && desc->chip->set_type) - desc->chip->set_type(irq, - new->flags & IRQF_TRIGGER_MASK); - else - /* - * IRQF_TRIGGER_* but the PIC does not support - * multiple flow-types? - */ - printk(KERN_WARNING "No IRQF_TRIGGER set_type " - "function for IRQ %d (%s)\n", irq, - desc->chip ? desc->chip->name : - "unknown"); + ret = __irq_set_trigger(desc->chip, irq, new->flags); + + if (ret) { + spin_unlock_irqrestore(&desc->lock, flags); + return ret; + } } else compat_irq_chip_set_default_handler(desc); +#if defined(CONFIG_IRQ_PER_CPU) + if (new->flags & IRQF_PERCPU) + desc->status |= IRQ_PER_CPU; +#endif desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); @@ -382,7 +437,17 @@ int setup_irq(unsigned int irq, struct irqaction *new) } else /* Undo nested disables: */ desc->depth = 1; + + /* Set default affinity mask once everything is setup */ + irq_select_affinity(irq); } + + *p = new; + + /* Exclude IRQ from balancing */ + if (new->flags & IRQF_NOBALANCING) + desc->status |= IRQ_NO_BALANCING; + /* Reset broken irq detection when installing new handler */ desc->irq_count = 0; desc->irqs_unhandled = 0; @@ -571,8 +636,6 @@ int request_irq(unsigned int irq, irq_handler_t handler, action->next = NULL; action->dev_id = dev_id; - select_smp_affinity(irq); - #ifdef CONFIG_DEBUG_SHIRQ if (irqflags & IRQF_SHARED) { /* diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index c2f2ccb..a09dd29 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -8,6 +8,7 @@ #include <linux/irq.h> #include <linux/proc_fs.h> +#include <linux/seq_file.h> #include <linux/interrupt.h> #include "internals.h" @@ -16,23 +17,18 @@ static struct proc_dir_entry *root_irq_dir; #ifdef CONFIG_SMP -static int irq_affinity_read_proc(char *page, char **start, off_t off, - int count, int *eof, void *data) +static int irq_affinity_proc_show(struct seq_file *m, void *v) { - struct irq_desc *desc = irq_desc + (long)data; + struct irq_desc *desc = irq_desc + (long)m->private; cpumask_t *mask = &desc->affinity; - int len; #ifdef CONFIG_GENERIC_PENDING_IRQ if (desc->status & IRQ_MOVE_PENDING) mask = &desc->pending_mask; #endif - len = cpumask_scnprintf(page, count, *mask); - - if (count - len < 2) - return -EINVAL; - len += sprintf(page + len, "\n"); - return len; + seq_cpumask(m, mask); + seq_putc(m, '\n'); + return 0; } #ifndef is_affinity_mask_valid @@ -40,11 +36,12 @@ static int irq_affinity_read_proc(char *page, char **start, off_t off, #endif int no_irq_affinity; -static int irq_affinity_write_proc(struct file *file, const char __user *buffer, - unsigned long count, void *data) +static ssize_t irq_affinity_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) { - unsigned int irq = (int)(long)data, full_count = count, err; - cpumask_t new_value, tmp; + unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; + cpumask_t new_value; + int err; if (!irq_desc[irq].chip->set_affinity || no_irq_affinity || irq_balancing_disabled(irq)) @@ -62,17 +59,74 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer, * way to make the system unusable accidentally :-) At least * one online CPU still has to be targeted. */ - cpus_and(tmp, new_value, cpu_online_map); - if (cpus_empty(tmp)) + if (!cpus_intersects(new_value, cpu_online_map)) /* Special case for empty set - allow the architecture code to set default SMP affinity. */ - return select_smp_affinity(irq) ? -EINVAL : full_count; + return irq_select_affinity(irq) ? -EINVAL : count; irq_set_affinity(irq, new_value); - return full_count; + return count; +} + +static int irq_affinity_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, irq_affinity_proc_show, PDE(inode)->data); +} + +static const struct file_operations irq_affinity_proc_fops = { + .open = irq_affinity_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = irq_affinity_proc_write, +}; + +static int default_affinity_show(struct seq_file *m, void *v) +{ + seq_cpumask(m, &irq_default_affinity); + seq_putc(m, '\n'); + return 0; +} + +static ssize_t default_affinity_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos) +{ + cpumask_t new_value; + int err; + + err = cpumask_parse_user(buffer, count, new_value); + if (err) + return err; + + if (!is_affinity_mask_valid(new_value)) + return -EINVAL; + + /* + * Do not allow disabling IRQs completely - it's a too easy + * way to make the system unusable accidentally :-) At least + * one online CPU still has to be targeted. + */ + if (!cpus_intersects(new_value, cpu_online_map)) + return -EINVAL; + + irq_default_affinity = new_value; + + return count; +} + +static int default_affinity_open(struct inode *inode, struct file *file) +{ + return single_open(file, default_affinity_show, NULL); } +static const struct file_operations default_affinity_proc_fops = { + .open = default_affinity_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = default_affinity_write, +}; #endif static int irq_spurious_read(char *page, char **start, off_t off, @@ -144,16 +198,9 @@ void register_irq_proc(unsigned int irq) irq_desc[irq].dir = proc_mkdir(name, root_irq_dir); #ifdef CONFIG_SMP - { - /* create /proc/irq/<irq>/smp_affinity */ - entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir); - - if (entry) { - entry->data = (void *)(long)irq; - entry->read_proc = irq_affinity_read_proc; - entry->write_proc = irq_affinity_write_proc; - } - } + /* create /proc/irq/<irq>/smp_affinity */ + proc_create_data("smp_affinity", 0600, irq_desc[irq].dir, + &irq_affinity_proc_fops, (void *)(long)irq); #endif entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir); @@ -171,6 +218,14 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action) remove_proc_entry(action->dir->name, irq_desc[irq].dir); } +void register_default_affinity_proc(void) +{ +#ifdef CONFIG_SMP + proc_create("irq/default_smp_affinity", 0600, NULL, + &default_affinity_proc_fops); +#endif +} + void init_irq_proc(void) { int i; @@ -180,6 +235,8 @@ void init_irq_proc(void) if (!root_irq_dir) return; + register_default_affinity_proc(); + /* * Create entries for all existing IRQs. */ diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 6fc0040..38fc10a 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -176,7 +176,7 @@ static unsigned long get_symbol_pos(unsigned long addr, high = kallsyms_num_syms; while (high - low > 1) { - mid = (low + high) / 2; + mid = low + (high - low) / 2; if (kallsyms_addresses[mid] <= addr) low = mid; else diff --git a/kernel/kexec.c b/kernel/kexec.c index 1c5fcac..aef2653 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -12,7 +12,7 @@ #include <linux/slab.h> #include <linux/fs.h> #include <linux/kexec.h> -#include <linux/spinlock.h> +#include <linux/mutex.h> #include <linux/list.h> #include <linux/highmem.h> #include <linux/syscalls.h> @@ -24,6 +24,12 @@ #include <linux/utsrelease.h> #include <linux/utsname.h> #include <linux/numa.h> +#include <linux/suspend.h> +#include <linux/device.h> +#include <linux/freezer.h> +#include <linux/pm.h> +#include <linux/cpu.h> +#include <linux/console.h> #include <asm/page.h> #include <asm/uaccess.h> @@ -71,7 +77,7 @@ int kexec_should_crash(struct task_struct *p) * * The code for the transition from the current kernel to the * the new kernel is placed in the control_code_buffer, whose size - * is given by KEXEC_CONTROL_CODE_SIZE. In the best case only a single + * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single * page of memory is necessary, but some architectures require more. * Because this memory must be identity mapped in the transition from * virtual to physical addresses it must live in the range @@ -236,12 +242,18 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry, */ result = -ENOMEM; image->control_code_page = kimage_alloc_control_pages(image, - get_order(KEXEC_CONTROL_CODE_SIZE)); + get_order(KEXEC_CONTROL_PAGE_SIZE)); if (!image->control_code_page) { printk(KERN_ERR "Could not allocate control_code_buffer\n"); goto out; } + image->swap_page = kimage_alloc_control_pages(image, 0); + if (!image->swap_page) { + printk(KERN_ERR "Could not allocate swap buffer\n"); + goto out; + } + result = 0; out: if (result == 0) @@ -305,7 +317,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry, */ result = -ENOMEM; image->control_code_page = kimage_alloc_control_pages(image, - get_order(KEXEC_CONTROL_CODE_SIZE)); + get_order(KEXEC_CONTROL_PAGE_SIZE)); if (!image->control_code_page) { printk(KERN_ERR "Could not allocate control_code_buffer\n"); goto out; @@ -589,14 +601,12 @@ static void kimage_free_extra_pages(struct kimage *image) kimage_free_page_list(&image->unuseable_pages); } -static int kimage_terminate(struct kimage *image) +static void kimage_terminate(struct kimage *image) { if (*image->entry != 0) image->entry++; *image->entry = IND_DONE; - - return 0; } #define for_each_kimage_entry(image, ptr, entry) \ @@ -743,8 +753,14 @@ static struct page *kimage_alloc_page(struct kimage *image, *old = addr | (*old & ~PAGE_MASK); /* The old page I have found cannot be a - * destination page, so return it. + * destination page, so return it if it's + * gfp_flags honor the ones passed in. */ + if (!(gfp_mask & __GFP_HIGHMEM) && + PageHighMem(old_page)) { + kimage_free_pages(old_page); + continue; + } addr = old_addr; page = old_page; break; @@ -914,19 +930,14 @@ static int kimage_load_segment(struct kimage *image, */ struct kimage *kexec_image; struct kimage *kexec_crash_image; -/* - * A home grown binary mutex. - * Nothing can wait so this mutex is safe to use - * in interrupt context :) - */ -static int kexec_lock; + +static DEFINE_MUTEX(kexec_mutex); asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, struct kexec_segment __user *segments, unsigned long flags) { struct kimage **dest_image, *image; - int locked; int result; /* We only trust the superuser with rebooting the system. */ @@ -962,8 +973,7 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, * * KISS: always take the mutex. */ - locked = xchg(&kexec_lock, 1); - if (locked) + if (!mutex_trylock(&kexec_mutex)) return -EBUSY; dest_image = &kexec_image; @@ -988,6 +998,8 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, if (result) goto out; + if (flags & KEXEC_PRESERVE_CONTEXT) + image->preserve_context = 1; result = machine_kexec_prepare(image); if (result) goto out; @@ -997,16 +1009,13 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments, if (result) goto out; } - result = kimage_terminate(image); - if (result) - goto out; + kimage_terminate(image); } /* Install the new kernel, and Uninstall the old */ image = xchg(dest_image, image); out: - locked = xchg(&kexec_lock, 0); /* Release the mutex */ - BUG_ON(!locked); + mutex_unlock(&kexec_mutex); kimage_free(image); return result; @@ -1053,10 +1062,7 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry, void crash_kexec(struct pt_regs *regs) { - int locked; - - - /* Take the kexec_lock here to prevent sys_kexec_load + /* Take the kexec_mutex here to prevent sys_kexec_load * running on one cpu from replacing the crash kernel * we are using after a panic on a different cpu. * @@ -1064,8 +1070,7 @@ void crash_kexec(struct pt_regs *regs) * of memory the xchg(&kexec_crash_image) would be * sufficient. But since I reuse the memory... */ - locked = xchg(&kexec_lock, 1); - if (!locked) { + if (mutex_trylock(&kexec_mutex)) { if (kexec_crash_image) { struct pt_regs fixed_regs; crash_setup_regs(&fixed_regs, regs); @@ -1073,8 +1078,7 @@ void crash_kexec(struct pt_regs *regs) machine_crash_shutdown(&fixed_regs); machine_kexec(kexec_crash_image); } - locked = xchg(&kexec_lock, 0); - BUG_ON(!locked); + mutex_unlock(&kexec_mutex); } } @@ -1415,3 +1419,79 @@ static int __init crash_save_vmcoreinfo_init(void) } module_init(crash_save_vmcoreinfo_init) + +/* + * Move into place and start executing a preloaded standalone + * executable. If nothing was preloaded return an error. + */ +int kernel_kexec(void) +{ + int error = 0; + + if (!mutex_trylock(&kexec_mutex)) + return -EBUSY; + if (!kexec_image) { + error = -EINVAL; + goto Unlock; + } + +#ifdef CONFIG_KEXEC_JUMP + if (kexec_image->preserve_context) { + mutex_lock(&pm_mutex); + pm_prepare_console(); + error = freeze_processes(); + if (error) { + error = -EBUSY; + goto Restore_console; + } + suspend_console(); + error = device_suspend(PMSG_FREEZE); + if (error) + goto Resume_console; + error = disable_nonboot_cpus(); + if (error) + goto Resume_devices; + device_pm_lock(); + local_irq_disable(); + /* At this point, device_suspend() has been called, + * but *not* device_power_down(). We *must* + * device_power_down() now. Otherwise, drivers for + * some devices (e.g. interrupt controllers) become + * desynchronized with the actual state of the + * hardware at resume time, and evil weirdness ensues. + */ + error = device_power_down(PMSG_FREEZE); + if (error) + goto Enable_irqs; + } else +#endif + { + kernel_restart_prepare(NULL); + printk(KERN_EMERG "Starting new kernel\n"); + machine_shutdown(); + } + + machine_kexec(kexec_image); + +#ifdef CONFIG_KEXEC_JUMP + if (kexec_image->preserve_context) { + device_power_up(PMSG_RESTORE); + Enable_irqs: + local_irq_enable(); + device_pm_unlock(); + enable_nonboot_cpus(); + Resume_devices: + device_resume(PMSG_RESTORE); + Resume_console: + resume_console(); + thaw_processes(); + Restore_console: + pm_restore_console(); + mutex_unlock(&pm_mutex); + } +#endif + + Unlock: + mutex_unlock(&kexec_mutex); + return error; +} diff --git a/kernel/kgdb.c b/kernel/kgdb.c index 3ec23c3..e4dcfb2 100644 --- a/kernel/kgdb.c +++ b/kernel/kgdb.c @@ -56,12 +56,14 @@ static int kgdb_break_asap; +#define KGDB_MAX_THREAD_QUERY 17 struct kgdb_state { int ex_vector; int signo; int err_code; int cpu; int pass_exception; + unsigned long thr_query; unsigned long threadid; long kgdb_usethreadid; struct pt_regs *linux_regs; @@ -166,13 +168,6 @@ early_param("nokgdbroundup", opt_nokgdbroundup); * Weak aliases for breakpoint management, * can be overriden by architectures when needed: */ -int __weak kgdb_validate_break_address(unsigned long addr) -{ - char tmp_variable[BREAK_INSTR_SIZE]; - - return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE); -} - int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) { int err; @@ -191,6 +186,25 @@ int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) (char *)bundle, BREAK_INSTR_SIZE); } +int __weak kgdb_validate_break_address(unsigned long addr) +{ + char tmp_variable[BREAK_INSTR_SIZE]; + int err; + /* Validate setting the breakpoint and then removing it. In the + * remove fails, the kernel needs to emit a bad message because we + * are deep trouble not being able to put things back the way we + * found them. + */ + err = kgdb_arch_set_breakpoint(addr, tmp_variable); + if (err) + return err; + err = kgdb_arch_remove_breakpoint(addr, tmp_variable); + if (err) + printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " + "memory destroyed at: %lx", addr); + return err; +} + unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) { return instruction_pointer(regs); @@ -433,9 +447,14 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val) { int hex_val; int num = 0; + int negate = 0; *long_val = 0; + if (**ptr == '-') { + negate = 1; + (*ptr)++; + } while (**ptr) { hex_val = hex(**ptr); if (hex_val < 0) @@ -446,6 +465,9 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val) (*ptr)++; } + if (negate) + *long_val = -*long_val; + return num; } @@ -466,7 +488,7 @@ static int write_mem_msg(int binary) if (err) return err; if (CACHE_FLUSH_IS_SAFE) - flush_icache_range(addr, addr + length + 1); + flush_icache_range(addr, addr + length); return 0; } @@ -515,10 +537,16 @@ static void int_to_threadref(unsigned char *id, int value) static struct task_struct *getthread(struct pt_regs *regs, int tid) { /* - * Non-positive TIDs are remapped idle tasks: + * Non-positive TIDs are remapped to the cpu shadow information */ - if (tid <= 0) - return idle_task(-tid); + if (tid == 0 || tid == -1) + tid = -atomic_read(&kgdb_active) - 2; + if (tid < 0) { + if (kgdb_info[-tid - 2].task) + return kgdb_info[-tid - 2].task; + else + return idle_task(-tid - 2); + } /* * find_task_by_pid_ns() does not take the tasklist lock anymore @@ -562,6 +590,7 @@ static void kgdb_wait(struct pt_regs *regs) /* Signal the primary CPU that we are done: */ atomic_set(&cpu_in_kgdb[cpu], 0); + touch_softlockup_watchdog(); clocksource_touch_watchdog(); local_irq_restore(flags); } @@ -725,14 +754,15 @@ setundefined: } /* - * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs: + * Remap normal tasks to their real PID, + * CPU shadow threads are mapped to -CPU - 2 */ static inline int shadow_pid(int realpid) { if (realpid) return realpid; - return -1-raw_smp_processor_id(); + return -raw_smp_processor_id() - 2; } static char gdbmsgbuf[BUFMAX + 1]; @@ -826,7 +856,7 @@ static void gdb_cmd_getregs(struct kgdb_state *ks) local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; } else { local_debuggerinfo = NULL; - for (i = 0; i < NR_CPUS; i++) { + for_each_online_cpu(i) { /* * Try to find the task on some other * or possibly this node if we do not @@ -960,10 +990,13 @@ static int gdb_cmd_reboot(struct kgdb_state *ks) /* Handle the 'q' query packets */ static void gdb_cmd_query(struct kgdb_state *ks) { - struct task_struct *thread; + struct task_struct *g; + struct task_struct *p; unsigned char thref[8]; char *ptr; int i; + int cpu; + int finished = 0; switch (remcom_in_buffer[1]) { case 's': @@ -973,22 +1006,34 @@ static void gdb_cmd_query(struct kgdb_state *ks) break; } - if (remcom_in_buffer[1] == 'f') - ks->threadid = 1; - + i = 0; remcom_out_buffer[0] = 'm'; ptr = remcom_out_buffer + 1; - - for (i = 0; i < 17; ks->threadid++) { - thread = getthread(ks->linux_regs, ks->threadid); - if (thread) { - int_to_threadref(thref, ks->threadid); + if (remcom_in_buffer[1] == 'f') { + /* Each cpu is a shadow thread */ + for_each_online_cpu(cpu) { + ks->thr_query = 0; + int_to_threadref(thref, -cpu - 2); pack_threadid(ptr, thref); ptr += BUF_THREAD_ID_SIZE; *(ptr++) = ','; i++; } } + + do_each_thread(g, p) { + if (i >= ks->thr_query && !finished) { + int_to_threadref(thref, p->pid); + pack_threadid(ptr, thref); + ptr += BUF_THREAD_ID_SIZE; + *(ptr++) = ','; + ks->thr_query++; + if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) + finished = 1; + } + i++; + } while_each_thread(g, p); + *(--ptr) = '\0'; break; @@ -1011,15 +1056,15 @@ static void gdb_cmd_query(struct kgdb_state *ks) error_packet(remcom_out_buffer, -EINVAL); break; } - if (ks->threadid > 0) { + if ((int)ks->threadid > 0) { kgdb_mem2hex(getthread(ks->linux_regs, ks->threadid)->comm, remcom_out_buffer, 16); } else { static char tmpstr[23 + BUF_THREAD_ID_SIZE]; - sprintf(tmpstr, "Shadow task %d for pid 0", - (int)(-ks->threadid-1)); + sprintf(tmpstr, "shadowCPU%d", + (int)(-ks->threadid - 2)); kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); } break; @@ -1388,6 +1433,7 @@ acquirelock: atomic_read(&kgdb_cpu_doing_single_step) != cpu) { atomic_set(&kgdb_active, -1); + touch_softlockup_watchdog(); clocksource_touch_watchdog(); local_irq_restore(flags); @@ -1418,7 +1464,7 @@ acquirelock: * Get the passive CPU lock which will hold all the non-primary * CPU in a spin state while the debugger is active */ - if (!kgdb_single_step || !kgdb_contthread) { + if (!kgdb_single_step) { for (i = 0; i < NR_CPUS; i++) atomic_set(&passive_cpu_wait[i], 1); } @@ -1431,7 +1477,7 @@ acquirelock: #ifdef CONFIG_SMP /* Signal the other CPUs to enter kgdb_wait() */ - if ((!kgdb_single_step || !kgdb_contthread) && kgdb_do_roundup) + if ((!kgdb_single_step) && kgdb_do_roundup) kgdb_roundup_cpus(flags); #endif @@ -1450,7 +1496,7 @@ acquirelock: kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); kgdb_deactivate_sw_breakpoints(); kgdb_single_step = 0; - kgdb_contthread = NULL; + kgdb_contthread = current; exception_level = 0; /* Talk to debugger with gdbserial protocol */ @@ -1464,7 +1510,7 @@ acquirelock: kgdb_info[ks->cpu].task = NULL; atomic_set(&cpu_in_kgdb[ks->cpu], 0); - if (!kgdb_single_step || !kgdb_contthread) { + if (!kgdb_single_step) { for (i = NR_CPUS-1; i >= 0; i--) atomic_set(&passive_cpu_wait[i], 0); /* @@ -1480,6 +1526,7 @@ acquirelock: kgdb_restore: /* Free kgdb_active */ atomic_set(&kgdb_active, -1); + touch_softlockup_watchdog(); clocksource_touch_watchdog(); local_irq_restore(flags); diff --git a/kernel/kmod.c b/kernel/kmod.c index 8df97d3..2456d1a 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -42,7 +42,7 @@ extern int max_threads; static struct workqueue_struct *khelper_wq; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe_path is set via /proc/sys. @@ -352,16 +352,17 @@ static inline void register_pm_notifier_callback(void) {} * @path: path to usermode executable * @argv: arg vector for process * @envp: environment for process + * @gfp_mask: gfp mask for memory allocation * * Returns either %NULL on allocation failure, or a subprocess_info * structure. This should be passed to call_usermodehelper_exec to * exec the process and free the structure. */ -struct subprocess_info *call_usermodehelper_setup(char *path, - char **argv, char **envp) +struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, + char **envp, gfp_t gfp_mask) { struct subprocess_info *sub_info; - sub_info = kzalloc(sizeof(struct subprocess_info), GFP_ATOMIC); + sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); if (!sub_info) goto out; @@ -417,12 +418,12 @@ int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info, { struct file *f; - f = create_write_pipe(); + f = create_write_pipe(0); if (IS_ERR(f)) return PTR_ERR(f); *filp = f; - f = create_read_pipe(f); + f = create_read_pipe(f, 0); if (IS_ERR(f)) { free_write_pipe(*filp); return PTR_ERR(f); @@ -494,7 +495,7 @@ int call_usermodehelper_pipe(char *path, char **argv, char **envp, struct subprocess_info *sub_info; int ret; - sub_info = call_usermodehelper_setup(path, argv, envp); + sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL); if (sub_info == NULL) return -ENOMEM; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d4998f8..75bc2cd 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -62,6 +62,7 @@ addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) #endif +static int kprobes_initialized; static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; @@ -69,8 +70,15 @@ static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; static bool kprobe_enabled; DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ -DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */ static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; +static struct { + spinlock_t lock ____cacheline_aligned; +} kretprobe_table_locks[KPROBE_TABLE_SIZE]; + +static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) +{ + return &(kretprobe_table_locks[hash].lock); +} /* * Normally, functions that we'd want to prohibit kprobes in, are marked @@ -79,7 +87,7 @@ static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; * * For such cases, we now have a blacklist */ -struct kprobe_blackpoint kprobe_blacklist[] = { +static struct kprobe_blackpoint kprobe_blacklist[] = { {"preempt_schedule",}, {NULL} /* Terminator */ }; @@ -368,26 +376,53 @@ void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) return; } -/* Called with kretprobe_lock held */ void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head) { + struct kretprobe *rp = ri->rp; + /* remove rp inst off the rprobe_inst_table */ hlist_del(&ri->hlist); - if (ri->rp) { - /* remove rp inst off the used list */ - hlist_del(&ri->uflist); - /* put rp inst back onto the free list */ - INIT_HLIST_NODE(&ri->uflist); - hlist_add_head(&ri->uflist, &ri->rp->free_instances); + INIT_HLIST_NODE(&ri->hlist); + if (likely(rp)) { + spin_lock(&rp->lock); + hlist_add_head(&ri->hlist, &rp->free_instances); + spin_unlock(&rp->lock); } else /* Unregistering */ hlist_add_head(&ri->hlist, head); } -struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk) +void kretprobe_hash_lock(struct task_struct *tsk, + struct hlist_head **head, unsigned long *flags) { - return &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)]; + unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); + spinlock_t *hlist_lock; + + *head = &kretprobe_inst_table[hash]; + hlist_lock = kretprobe_table_lock_ptr(hash); + spin_lock_irqsave(hlist_lock, *flags); +} + +void kretprobe_table_lock(unsigned long hash, unsigned long *flags) +{ + spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); + spin_lock_irqsave(hlist_lock, *flags); +} + +void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags) +{ + unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); + spinlock_t *hlist_lock; + + hlist_lock = kretprobe_table_lock_ptr(hash); + spin_unlock_irqrestore(hlist_lock, *flags); +} + +void kretprobe_table_unlock(unsigned long hash, unsigned long *flags) +{ + spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); + spin_unlock_irqrestore(hlist_lock, *flags); } /* @@ -401,17 +436,21 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) struct kretprobe_instance *ri; struct hlist_head *head, empty_rp; struct hlist_node *node, *tmp; - unsigned long flags = 0; + unsigned long hash, flags = 0; - INIT_HLIST_HEAD(&empty_rp); - spin_lock_irqsave(&kretprobe_lock, flags); - head = kretprobe_inst_table_head(tk); + if (unlikely(!kprobes_initialized)) + /* Early boot. kretprobe_table_locks not yet initialized. */ + return; + + hash = hash_ptr(tk, KPROBE_HASH_BITS); + head = &kretprobe_inst_table[hash]; + kretprobe_table_lock(hash, &flags); hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task == tk) recycle_rp_inst(ri, &empty_rp); } - spin_unlock_irqrestore(&kretprobe_lock, flags); - + kretprobe_table_unlock(hash, &flags); + INIT_HLIST_HEAD(&empty_rp); hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); @@ -423,24 +462,29 @@ static inline void free_rp_inst(struct kretprobe *rp) struct kretprobe_instance *ri; struct hlist_node *pos, *next; - hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, uflist) { - hlist_del(&ri->uflist); + hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) { + hlist_del(&ri->hlist); kfree(ri); } } static void __kprobes cleanup_rp_inst(struct kretprobe *rp) { - unsigned long flags; + unsigned long flags, hash; struct kretprobe_instance *ri; struct hlist_node *pos, *next; + struct hlist_head *head; + /* No race here */ - spin_lock_irqsave(&kretprobe_lock, flags); - hlist_for_each_entry_safe(ri, pos, next, &rp->used_instances, uflist) { - ri->rp = NULL; - hlist_del(&ri->uflist); + for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) { + kretprobe_table_lock(hash, &flags); + head = &kretprobe_inst_table[hash]; + hlist_for_each_entry_safe(ri, pos, next, head, hlist) { + if (ri->rp == rp) + ri->rp = NULL; + } + kretprobe_table_unlock(hash, &flags); } - spin_unlock_irqrestore(&kretprobe_lock, flags); free_rp_inst(rp); } @@ -831,32 +875,37 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { struct kretprobe *rp = container_of(p, struct kretprobe, kp); - unsigned long flags = 0; + unsigned long hash, flags = 0; + struct kretprobe_instance *ri; /*TODO: consider to only swap the RA after the last pre_handler fired */ - spin_lock_irqsave(&kretprobe_lock, flags); + hash = hash_ptr(current, KPROBE_HASH_BITS); + spin_lock_irqsave(&rp->lock, flags); if (!hlist_empty(&rp->free_instances)) { - struct kretprobe_instance *ri; - ri = hlist_entry(rp->free_instances.first, - struct kretprobe_instance, uflist); + struct kretprobe_instance, hlist); + hlist_del(&ri->hlist); + spin_unlock_irqrestore(&rp->lock, flags); + ri->rp = rp; ri->task = current; if (rp->entry_handler && rp->entry_handler(ri, regs)) { - spin_unlock_irqrestore(&kretprobe_lock, flags); + spin_unlock_irqrestore(&rp->lock, flags); return 0; } arch_prepare_kretprobe(ri, regs); /* XXX(hch): why is there no hlist_move_head? */ - hlist_del(&ri->uflist); - hlist_add_head(&ri->uflist, &ri->rp->used_instances); - hlist_add_head(&ri->hlist, kretprobe_inst_table_head(ri->task)); - } else + INIT_HLIST_NODE(&ri->hlist); + kretprobe_table_lock(hash, &flags); + hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]); + kretprobe_table_unlock(hash, &flags); + } else { rp->nmissed++; - spin_unlock_irqrestore(&kretprobe_lock, flags); + spin_unlock_irqrestore(&rp->lock, flags); + } return 0; } @@ -892,7 +941,7 @@ static int __kprobes __register_kretprobe(struct kretprobe *rp, rp->maxactive = NR_CPUS; #endif } - INIT_HLIST_HEAD(&rp->used_instances); + spin_lock_init(&rp->lock); INIT_HLIST_HEAD(&rp->free_instances); for (i = 0; i < rp->maxactive; i++) { inst = kmalloc(sizeof(struct kretprobe_instance) + @@ -901,8 +950,8 @@ static int __kprobes __register_kretprobe(struct kretprobe *rp, free_rp_inst(rp); return -ENOMEM; } - INIT_HLIST_NODE(&inst->uflist); - hlist_add_head(&inst->uflist, &rp->free_instances); + INIT_HLIST_NODE(&inst->hlist); + hlist_add_head(&inst->hlist, &rp->free_instances); } rp->nmissed = 0; @@ -1009,6 +1058,7 @@ static int __init init_kprobes(void) for (i = 0; i < KPROBE_TABLE_SIZE; i++) { INIT_HLIST_HEAD(&kprobe_table[i]); INIT_HLIST_HEAD(&kretprobe_inst_table[i]); + spin_lock_init(&(kretprobe_table_locks[i].lock)); } /* @@ -1050,6 +1100,7 @@ static int __init init_kprobes(void) err = arch_init_kprobes(); if (!err) err = register_die_notifier(&kprobe_exceptions_nb); + kprobes_initialized = (err == 0); if (!err) init_test_probes(); @@ -1286,13 +1337,8 @@ EXPORT_SYMBOL_GPL(register_jprobe); EXPORT_SYMBOL_GPL(unregister_jprobe); EXPORT_SYMBOL_GPL(register_jprobes); EXPORT_SYMBOL_GPL(unregister_jprobes); -#ifdef CONFIG_KPROBES EXPORT_SYMBOL_GPL(jprobe_return); -#endif - -#ifdef CONFIG_KPROBES EXPORT_SYMBOL_GPL(register_kretprobe); EXPORT_SYMBOL_GPL(unregister_kretprobe); EXPORT_SYMBOL_GPL(register_kretprobes); EXPORT_SYMBOL_GPL(unregister_kretprobes); -#endif diff --git a/kernel/kthread.c b/kernel/kthread.c index bd1b9ea..96cff2f 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -106,7 +106,7 @@ static void create_kthread(struct kthread_create_info *create) */ sched_setscheduler(create->result, SCHED_NORMAL, ¶m); set_user_nice(create->result, KTHREAD_NICE_LEVEL); - set_cpus_allowed(create->result, CPU_MASK_ALL); + set_cpus_allowed_ptr(create->result, CPU_MASK_ALL_PTR); } complete(&create->done); } @@ -176,10 +176,11 @@ void kthread_bind(struct task_struct *k, unsigned int cpu) return; } /* Must have done schedule() in kthread() before we set_task_cpu */ - wait_task_inactive(k); + wait_task_inactive(k, 0); set_task_cpu(k, cpu); k->cpus_allowed = cpumask_of_cpu(cpu); k->rt.nr_cpus_allowed = 1; + k->flags |= PF_THREAD_BOUND; } EXPORT_SYMBOL(kthread_bind); @@ -232,9 +233,9 @@ int kthreadd(void *unused) set_task_comm(tsk, "kthreadd"); ignore_signals(tsk); set_user_nice(tsk, KTHREAD_NICE_LEVEL); - set_cpus_allowed(tsk, CPU_MASK_ALL); + set_cpus_allowed_ptr(tsk, CPU_MASK_ALL_PTR); - current->flags |= PF_NOFREEZE; + current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG; for (;;) { set_current_state(TASK_INTERRUPTIBLE); diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 81a4e4a..dbda475 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -39,6 +39,7 @@ #include <linux/irqflags.h> #include <linux/utsname.h> #include <linux/hash.h> +#include <linux/ftrace.h> #include <asm/sections.h> @@ -81,6 +82,8 @@ static int graph_lock(void) __raw_spin_unlock(&lockdep_lock); return 0; } + /* prevent any recursions within lockdep from causing deadlocks */ + current->lockdep_recursion++; return 1; } @@ -89,6 +92,7 @@ static inline int graph_unlock(void) if (debug_locks && !__raw_spin_is_locked(&lockdep_lock)) return DEBUG_LOCKS_WARN_ON(1); + current->lockdep_recursion--; __raw_spin_unlock(&lockdep_lock); return 0; } @@ -120,6 +124,15 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; unsigned long nr_lock_classes; static struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; +static inline struct lock_class *hlock_class(struct held_lock *hlock) +{ + if (!hlock->class_idx) { + DEBUG_LOCKS_WARN_ON(1); + return NULL; + } + return lock_classes + hlock->class_idx - 1; +} + #ifdef CONFIG_LOCK_STAT static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats); @@ -218,7 +231,7 @@ static void lock_release_holdtime(struct held_lock *hlock) holdtime = sched_clock() - hlock->holdtime_stamp; - stats = get_lock_stats(hlock->class); + stats = get_lock_stats(hlock_class(hlock)); if (hlock->read) lock_time_inc(&stats->read_holdtime, holdtime); else @@ -368,6 +381,19 @@ unsigned int nr_process_chains; unsigned int max_lockdep_depth; unsigned int max_recursion_depth; +static unsigned int lockdep_dependency_gen_id; + +static bool lockdep_dependency_visit(struct lock_class *source, + unsigned int depth) +{ + if (!depth) + lockdep_dependency_gen_id++; + if (source->dep_gen_id == lockdep_dependency_gen_id) + return true; + source->dep_gen_id = lockdep_dependency_gen_id; + return false; +} + #ifdef CONFIG_DEBUG_LOCKDEP /* * We cannot printk in early bootup code. Not even early_printk() @@ -501,7 +527,7 @@ static void print_lockdep_cache(struct lockdep_map *lock) static void print_lock(struct held_lock *hlock) { - print_lock_name(hlock->class); + print_lock_name(hlock_class(hlock)); printk(", at: "); print_ip_sym(hlock->acquire_ip); } @@ -554,6 +580,9 @@ static void print_lock_dependencies(struct lock_class *class, int depth) { struct lock_list *entry; + if (lockdep_dependency_visit(class, depth)) + return; + if (DEBUG_LOCKS_WARN_ON(depth >= 20)) return; @@ -846,11 +875,11 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, if (!entry) return 0; - entry->class = this; - entry->distance = distance; if (!save_trace(&entry->trace)) return 0; + entry->class = this; + entry->distance = distance; /* * Since we never remove from the dependency list, the list can * be walked lockless by other CPUs, it's only allocation @@ -928,7 +957,7 @@ static noinline int print_circular_bug_tail(void) if (debug_locks_silent) return 0; - this.class = check_source->class; + this.class = hlock_class(check_source); if (!save_trace(&this.trace)) return 0; @@ -955,6 +984,67 @@ static int noinline print_infinite_recursion_bug(void) return 0; } +unsigned long __lockdep_count_forward_deps(struct lock_class *class, + unsigned int depth) +{ + struct lock_list *entry; + unsigned long ret = 1; + + if (lockdep_dependency_visit(class, depth)) + return 0; + + /* + * Recurse this class's dependency list: + */ + list_for_each_entry(entry, &class->locks_after, entry) + ret += __lockdep_count_forward_deps(entry->class, depth + 1); + + return ret; +} + +unsigned long lockdep_count_forward_deps(struct lock_class *class) +{ + unsigned long ret, flags; + + local_irq_save(flags); + __raw_spin_lock(&lockdep_lock); + ret = __lockdep_count_forward_deps(class, 0); + __raw_spin_unlock(&lockdep_lock); + local_irq_restore(flags); + + return ret; +} + +unsigned long __lockdep_count_backward_deps(struct lock_class *class, + unsigned int depth) +{ + struct lock_list *entry; + unsigned long ret = 1; + + if (lockdep_dependency_visit(class, depth)) + return 0; + /* + * Recurse this class's dependency list: + */ + list_for_each_entry(entry, &class->locks_before, entry) + ret += __lockdep_count_backward_deps(entry->class, depth + 1); + + return ret; +} + +unsigned long lockdep_count_backward_deps(struct lock_class *class) +{ + unsigned long ret, flags; + + local_irq_save(flags); + __raw_spin_lock(&lockdep_lock); + ret = __lockdep_count_backward_deps(class, 0); + __raw_spin_unlock(&lockdep_lock); + local_irq_restore(flags); + + return ret; +} + /* * Prove that the dependency graph starting at <entry> can not * lead to <target>. Print an error and return 0 if it does. @@ -964,6 +1054,9 @@ check_noncircular(struct lock_class *source, unsigned int depth) { struct lock_list *entry; + if (lockdep_dependency_visit(source, depth)) + return 1; + debug_atomic_inc(&nr_cyclic_check_recursions); if (depth > max_recursion_depth) max_recursion_depth = depth; @@ -973,7 +1066,7 @@ check_noncircular(struct lock_class *source, unsigned int depth) * Check this lock's dependency list: */ list_for_each_entry(entry, &source->locks_after, entry) { - if (entry->class == check_target->class) + if (entry->class == hlock_class(check_target)) return print_circular_bug_header(entry, depth+1); debug_atomic_inc(&nr_cyclic_checks); if (!check_noncircular(entry->class, depth+1)) @@ -982,7 +1075,7 @@ check_noncircular(struct lock_class *source, unsigned int depth) return 1; } -#ifdef CONFIG_TRACE_IRQFLAGS +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) /* * Forwards and backwards subgraph searching, for the purposes of * proving that two subgraphs can be connected by a new dependency @@ -1007,6 +1100,9 @@ find_usage_forwards(struct lock_class *source, unsigned int depth) struct lock_list *entry; int ret; + if (lockdep_dependency_visit(source, depth)) + return 1; + if (depth > max_recursion_depth) max_recursion_depth = depth; if (depth >= RECURSION_LIMIT) @@ -1046,6 +1142,9 @@ find_usage_backwards(struct lock_class *source, unsigned int depth) struct lock_list *entry; int ret; + if (lockdep_dependency_visit(source, depth)) + return 1; + if (!__raw_spin_is_locked(&lockdep_lock)) return DEBUG_LOCKS_WARN_ON(1); @@ -1060,6 +1159,11 @@ find_usage_backwards(struct lock_class *source, unsigned int depth) return 2; } + if (!source && debug_locks_off_graph_unlock()) { + WARN_ON(1); + return 0; + } + /* * Check this lock's dependency list: */ @@ -1099,9 +1203,9 @@ print_bad_irq_dependency(struct task_struct *curr, printk("\nand this task is already holding:\n"); print_lock(prev); printk("which would create a new lock dependency:\n"); - print_lock_name(prev->class); + print_lock_name(hlock_class(prev)); printk(" ->"); - print_lock_name(next->class); + print_lock_name(hlock_class(next)); printk("\n"); printk("\nbut this new dependency connects a %s-irq-safe lock:\n", @@ -1142,12 +1246,12 @@ check_usage(struct task_struct *curr, struct held_lock *prev, find_usage_bit = bit_backwards; /* fills in <backwards_match> */ - ret = find_usage_backwards(prev->class, 0); + ret = find_usage_backwards(hlock_class(prev), 0); if (!ret || ret == 1) return ret; find_usage_bit = bit_forwards; - ret = find_usage_forwards(next->class, 0); + ret = find_usage_forwards(hlock_class(next), 0); if (!ret || ret == 1) return ret; /* ret == 2 */ @@ -1268,18 +1372,32 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, struct lockdep_map *next_instance, int read) { struct held_lock *prev; + struct held_lock *nest = NULL; int i; for (i = 0; i < curr->lockdep_depth; i++) { prev = curr->held_locks + i; - if (prev->class != next->class) + + if (prev->instance == next->nest_lock) + nest = prev; + + if (hlock_class(prev) != hlock_class(next)) continue; + /* * Allow read-after-read recursion of the same * lock class (i.e. read_lock(lock)+read_lock(lock)): */ if ((read == 2) && prev->read) return 2; + + /* + * We're holding the nest_lock, which serializes this lock's + * nesting behaviour. + */ + if (nest) + return 2; + return print_deadlock_bug(curr, prev, next); } return 1; @@ -1325,7 +1443,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, */ check_source = next; check_target = prev; - if (!(check_noncircular(next->class, 0))) + if (!(check_noncircular(hlock_class(next), 0))) return print_circular_bug_tail(); if (!check_prev_add_irq(curr, prev, next)) @@ -1349,8 +1467,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * chains - the second one will be new, but L1 already has * L2 added to its dependency list, due to the first chain.) */ - list_for_each_entry(entry, &prev->class->locks_after, entry) { - if (entry->class == next->class) { + list_for_each_entry(entry, &hlock_class(prev)->locks_after, entry) { + if (entry->class == hlock_class(next)) { if (distance == 1) entry->distance = 1; return 2; @@ -1361,26 +1479,28 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * Ok, all validations passed, add the new lock * to the previous lock's dependency list: */ - ret = add_lock_to_list(prev->class, next->class, - &prev->class->locks_after, next->acquire_ip, distance); + ret = add_lock_to_list(hlock_class(prev), hlock_class(next), + &hlock_class(prev)->locks_after, + next->acquire_ip, distance); if (!ret) return 0; - ret = add_lock_to_list(next->class, prev->class, - &next->class->locks_before, next->acquire_ip, distance); + ret = add_lock_to_list(hlock_class(next), hlock_class(prev), + &hlock_class(next)->locks_before, + next->acquire_ip, distance); if (!ret) return 0; /* * Debugging printouts: */ - if (verbose(prev->class) || verbose(next->class)) { + if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) { graph_unlock(); printk("\n new dependency: "); - print_lock_name(prev->class); + print_lock_name(hlock_class(prev)); printk(" => "); - print_lock_name(next->class); + print_lock_name(hlock_class(next)); printk("\n"); dump_stack(); return graph_lock(); @@ -1458,7 +1578,14 @@ out_bug: } unsigned long nr_lock_chains; -static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS]; +struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS]; +int nr_chain_hlocks; +static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS]; + +struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i) +{ + return lock_classes + chain_hlocks[chain->base + i]; +} /* * Look up a dependency chain. If the key is not present yet then @@ -1466,10 +1593,15 @@ static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS]; * validated. If the key is already hashed, return 0. * (On return with 1 graph_lock is held.) */ -static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class) +static inline int lookup_chain_cache(struct task_struct *curr, + struct held_lock *hlock, + u64 chain_key) { + struct lock_class *class = hlock_class(hlock); struct list_head *hash_head = chainhashentry(chain_key); struct lock_chain *chain; + struct held_lock *hlock_curr, *hlock_next; + int i, j, n, cn; if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return 0; @@ -1517,6 +1649,32 @@ cache_hit: } chain = lock_chains + nr_lock_chains++; chain->chain_key = chain_key; + chain->irq_context = hlock->irq_context; + /* Find the first held_lock of current chain */ + hlock_next = hlock; + for (i = curr->lockdep_depth - 1; i >= 0; i--) { + hlock_curr = curr->held_locks + i; + if (hlock_curr->irq_context != hlock_next->irq_context) + break; + hlock_next = hlock; + } + i++; + chain->depth = curr->lockdep_depth + 1 - i; + cn = nr_chain_hlocks; + while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) { + n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth); + if (n == cn) + break; + cn = n; + } + if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) { + chain->base = cn; + for (j = 0; j < chain->depth - 1; j++, i++) { + int lock_id = curr->held_locks[i].class_idx - 1; + chain_hlocks[chain->base + j] = lock_id; + } + chain_hlocks[chain->base + j] = class - lock_classes; + } list_add_tail_rcu(&chain->entry, hash_head); debug_atomic_inc(&chain_lookup_misses); inc_chains(); @@ -1538,7 +1696,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock, * graph_lock for us) */ if (!hlock->trylock && (hlock->check == 2) && - lookup_chain_cache(chain_key, hlock->class)) { + lookup_chain_cache(curr, hlock, chain_key)) { /* * Check whether last held lock: * @@ -1601,14 +1759,13 @@ static void check_chain_key(struct task_struct *curr) hlock = curr->held_locks + i; if (chain_key != hlock->prev_chain_key) { debug_locks_off(); - printk("hm#1, depth: %u [%u], %016Lx != %016Lx\n", + WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n", curr->lockdep_depth, i, (unsigned long long)chain_key, (unsigned long long)hlock->prev_chain_key); - WARN_ON(1); return; } - id = hlock->class - lock_classes; + id = hlock->class_idx - 1; if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)) return; @@ -1620,11 +1777,10 @@ static void check_chain_key(struct task_struct *curr) } if (chain_key != curr->curr_chain_key) { debug_locks_off(); - printk("hm#2, depth: %u [%u], %016Lx != %016Lx\n", + WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n", curr->lockdep_depth, i, (unsigned long long)chain_key, (unsigned long long)curr->curr_chain_key); - WARN_ON(1); } #endif } @@ -1653,7 +1809,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, print_lock(this); printk("{%s} state was registered at:\n", usage_str[prev_bit]); - print_stack_trace(this->class->usage_traces + prev_bit, 1); + print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1); print_irqtrace_events(curr); printk("\nother info that might help us debug this:\n"); @@ -1672,7 +1828,7 @@ static inline int valid_state(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit) { - if (unlikely(this->class->usage_mask & (1 << bad_bit))) + if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) return print_usage_bug(curr, this, bad_bit, new_bit); return 1; } @@ -1680,7 +1836,7 @@ valid_state(struct task_struct *curr, struct held_lock *this, static int mark_lock(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit); -#ifdef CONFIG_TRACE_IRQFLAGS +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) /* * print irq inversion bug: @@ -1711,7 +1867,7 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other, lockdep_print_held_locks(curr); printk("\nthe first lock's dependencies:\n"); - print_lock_dependencies(this->class, 0); + print_lock_dependencies(hlock_class(this), 0); printk("\nthe second lock's dependencies:\n"); print_lock_dependencies(other, 0); @@ -1734,7 +1890,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this, find_usage_bit = bit; /* fills in <forwards_match> */ - ret = find_usage_forwards(this->class, 0); + ret = find_usage_forwards(hlock_class(this), 0); if (!ret || ret == 1) return ret; @@ -1753,7 +1909,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this, find_usage_bit = bit; /* fills in <backwards_match> */ - ret = find_usage_backwards(this->class, 0); + ret = find_usage_backwards(hlock_class(this), 0); if (!ret || ret == 1) return ret; @@ -1819,7 +1975,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_ENABLED_HARDIRQS_READ, "hard-read")) return 0; #endif - if (hardirq_verbose(this->class)) + if (hardirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_USED_IN_SOFTIRQ: @@ -1844,7 +2000,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_ENABLED_SOFTIRQS_READ, "soft-read")) return 0; #endif - if (softirq_verbose(this->class)) + if (softirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_USED_IN_HARDIRQ_READ: @@ -1857,7 +2013,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, if (!check_usage_forwards(curr, this, LOCK_ENABLED_HARDIRQS, "hard")) return 0; - if (hardirq_verbose(this->class)) + if (hardirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_USED_IN_SOFTIRQ_READ: @@ -1870,7 +2026,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, if (!check_usage_forwards(curr, this, LOCK_ENABLED_SOFTIRQS, "soft")) return 0; - if (softirq_verbose(this->class)) + if (softirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_ENABLED_HARDIRQS: @@ -1896,7 +2052,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_USED_IN_HARDIRQ_READ, "hard-read")) return 0; #endif - if (hardirq_verbose(this->class)) + if (hardirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_ENABLED_SOFTIRQS: @@ -1922,7 +2078,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_USED_IN_SOFTIRQ_READ, "soft-read")) return 0; #endif - if (softirq_verbose(this->class)) + if (softirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_ENABLED_HARDIRQS_READ: @@ -1937,7 +2093,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_USED_IN_HARDIRQ, "hard")) return 0; #endif - if (hardirq_verbose(this->class)) + if (hardirq_verbose(hlock_class(this))) ret = 2; break; case LOCK_ENABLED_SOFTIRQS_READ: @@ -1952,7 +2108,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, LOCK_USED_IN_SOFTIRQ, "soft")) return 0; #endif - if (softirq_verbose(this->class)) + if (softirq_verbose(hlock_class(this))) ret = 2; break; default: @@ -2013,11 +2169,13 @@ void early_boot_irqs_on(void) /* * Hardirqs will be enabled: */ -void trace_hardirqs_on(void) +void trace_hardirqs_on_caller(unsigned long a0) { struct task_struct *curr = current; unsigned long ip; + time_hardirqs_on(CALLER_ADDR0, a0); + if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2055,16 +2213,23 @@ void trace_hardirqs_on(void) curr->hardirq_enable_event = ++curr->irq_events; debug_atomic_inc(&hardirqs_on_events); } +EXPORT_SYMBOL(trace_hardirqs_on_caller); +void trace_hardirqs_on(void) +{ + trace_hardirqs_on_caller(CALLER_ADDR0); +} EXPORT_SYMBOL(trace_hardirqs_on); /* * Hardirqs were disabled: */ -void trace_hardirqs_off(void) +void trace_hardirqs_off_caller(unsigned long a0) { struct task_struct *curr = current; + time_hardirqs_off(CALLER_ADDR0, a0); + if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2082,7 +2247,12 @@ void trace_hardirqs_off(void) } else debug_atomic_inc(&redundant_hardirqs_off); } +EXPORT_SYMBOL(trace_hardirqs_off_caller); +void trace_hardirqs_off(void) +{ + trace_hardirqs_off_caller(CALLER_ADDR0); +} EXPORT_SYMBOL(trace_hardirqs_off); /* @@ -2246,7 +2416,7 @@ static inline int separate_irq_context(struct task_struct *curr, * Mark a lock with a usage bit, and validate the state transition: */ static int mark_lock(struct task_struct *curr, struct held_lock *this, - enum lock_usage_bit new_bit) + enum lock_usage_bit new_bit) { unsigned int new_mask = 1 << new_bit, ret = 1; @@ -2254,7 +2424,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, * If already set then do not dirty the cacheline, * nor do any checks: */ - if (likely(this->class->usage_mask & new_mask)) + if (likely(hlock_class(this)->usage_mask & new_mask)) return 1; if (!graph_lock()) @@ -2262,14 +2432,14 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, /* * Make sure we didnt race: */ - if (unlikely(this->class->usage_mask & new_mask)) { + if (unlikely(hlock_class(this)->usage_mask & new_mask)) { graph_unlock(); return 1; } - this->class->usage_mask |= new_mask; + hlock_class(this)->usage_mask |= new_mask; - if (!save_trace(this->class->usage_traces + new_bit)) + if (!save_trace(hlock_class(this)->usage_traces + new_bit)) return 0; switch (new_bit) { @@ -2349,7 +2519,7 @@ EXPORT_SYMBOL_GPL(lockdep_init_map); */ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, int trylock, int read, int check, int hardirqs_off, - unsigned long ip) + struct lockdep_map *nest_lock, unsigned long ip) { struct task_struct *curr = current; struct lock_class *class = NULL; @@ -2403,14 +2573,16 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, return 0; hlock = curr->held_locks + depth; - - hlock->class = class; + if (DEBUG_LOCKS_WARN_ON(!class)) + return 0; + hlock->class_idx = class - lock_classes + 1; hlock->acquire_ip = ip; hlock->instance = lock; + hlock->nest_lock = nest_lock; hlock->trylock = trylock; hlock->read = read; hlock->check = check; - hlock->hardirqs_off = hardirqs_off; + hlock->hardirqs_off = !!hardirqs_off; #ifdef CONFIG_LOCK_STAT hlock->waittime_stamp = 0; hlock->holdtime_stamp = sched_clock(); @@ -2518,6 +2690,55 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock, return 1; } +static int +__lock_set_subclass(struct lockdep_map *lock, + unsigned int subclass, unsigned long ip) +{ + struct task_struct *curr = current; + struct held_lock *hlock, *prev_hlock; + struct lock_class *class; + unsigned int depth; + int i; + + depth = curr->lockdep_depth; + if (DEBUG_LOCKS_WARN_ON(!depth)) + return 0; + + prev_hlock = NULL; + for (i = depth-1; i >= 0; i--) { + hlock = curr->held_locks + i; + /* + * We must not cross into another context: + */ + if (prev_hlock && prev_hlock->irq_context != hlock->irq_context) + break; + if (hlock->instance == lock) + goto found_it; + prev_hlock = hlock; + } + return print_unlock_inbalance_bug(curr, lock, ip); + +found_it: + class = register_lock_class(lock, subclass, 0); + hlock->class_idx = class - lock_classes + 1; + + curr->lockdep_depth = i; + curr->curr_chain_key = hlock->prev_chain_key; + + for (; i < depth; i++) { + hlock = curr->held_locks + i; + if (!__lock_acquire(hlock->instance, + hlock_class(hlock)->subclass, hlock->trylock, + hlock->read, hlock->check, hlock->hardirqs_off, + hlock->nest_lock, hlock->acquire_ip)) + return 0; + } + + if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth)) + return 0; + return 1; +} + /* * Remove the lock to the list of currently held locks in a * potentially non-nested (out of order) manner. This is a @@ -2568,9 +2789,9 @@ found_it: for (i++; i < depth; i++) { hlock = curr->held_locks + i; if (!__lock_acquire(hlock->instance, - hlock->class->subclass, hlock->trylock, + hlock_class(hlock)->subclass, hlock->trylock, hlock->read, hlock->check, hlock->hardirqs_off, - hlock->acquire_ip)) + hlock->nest_lock, hlock->acquire_ip)) return 0; } @@ -2613,7 +2834,7 @@ static int lock_release_nested(struct task_struct *curr, #ifdef CONFIG_DEBUG_LOCKDEP hlock->prev_chain_key = 0; - hlock->class = NULL; + hlock->class_idx = 0; hlock->acquire_ip = 0; hlock->irq_context = 0; #endif @@ -2650,7 +2871,8 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip) */ static void check_flags(unsigned long flags) { -#if defined(CONFIG_DEBUG_LOCKDEP) && defined(CONFIG_TRACE_IRQFLAGS) +#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \ + defined(CONFIG_TRACE_IRQFLAGS) if (!debug_locks) return; @@ -2681,18 +2903,36 @@ static void check_flags(unsigned long flags) #endif } +void +lock_set_subclass(struct lockdep_map *lock, + unsigned int subclass, unsigned long ip) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + current->lockdep_recursion = 1; + check_flags(flags); + if (__lock_set_subclass(lock, subclass, ip)) + check_chain_key(current); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} + +EXPORT_SYMBOL_GPL(lock_set_subclass); + /* * We are not always called with irqs disabled - do that here, * and also avoid lockdep recursion: */ void lock_acquire(struct lockdep_map *lock, unsigned int subclass, - int trylock, int read, int check, unsigned long ip) + int trylock, int read, int check, + struct lockdep_map *nest_lock, unsigned long ip) { unsigned long flags; - if (unlikely(!lock_stat && !prove_locking)) - return; - if (unlikely(current->lockdep_recursion)) return; @@ -2701,20 +2941,18 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass, current->lockdep_recursion = 1; __lock_acquire(lock, subclass, trylock, read, check, - irqs_disabled_flags(flags), ip); + irqs_disabled_flags(flags), nest_lock, ip); current->lockdep_recursion = 0; raw_local_irq_restore(flags); } EXPORT_SYMBOL_GPL(lock_acquire); -void lock_release(struct lockdep_map *lock, int nested, unsigned long ip) +void lock_release(struct lockdep_map *lock, int nested, + unsigned long ip) { unsigned long flags; - if (unlikely(!lock_stat && !prove_locking)) - return; - if (unlikely(current->lockdep_recursion)) return; @@ -2787,11 +3025,11 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip) found_it: hlock->waittime_stamp = sched_clock(); - point = lock_contention_point(hlock->class, ip); + point = lock_contention_point(hlock_class(hlock), ip); - stats = get_lock_stats(hlock->class); + stats = get_lock_stats(hlock_class(hlock)); if (point < ARRAY_SIZE(stats->contention_point)) - stats->contention_point[i]++; + stats->contention_point[point]++; if (lock->cpu != smp_processor_id()) stats->bounces[bounce_contended + !!hlock->read]++; put_lock_stats(stats); @@ -2835,7 +3073,7 @@ found_it: hlock->holdtime_stamp = now; } - stats = get_lock_stats(hlock->class); + stats = get_lock_stats(hlock_class(hlock)); if (waittime) { if (hlock->read) lock_time_inc(&stats->read_waittime, waittime); @@ -2930,6 +3168,7 @@ static void zap_class(struct lock_class *class) list_del_rcu(&class->hash_entry); list_del_rcu(&class->lock_entry); + class->key = NULL; } static inline int within(const void *addr, void *start, unsigned long size) diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index 8ce09bc..56b1969 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h @@ -17,12 +17,11 @@ */ #define MAX_LOCKDEP_ENTRIES 8192UL -#define MAX_LOCKDEP_KEYS_BITS 11 -#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS) - #define MAX_LOCKDEP_CHAINS_BITS 14 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) +#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5) + /* * Stack-trace: tightly packed array of stack backtrace * addresses. Protected by the hash_lock. @@ -30,15 +29,19 @@ #define MAX_STACK_TRACE_ENTRIES 262144UL extern struct list_head all_lock_classes; +extern struct lock_chain lock_chains[]; extern void get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4); extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); +struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); + extern unsigned long nr_lock_classes; extern unsigned long nr_list_entries; extern unsigned long nr_lock_chains; +extern int nr_chain_hlocks; extern unsigned long nr_stack_trace_entries; extern unsigned int nr_hardirq_chains; @@ -47,6 +50,22 @@ extern unsigned int nr_process_chains; extern unsigned int max_lockdep_depth; extern unsigned int max_recursion_depth; +#ifdef CONFIG_PROVE_LOCKING +extern unsigned long lockdep_count_forward_deps(struct lock_class *); +extern unsigned long lockdep_count_backward_deps(struct lock_class *); +#else +static inline unsigned long +lockdep_count_forward_deps(struct lock_class *class) +{ + return 0; +} +static inline unsigned long +lockdep_count_backward_deps(struct lock_class *class) +{ + return 0; +} +#endif + #ifdef CONFIG_DEBUG_LOCKDEP /* * Various lockdep statistics: diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index dc5d296..20dbcbf 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -63,34 +63,6 @@ static void l_stop(struct seq_file *m, void *v) { } -static unsigned long count_forward_deps(struct lock_class *class) -{ - struct lock_list *entry; - unsigned long ret = 1; - - /* - * Recurse this class's dependency list: - */ - list_for_each_entry(entry, &class->locks_after, entry) - ret += count_forward_deps(entry->class); - - return ret; -} - -static unsigned long count_backward_deps(struct lock_class *class) -{ - struct lock_list *entry; - unsigned long ret = 1; - - /* - * Recurse this class's dependency list: - */ - list_for_each_entry(entry, &class->locks_before, entry) - ret += count_backward_deps(entry->class); - - return ret; -} - static void print_name(struct seq_file *m, struct lock_class *class) { char str[128]; @@ -110,7 +82,6 @@ static void print_name(struct seq_file *m, struct lock_class *class) static int l_show(struct seq_file *m, void *v) { - unsigned long nr_forward_deps, nr_backward_deps; struct lock_class *class = v; struct lock_list *entry; char c1, c2, c3, c4; @@ -124,11 +95,10 @@ static int l_show(struct seq_file *m, void *v) #ifdef CONFIG_DEBUG_LOCKDEP seq_printf(m, " OPS:%8ld", class->ops); #endif - nr_forward_deps = count_forward_deps(class); - seq_printf(m, " FD:%5ld", nr_forward_deps); - - nr_backward_deps = count_backward_deps(class); - seq_printf(m, " BD:%5ld", nr_backward_deps); +#ifdef CONFIG_PROVE_LOCKING + seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class)); + seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); +#endif get_usage_chars(class, &c1, &c2, &c3, &c4); seq_printf(m, " %c%c%c%c", c1, c2, c3, c4); @@ -139,7 +109,7 @@ static int l_show(struct seq_file *m, void *v) list_for_each_entry(entry, &class->locks_after, entry) { if (entry->distance == 1) { - seq_printf(m, " -> [%p] ", entry->class); + seq_printf(m, " -> [%p] ", entry->class->key); print_name(m, entry->class); seq_puts(m, "\n"); } @@ -178,6 +148,98 @@ static const struct file_operations proc_lockdep_operations = { .release = seq_release, }; +#ifdef CONFIG_PROVE_LOCKING +static void *lc_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct lock_chain *chain; + + (*pos)++; + + if (v == SEQ_START_TOKEN) + chain = m->private; + else { + chain = v; + + if (*pos < nr_lock_chains) + chain = lock_chains + *pos; + else + chain = NULL; + } + + return chain; +} + +static void *lc_start(struct seq_file *m, loff_t *pos) +{ + if (*pos == 0) + return SEQ_START_TOKEN; + + if (*pos < nr_lock_chains) + return lock_chains + *pos; + + return NULL; +} + +static void lc_stop(struct seq_file *m, void *v) +{ +} + +static int lc_show(struct seq_file *m, void *v) +{ + struct lock_chain *chain = v; + struct lock_class *class; + int i; + + if (v == SEQ_START_TOKEN) { + seq_printf(m, "all lock chains:\n"); + return 0; + } + + seq_printf(m, "irq_context: %d\n", chain->irq_context); + + for (i = 0; i < chain->depth; i++) { + class = lock_chain_get_class(chain, i); + if (!class->key) + continue; + + seq_printf(m, "[%p] ", class->key); + print_name(m, class); + seq_puts(m, "\n"); + } + seq_puts(m, "\n"); + + return 0; +} + +static const struct seq_operations lockdep_chains_ops = { + .start = lc_start, + .next = lc_next, + .stop = lc_stop, + .show = lc_show, +}; + +static int lockdep_chains_open(struct inode *inode, struct file *file) +{ + int res = seq_open(file, &lockdep_chains_ops); + if (!res) { + struct seq_file *m = file->private_data; + + if (nr_lock_chains) + m->private = lock_chains; + else + m->private = NULL; + } + return res; +} + +static const struct file_operations proc_lockdep_chains_operations = { + .open = lockdep_chains_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif /* CONFIG_PROVE_LOCKING */ + static void lockdep_stats_debug_show(struct seq_file *m) { #ifdef CONFIG_DEBUG_LOCKDEP @@ -261,7 +323,9 @@ static int lockdep_stats_show(struct seq_file *m, void *v) if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ) nr_hardirq_read_unsafe++; - sum_forward_deps += count_forward_deps(class); +#ifdef CONFIG_PROVE_LOCKING + sum_forward_deps += lockdep_count_forward_deps(class); +#endif } #ifdef CONFIG_DEBUG_LOCKDEP DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused); @@ -294,6 +358,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v) #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " dependency chains: %11lu [max: %lu]\n", nr_lock_chains, MAX_LOCKDEP_CHAINS); + seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n", + nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS); #endif #ifdef CONFIG_TRACE_IRQFLAGS @@ -406,8 +472,9 @@ static void snprint_time(char *buf, size_t bufsiz, s64 nr) { unsigned long rem; + nr += 5; /* for display rounding */ rem = do_div(nr, 1000); /* XXX: do_div_signed */ - snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10); + snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, (int)rem/10); } static void seq_time(struct seq_file *m, s64 time) @@ -661,6 +728,10 @@ static const struct file_operations proc_lock_stat_operations = { static int __init lockdep_proc_init(void) { proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations); +#ifdef CONFIG_PROVE_LOCKING + proc_create("lockdep_chains", S_IRUSR, NULL, + &proc_lockdep_chains_operations); +#endif proc_create("lockdep_stats", S_IRUSR, NULL, &proc_lockdep_stats_operations); diff --git a/kernel/marker.c b/kernel/marker.c index b5a9fe1..7d1faec 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -55,8 +55,8 @@ static DEFINE_MUTEX(markers_mutex); struct marker_entry { struct hlist_node hlist; char *format; - void (*call)(const struct marker *mdata, /* Probe wrapper */ - void *call_private, const char *fmt, ...); + /* Probe wrapper */ + void (*call)(const struct marker *mdata, void *call_private, ...); struct marker_probe_closure single; struct marker_probe_closure *multi; int refcount; /* Number of times armed. 0 if disarmed. */ @@ -91,15 +91,13 @@ EXPORT_SYMBOL_GPL(__mark_empty_function); * marker_probe_cb Callback that prepares the variable argument list for probes. * @mdata: pointer of type struct marker * @call_private: caller site private data - * @fmt: format string * @...: Variable argument list. * * Since we do not use "typical" pointer based RCU in the 1 argument case, we * need to put a full smp_rmb() in this branch. This is why we do not use * rcu_dereference() for the pointer read. */ -void marker_probe_cb(const struct marker *mdata, void *call_private, - const char *fmt, ...) +void marker_probe_cb(const struct marker *mdata, void *call_private, ...) { va_list args; char ptype; @@ -120,13 +118,19 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, /* Must read the ptr before private data. They are not data * dependant, so we put an explicit smp_rmb() here. */ smp_rmb(); - va_start(args, fmt); - func(mdata->single.probe_private, call_private, fmt, &args); + va_start(args, call_private); + func(mdata->single.probe_private, call_private, mdata->format, + &args); va_end(args); } else { struct marker_probe_closure *multi; int i; /* + * Read mdata->ptype before mdata->multi. + */ + smp_rmb(); + multi = mdata->multi; + /* * multi points to an array, therefore accessing the array * depends on reading multi. However, even in this case, * we must insure that the pointer is read _before_ the array @@ -134,11 +138,10 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, * in the fast path, so put the explicit barrier here. */ smp_read_barrier_depends(); - multi = mdata->multi; for (i = 0; multi[i].func; i++) { - va_start(args, fmt); - multi[i].func(multi[i].probe_private, call_private, fmt, - &args); + va_start(args, call_private); + multi[i].func(multi[i].probe_private, call_private, + mdata->format, &args); va_end(args); } } @@ -150,13 +153,11 @@ EXPORT_SYMBOL_GPL(marker_probe_cb); * marker_probe_cb Callback that does not prepare the variable argument list. * @mdata: pointer of type struct marker * @call_private: caller site private data - * @fmt: format string * @...: Variable argument list. * * Should be connected to markers "MARK_NOARGS". */ -void marker_probe_cb_noarg(const struct marker *mdata, - void *call_private, const char *fmt, ...) +void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...) { va_list args; /* not initialized */ char ptype; @@ -172,11 +173,17 @@ void marker_probe_cb_noarg(const struct marker *mdata, /* Must read the ptr before private data. They are not data * dependant, so we put an explicit smp_rmb() here. */ smp_rmb(); - func(mdata->single.probe_private, call_private, fmt, &args); + func(mdata->single.probe_private, call_private, mdata->format, + &args); } else { struct marker_probe_closure *multi; int i; /* + * Read mdata->ptype before mdata->multi. + */ + smp_rmb(); + multi = mdata->multi; + /* * multi points to an array, therefore accessing the array * depends on reading multi. However, even in this case, * we must insure that the pointer is read _before_ the array @@ -184,10 +191,9 @@ void marker_probe_cb_noarg(const struct marker *mdata, * in the fast path, so put the explicit barrier here. */ smp_read_barrier_depends(); - multi = mdata->multi; for (i = 0; multi[i].func; i++) - multi[i].func(multi[i].probe_private, call_private, fmt, - &args); + multi[i].func(multi[i].probe_private, call_private, + mdata->format, &args); } preempt_enable(); } @@ -443,7 +449,7 @@ static int remove_marker(const char *name) hlist_del(&e->hlist); /* Make sure the call_rcu has been executed */ if (e->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); kfree(e); return 0; } @@ -478,7 +484,7 @@ static int marker_set_format(struct marker_entry **entry, const char *format) hlist_del(&(*entry)->hlist); /* Make sure the call_rcu has been executed */ if ((*entry)->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); kfree(*entry); *entry = e; trace_mark(core_marker_format, "name %s format %s", @@ -657,7 +663,7 @@ int marker_probe_register(const char *name, const char *format, * make sure it's executed now. */ if (entry->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); old = marker_entry_add_probe(entry, probe, probe_private); if (IS_ERR(old)) { ret = PTR_ERR(old); @@ -672,10 +678,7 @@ int marker_probe_register(const char *name, const char *format, entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); -#ifdef CONFIG_PREEMPT_RCU - synchronize_sched(); /* Until we have the call_rcu_sched() */ -#endif - call_rcu(&entry->rcu, free_old_closure); + call_rcu_sched(&entry->rcu, free_old_closure); end: mutex_unlock(&markers_mutex); return ret; @@ -706,7 +709,7 @@ int marker_probe_unregister(const char *name, if (!entry) goto end; if (entry->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); old = marker_entry_remove_probe(entry, probe, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ @@ -718,10 +721,7 @@ int marker_probe_unregister(const char *name, entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); -#ifdef CONFIG_PREEMPT_RCU - synchronize_sched(); /* Until we have the call_rcu_sched() */ -#endif - call_rcu(&entry->rcu, free_old_closure); + call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(name); /* Ignore busy error message */ ret = 0; end: @@ -788,7 +788,7 @@ int marker_probe_unregister_private_data(marker_probe_func *probe, goto end; } if (entry->rcu_pending) - rcu_barrier(); + rcu_barrier_sched(); old = marker_entry_remove_probe(entry, NULL, probe_private); mutex_unlock(&markers_mutex); marker_update_probes(); /* may update entry */ @@ -799,10 +799,7 @@ int marker_probe_unregister_private_data(marker_probe_func *probe, entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); -#ifdef CONFIG_PREEMPT_RCU - synchronize_sched(); /* Until we have the call_rcu_sched() */ -#endif - call_rcu(&entry->rcu, free_old_closure); + call_rcu_sched(&entry->rcu, free_old_closure); remove_marker(entry->name); /* Ignore busy error message */ end: mutex_unlock(&markers_mutex); diff --git a/kernel/module.c b/kernel/module.c index 5f80478..9db1191 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -70,6 +70,9 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq); static BLOCKING_NOTIFIER_HEAD(module_notify_list); +/* Bounds of module allocation, for speeding __module_text_address */ +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + int register_module_notifier(struct notifier_block * nb) { return blocking_notifier_chain_register(&module_notify_list, nb); @@ -134,17 +137,19 @@ extern const struct kernel_symbol __start___ksymtab_gpl[]; extern const struct kernel_symbol __stop___ksymtab_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; -extern const struct kernel_symbol __start___ksymtab_unused[]; -extern const struct kernel_symbol __stop___ksymtab_unused[]; -extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; -extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; extern const unsigned long __start___kcrctab[]; extern const unsigned long __start___kcrctab_gpl[]; extern const unsigned long __start___kcrctab_gpl_future[]; +#ifdef CONFIG_UNUSED_SYMBOLS +extern const struct kernel_symbol __start___ksymtab_unused[]; +extern const struct kernel_symbol __stop___ksymtab_unused[]; +extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; +extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const unsigned long __start___kcrctab_unused[]; extern const unsigned long __start___kcrctab_unused_gpl[]; +#endif #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL @@ -152,152 +157,170 @@ extern const unsigned long __start___kcrctab_unused_gpl[]; #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) #endif -/* lookup symbol in given range of kernel_symbols */ -static const struct kernel_symbol *lookup_symbol(const char *name, - const struct kernel_symbol *start, - const struct kernel_symbol *stop) -{ - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; -} - -static bool always_ok(bool gplok, bool warn, const char *name) -{ - return true; -} - -static bool printk_unused_warning(bool gplok, bool warn, const char *name) -{ - if (warn) { - printk(KERN_WARNING "Symbol %s is marked as UNUSED, " - "however this module is using it.\n", name); - printk(KERN_WARNING - "This symbol will go away in the future.\n"); - printk(KERN_WARNING - "Please evalute if this is the right api to use and if " - "it really is, submit a report the linux kernel " - "mailinglist together with submitting your code for " - "inclusion.\n"); - } - return true; -} - -static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name) -{ - if (!gplok) - return false; - return printk_unused_warning(gplok, warn, name); -} - -static bool gpl_only(bool gplok, bool warn, const char *name) -{ - return gplok; -} - -static bool warn_if_not_gpl(bool gplok, bool warn, const char *name) -{ - if (!gplok && warn) { - printk(KERN_WARNING "Symbol %s is being used " - "by a non-GPL module, which will not " - "be allowed in the future\n", name); - printk(KERN_WARNING "Please see the file " - "Documentation/feature-removal-schedule.txt " - "in the kernel source tree for more details.\n"); - } - return true; -} - struct symsearch { const struct kernel_symbol *start, *stop; const unsigned long *crcs; - bool (*check)(bool gplok, bool warn, const char *name); + enum { + NOT_GPL_ONLY, + GPL_ONLY, + WILL_BE_GPL_ONLY, + } licence; + bool unused; }; -/* Look through this array of symbol tables for a symbol match which - * passes the check function. */ -static const struct kernel_symbol *search_symarrays(const struct symsearch *arr, - unsigned int num, - const char *name, - bool gplok, - bool warn, - const unsigned long **crc) +static bool each_symbol_in_section(const struct symsearch *arr, + unsigned int arrsize, + struct module *owner, + bool (*fn)(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data), + void *data) { - unsigned int i; - const struct kernel_symbol *ks; - - for (i = 0; i < num; i++) { - ks = lookup_symbol(name, arr[i].start, arr[i].stop); - if (!ks || !arr[i].check(gplok, warn, name)) - continue; + unsigned int i, j; - if (crc) - *crc = symversion(arr[i].crcs, ks - arr[i].start); - return ks; + for (j = 0; j < arrsize; j++) { + for (i = 0; i < arr[j].stop - arr[j].start; i++) + if (fn(&arr[j], owner, i, data)) + return true; } - return NULL; + + return false; } -/* Find a symbol, return value, (optional) crc and (optional) module - * which owns it */ -static unsigned long find_symbol(const char *name, - struct module **owner, - const unsigned long **crc, - bool gplok, - bool warn) +/* Returns true as soon as fn returns true, otherwise false. */ +static bool each_symbol(bool (*fn)(const struct symsearch *arr, + struct module *owner, + unsigned int symnum, void *data), + void *data) { struct module *mod; - const struct kernel_symbol *ks; const struct symsearch arr[] = { { __start___ksymtab, __stop___ksymtab, __start___kcrctab, - always_ok }, + NOT_GPL_ONLY, false }, { __start___ksymtab_gpl, __stop___ksymtab_gpl, - __start___kcrctab_gpl, gpl_only }, + __start___kcrctab_gpl, + GPL_ONLY, false }, { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, - __start___kcrctab_gpl_future, warn_if_not_gpl }, + __start___kcrctab_gpl_future, + WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { __start___ksymtab_unused, __stop___ksymtab_unused, - __start___kcrctab_unused, printk_unused_warning }, + __start___kcrctab_unused, + NOT_GPL_ONLY, true }, { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, - __start___kcrctab_unused_gpl, gpl_only_unused_warning }, + __start___kcrctab_unused_gpl, + GPL_ONLY, true }, +#endif }; - /* Core kernel first. */ - ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc); - if (ks) { - if (owner) - *owner = NULL; - return ks->value; - } + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) + return true; - /* Now try modules. */ list_for_each_entry(mod, &modules, list) { struct symsearch arr[] = { { mod->syms, mod->syms + mod->num_syms, mod->crcs, - always_ok }, + NOT_GPL_ONLY, false }, { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, - mod->gpl_crcs, gpl_only }, + mod->gpl_crcs, + GPL_ONLY, false }, { mod->gpl_future_syms, mod->gpl_future_syms + mod->num_gpl_future_syms, - mod->gpl_future_crcs, warn_if_not_gpl }, + mod->gpl_future_crcs, + WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->unused_syms + mod->num_unused_syms, - mod->unused_crcs, printk_unused_warning }, + mod->unused_crcs, + NOT_GPL_ONLY, true }, { mod->unused_gpl_syms, mod->unused_gpl_syms + mod->num_unused_gpl_syms, - mod->unused_gpl_crcs, gpl_only_unused_warning }, + mod->unused_gpl_crcs, + GPL_ONLY, true }, +#endif }; - ks = search_symarrays(arr, ARRAY_SIZE(arr), - name, gplok, warn, crc); - if (ks) { - if (owner) - *owner = mod; - return ks->value; + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) + return true; + } + return false; +} + +struct find_symbol_arg { + /* Input */ + const char *name; + bool gplok; + bool warn; + + /* Output */ + struct module *owner; + const unsigned long *crc; + unsigned long value; +}; + +static bool find_symbol_in_section(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) +{ + struct find_symbol_arg *fsa = data; + + if (strcmp(syms->start[symnum].name, fsa->name) != 0) + return false; + + if (!fsa->gplok) { + if (syms->licence == GPL_ONLY) + return false; + if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { + printk(KERN_WARNING "Symbol %s is being used " + "by a non-GPL module, which will not " + "be allowed in the future\n", fsa->name); + printk(KERN_WARNING "Please see the file " + "Documentation/feature-removal-schedule.txt " + "in the kernel source tree for more details.\n"); } } +#ifdef CONFIG_UNUSED_SYMBOLS + if (syms->unused && fsa->warn) { + printk(KERN_WARNING "Symbol %s is marked as UNUSED, " + "however this module is using it.\n", fsa->name); + printk(KERN_WARNING + "This symbol will go away in the future.\n"); + printk(KERN_WARNING + "Please evalute if this is the right api to use and if " + "it really is, submit a report the linux kernel " + "mailinglist together with submitting your code for " + "inclusion.\n"); + } +#endif + + fsa->owner = owner; + fsa->crc = symversion(syms->crcs, symnum); + fsa->value = syms->start[symnum].value; + return true; +} + +/* Find a symbol, return value, (optional) crc and (optional) module + * which owns it */ +static unsigned long find_symbol(const char *name, + struct module **owner, + const unsigned long **crc, + bool gplok, + bool warn) +{ + struct find_symbol_arg fsa; + + fsa.name = name; + fsa.gplok = gplok; + fsa.warn = warn; + + if (each_symbol(find_symbol_in_section, &fsa)) { + if (owner) + *owner = fsa.owner; + if (crc) + *crc = fsa.crc; + return fsa.value; + } + DEBUGP("Failed to find symbol %s\n", name); return -ENOENT; } @@ -639,8 +662,8 @@ static int __try_stop_module(void *_sref) { struct stopref *sref = _sref; - /* If it's not unused, quit unless we are told to block. */ - if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) { + /* If it's not unused, quit unless we're forcing. */ + if (module_refcount(sref->mod) != 0) { if (!(*sref->forced = try_force_unload(sref->flags))) return -EWOULDBLOCK; } @@ -652,9 +675,16 @@ static int __try_stop_module(void *_sref) static int try_stop_module(struct module *mod, int flags, int *forced) { - struct stopref sref = { mod, flags, forced }; + if (flags & O_NONBLOCK) { + struct stopref sref = { mod, flags, forced }; - return stop_machine_run(__try_stop_module, &sref, NR_CPUS); + return stop_machine(__try_stop_module, &sref, NULL); + } else { + /* We don't need to stop the machine for this. */ + mod->state = MODULE_STATE_GOING; + synchronize_sched(); + return 0; + } } unsigned int module_refcount(struct module *mod) @@ -1386,7 +1416,7 @@ static int __unlink_module(void *_mod) static void free_module(struct module *mod) { /* Delete from various lists */ - stop_machine_run(__unlink_module, mod, NR_CPUS); + stop_machine(__unlink_module, mod, NULL); remove_notes_attrs(mod); remove_sect_attrs(mod); mod_kobject_remove(mod); @@ -1445,8 +1475,10 @@ static int verify_export_symbols(struct module *mod) { mod->syms, mod->num_syms }, { mod->gpl_syms, mod->num_gpl_syms }, { mod->gpl_future_syms, mod->num_gpl_future_syms }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->num_unused_syms }, { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, +#endif }; for (i = 0; i < ARRAY_SIZE(arr); i++) { @@ -1526,7 +1558,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs, } /* Update size with this section: return offset. */ -static long get_offset(unsigned long *size, Elf_Shdr *sechdr) +static long get_offset(unsigned int *size, Elf_Shdr *sechdr) { long ret; @@ -1659,6 +1691,19 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs, } #ifdef CONFIG_KALLSYMS + +/* lookup symbol in given range of kernel_symbols */ +static const struct kernel_symbol *lookup_symbol(const char *name, + const struct kernel_symbol *start, + const struct kernel_symbol *stop) +{ + const struct kernel_symbol *ks = start; + for (; ks < stop; ks++) + if (strcmp(ks->name, name) == 0) + return ks; + return NULL; +} + static int is_exported(const char *name, const struct module *mod) { if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab)) @@ -1738,9 +1783,23 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ +static void *module_alloc_update_bounds(unsigned long size) +{ + void *ret = module_alloc(size); + + if (ret) { + /* Update module bounds. */ + if ((unsigned long)ret < module_addr_min) + module_addr_min = (unsigned long)ret; + if ((unsigned long)ret + size > module_addr_max) + module_addr_max = (unsigned long)ret + size; + } + return ret; +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ -static struct module *load_module(void __user *umod, +static noinline struct module *load_module(void __user *umod, unsigned long len, const char __user *uargs) { @@ -1764,10 +1823,12 @@ static struct module *load_module(void __user *umod, unsigned int gplfutureindex; unsigned int gplfuturecrcindex; unsigned int unwindex = 0; +#ifdef CONFIG_UNUSED_SYMBOLS unsigned int unusedindex; unsigned int unusedcrcindex; unsigned int unusedgplindex; unsigned int unusedgplcrcindex; +#endif unsigned int markersindex; unsigned int markersstringsindex; struct module *mod; @@ -1850,13 +1911,15 @@ static struct module *load_module(void __user *umod, exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future"); - unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); - unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab"); gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl"); gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future"); +#ifdef CONFIG_UNUSED_SYMBOLS + unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); + unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused"); unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); +#endif setupindex = find_sec(hdr, sechdrs, secstrings, "__param"); exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table"); obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm"); @@ -1935,7 +1998,7 @@ static struct module *load_module(void __user *umod, layout_sections(mod, hdr, sechdrs, secstrings); /* Do the allocs. */ - ptr = module_alloc(mod->core_size); + ptr = module_alloc_update_bounds(mod->core_size); if (!ptr) { err = -ENOMEM; goto free_percpu; @@ -1943,7 +2006,7 @@ static struct module *load_module(void __user *umod, memset(ptr, 0, mod->core_size); mod->module_core = ptr; - ptr = module_alloc(mod->init_size); + ptr = module_alloc_update_bounds(mod->init_size); if (!ptr && mod->init_size) { err = -ENOMEM; goto free_core; @@ -2018,14 +2081,15 @@ static struct module *load_module(void __user *umod, mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size / sizeof(*mod->gpl_future_syms); - mod->num_unused_syms = sechdrs[unusedindex].sh_size / - sizeof(*mod->unused_syms); - mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / - sizeof(*mod->unused_gpl_syms); mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr; if (gplfuturecrcindex) mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr; +#ifdef CONFIG_UNUSED_SYMBOLS + mod->num_unused_syms = sechdrs[unusedindex].sh_size / + sizeof(*mod->unused_syms); + mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / + sizeof(*mod->unused_gpl_syms); mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr; if (unusedcrcindex) mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr; @@ -2033,13 +2097,17 @@ static struct module *load_module(void __user *umod, if (unusedgplcrcindex) mod->unused_gpl_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr; +#endif #ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !crcindex) || - (mod->num_gpl_syms && !gplcrcindex) || - (mod->num_gpl_future_syms && !gplfuturecrcindex) || - (mod->num_unused_syms && !unusedcrcindex) || - (mod->num_unused_gpl_syms && !unusedgplcrcindex)) { + if ((mod->num_syms && !crcindex) + || (mod->num_gpl_syms && !gplcrcindex) + || (mod->num_gpl_future_syms && !gplfuturecrcindex) +#ifdef CONFIG_UNUSED_SYMBOLS + || (mod->num_unused_syms && !unusedcrcindex) + || (mod->num_unused_gpl_syms && !unusedgplcrcindex) +#endif + ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); err = try_to_force_load(mod, "nocrc"); if (err) @@ -2129,7 +2197,7 @@ static struct module *load_module(void __user *umod, /* Now sew it into the lists so we can get lockdep and oops * info during argument parsing. Noone should access us, since * strong_try_module_get() will fail. */ - stop_machine_run(__link_module, mod, NR_CPUS); + stop_machine(__link_module, mod, NULL); /* Size of section 0 is 0, so this works well if no params */ err = parse_args(mod->name, mod->args, @@ -2163,7 +2231,7 @@ static struct module *load_module(void __user *umod, return mod; unlink: - stop_machine_run(__unlink_module, mod, NR_CPUS); + stop_machine(__unlink_module, mod, NULL); module_arch_cleanup(mod); cleanup: kobject_del(&mod->mkobj.kobj); @@ -2220,7 +2288,7 @@ sys_init_module(void __user *umod, /* Start the module */ if (mod->init != NULL) - ret = mod->init(); + ret = do_one_initcall(mod->init); if (ret < 0) { /* Init routine failed: abort. Try to protect us from buggy refcounters. */ @@ -2512,7 +2580,7 @@ static int m_show(struct seq_file *m, void *p) struct module *mod = list_entry(p, struct module, list); char buf[8]; - seq_printf(m, "%s %lu", + seq_printf(m, "%s %u", mod->name, mod->init_size + mod->core_size); print_unload_info(m, mod); @@ -2595,6 +2663,9 @@ struct module *__module_text_address(unsigned long addr) { struct module *mod; + if (addr < module_addr_min || addr > module_addr_max) + return NULL; + list_for_each_entry(mod, &modules, list) if (within(addr, mod->module_init, mod->init_text_size) || within(addr, mod->module_core, mod->core_text_size)) diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c index 3aaa06c..1d94160 100644 --- a/kernel/mutex-debug.c +++ b/kernel/mutex-debug.c @@ -79,8 +79,8 @@ void debug_mutex_unlock(struct mutex *lock) if (unlikely(!debug_locks)) return; - DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); DEBUG_LOCKS_WARN_ON(lock->magic != lock); + DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); } diff --git a/kernel/mutex.c b/kernel/mutex.c index d046a34..12c779d 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -34,6 +34,7 @@ /*** * mutex_init - initialize the mutex * @lock: the mutex to be initialized + * @key: the lock_class_key for the class; used by mutex lock debugging * * Initialize the mutex to unlocked state. * @@ -165,10 +166,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, * got a signal? (This code gets eliminated in the * TASK_UNINTERRUPTIBLE case.) */ - if (unlikely((state == TASK_INTERRUPTIBLE && - signal_pending(task)) || - (state == TASK_KILLABLE && - fatal_signal_pending(task)))) { + if (unlikely(signal_pending_state(state, task))) { mutex_remove_waiter(lock, &waiter, task_thread_info(task)); mutex_release(&lock->dep_map, 1, ip); diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c index 48d7ed6..43c2111 100644 --- a/kernel/ns_cgroup.c +++ b/kernel/ns_cgroup.c @@ -7,6 +7,7 @@ #include <linux/module.h> #include <linux/cgroup.h> #include <linux/fs.h> +#include <linux/proc_fs.h> #include <linux/slab.h> #include <linux/nsproxy.h> @@ -24,9 +25,12 @@ static inline struct ns_cgroup *cgroup_to_ns( struct ns_cgroup, css); } -int ns_cgroup_clone(struct task_struct *task) +int ns_cgroup_clone(struct task_struct *task, struct pid *pid) { - return cgroup_clone(task, &ns_subsys); + char name[PROC_NUMBUF]; + + snprintf(name, PROC_NUMBUF, "%d", pid_vnr(pid)); + return cgroup_clone(task, &ns_subsys, name); } /* diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index adc7851..1d3ef29 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -14,7 +14,6 @@ */ #include <linux/module.h> -#include <linux/version.h> #include <linux/nsproxy.h> #include <linux/init_task.h> #include <linux/mnt_namespace.h> @@ -157,12 +156,6 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) goto out; } - err = ns_cgroup_clone(tsk); - if (err) { - put_nsproxy(new_ns); - goto out; - } - tsk->nsproxy = new_ns; out: @@ -209,7 +202,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, goto out; } - err = ns_cgroup_clone(current); + err = ns_cgroup_clone(current, task_pid(current)); if (err) put_nsproxy(*new_nsp); diff --git a/kernel/panic.c b/kernel/panic.c index c35c9ec..e0a87bb 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -321,6 +321,28 @@ void warn_on_slowpath(const char *file, int line) add_taint(TAINT_WARN); } EXPORT_SYMBOL(warn_on_slowpath); + + +void warn_slowpath(const char *file, int line, const char *fmt, ...) +{ + va_list args; + char function[KSYM_SYMBOL_LEN]; + unsigned long caller = (unsigned long)__builtin_return_address(0); + sprint_symbol(function, caller); + + printk(KERN_WARNING "------------[ cut here ]------------\n"); + printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file, + line, function); + va_start(args, fmt); + vprintk(fmt, args); + va_end(args); + + print_modules(); + dump_stack(); + print_oops_end_marker(); + add_taint(TAINT_WARN); +} +EXPORT_SYMBOL(warn_slowpath); #endif #ifdef CONFIG_CC_STACKPROTECTOR diff --git a/kernel/pid.c b/kernel/pid.c index 20d59fa..064e76a 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -30,6 +30,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/init.h> +#include <linux/rculist.h> #include <linux/bootmem.h> #include <linux/hash.h> #include <linux/pid_namespace.h> @@ -308,12 +309,6 @@ struct pid *find_vpid(int nr) } EXPORT_SYMBOL_GPL(find_vpid); -struct pid *find_pid(int nr) -{ - return find_pid_ns(nr, &init_pid_ns); -} -EXPORT_SYMBOL_GPL(find_pid); - /* * attach_pid() must be called with the tasklist_lock write-held. */ @@ -434,6 +429,7 @@ struct pid *find_get_pid(pid_t nr) return pid; } +EXPORT_SYMBOL_GPL(find_get_pid); pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns) { @@ -481,7 +477,7 @@ EXPORT_SYMBOL(task_session_nr_ns); /* * Used by proc to find the first pid that is greater then or equal to nr. * - * If there is a pid at nr this function is exactly the same as find_pid. + * If there is a pid at nr this function is exactly the same as find_pid_ns. */ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) { @@ -496,7 +492,6 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) return pid; } -EXPORT_SYMBOL_GPL(find_get_pid); /* * The pid hash table is scaled according to the amount of memory in the diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 98702b4..fab8ea8 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -12,6 +12,7 @@ #include <linux/pid_namespace.h> #include <linux/syscalls.h> #include <linux/err.h> +#include <linux/acct.h> #define BITS_PER_PAGE (PAGE_SIZE*8) @@ -71,7 +72,7 @@ static struct pid_namespace *create_pid_namespace(unsigned int level) struct pid_namespace *ns; int i; - ns = kmem_cache_alloc(pid_ns_cachep, GFP_KERNEL); + ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL); if (ns == NULL) goto out; @@ -84,17 +85,13 @@ static struct pid_namespace *create_pid_namespace(unsigned int level) goto out_free_map; kref_init(&ns->kref); - ns->last_pid = 0; - ns->child_reaper = NULL; ns->level = level; set_bit(0, ns->pidmap[0].page); atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1); - for (i = 1; i < PIDMAP_ENTRIES; i++) { - ns->pidmap[i].page = NULL; + for (i = 1; i < PIDMAP_ENTRIES; i++) atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE); - } return ns; @@ -182,9 +179,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) rc = sys_wait4(-1, NULL, __WALL, NULL); } while (rc != -ECHILD); - - /* Child reaper for the pid namespace is going away */ - pid_ns->child_reaper = NULL; + acct_exit_ns(pid_ns); return; } diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index 0afe32b..dfdec52 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -24,11 +24,12 @@ * requirement that the application has is cleaned up when closes the file * pointer or exits the pm_qos_object will get an opportunity to clean up. * - * mark gross mgross@linux.intel.com + * Mark Gross <mgross@linux.intel.com> */ #include <linux/pm_qos_params.h> #include <linux/sched.h> +#include <linux/smp_lock.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/time.h> @@ -42,7 +43,7 @@ #include <linux/uaccess.h> /* - * locking rule: all changes to target_value or requirements or notifiers lists + * locking rule: all changes to requirements or notifiers lists * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock * held, taken with _irqsave. One lock to rule them all */ @@ -65,7 +66,7 @@ struct pm_qos_object { struct miscdevice pm_qos_power_miscdev; char *name; s32 default_value; - s32 target_value; + atomic_t target_value; s32 (*comparitor)(s32, s32); }; @@ -76,7 +77,7 @@ static struct pm_qos_object cpu_dma_pm_qos = { .notifiers = &cpu_dma_lat_notifier, .name = "cpu_dma_latency", .default_value = 2000 * USEC_PER_SEC, - .target_value = 2000 * USEC_PER_SEC, + .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC), .comparitor = min_compare }; @@ -86,7 +87,7 @@ static struct pm_qos_object network_lat_pm_qos = { .notifiers = &network_lat_notifier, .name = "network_latency", .default_value = 2000 * USEC_PER_SEC, - .target_value = 2000 * USEC_PER_SEC, + .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC), .comparitor = min_compare }; @@ -98,7 +99,7 @@ static struct pm_qos_object network_throughput_pm_qos = { .notifiers = &network_throughput_notifier, .name = "network_throughput", .default_value = 0, - .target_value = 0, + .target_value = ATOMIC_INIT(0), .comparitor = max_compare }; @@ -149,11 +150,11 @@ static void update_target(int target) extreme_value = pm_qos_array[target]->comparitor( extreme_value, node->value); } - if (pm_qos_array[target]->target_value != extreme_value) { + if (atomic_read(&pm_qos_array[target]->target_value) != extreme_value) { call_notifier = 1; - pm_qos_array[target]->target_value = extreme_value; + atomic_set(&pm_qos_array[target]->target_value, extreme_value); pr_debug(KERN_ERR "new target for qos %d is %d\n", target, - pm_qos_array[target]->target_value); + atomic_read(&pm_qos_array[target]->target_value)); } spin_unlock_irqrestore(&pm_qos_lock, flags); @@ -192,14 +193,7 @@ static int find_pm_qos_object_by_minor(int minor) */ int pm_qos_requirement(int pm_qos_class) { - int ret_val; - unsigned long flags; - - spin_lock_irqsave(&pm_qos_lock, flags); - ret_val = pm_qos_array[pm_qos_class]->target_value; - spin_unlock_irqrestore(&pm_qos_lock, flags); - - return ret_val; + return atomic_read(&pm_qos_array[pm_qos_class]->target_value); } EXPORT_SYMBOL_GPL(pm_qos_requirement); @@ -210,8 +204,8 @@ EXPORT_SYMBOL_GPL(pm_qos_requirement); * @value: defines the qos request * * This function inserts a new entry in the pm_qos_class list of requested qos - * performance charactoistics. It recomputes the agregate QoS expectations for - * the pm_qos_class of parrameters. + * performance characteristics. It recomputes the aggregate QoS expectations + * for the pm_qos_class of parameters. */ int pm_qos_add_requirement(int pm_qos_class, char *name, s32 value) { @@ -249,10 +243,10 @@ EXPORT_SYMBOL_GPL(pm_qos_add_requirement); * @name: identifies the request * @value: defines the qos request * - * Updates an existing qos requierement for the pm_qos_class of parameters along + * Updates an existing qos requirement for the pm_qos_class of parameters along * with updating the target pm_qos_class value. * - * If the named request isn't in the lest then no change is made. + * If the named request isn't in the list then no change is made. */ int pm_qos_update_requirement(int pm_qos_class, char *name, s32 new_value) { @@ -286,7 +280,7 @@ EXPORT_SYMBOL_GPL(pm_qos_update_requirement); * @pm_qos_class: identifies which list of qos request to us * @name: identifies the request * - * Will remove named qos request from pm_qos_class list of parrameters and + * Will remove named qos request from pm_qos_class list of parameters and * recompute the current target value for the pm_qos_class. */ void pm_qos_remove_requirement(int pm_qos_class, char *name) @@ -318,7 +312,7 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_requirement); * @notifier: notifier block managed by caller. * * will register the notifier into a notification chain that gets called - * uppon changes to the pm_qos_class target value. + * upon changes to the pm_qos_class target value. */ int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) { @@ -337,7 +331,7 @@ EXPORT_SYMBOL_GPL(pm_qos_add_notifier); * @notifier: notifier block to be removed. * * will remove the notifier from the notification chain that gets called - * uppon changes to the pm_qos_class target value. + * upon changes to the pm_qos_class target value. */ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) { @@ -358,15 +352,19 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) int ret; long pm_qos_class; + lock_kernel(); pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { filp->private_data = (void *)pm_qos_class; sprintf(name, "process_%d", current->pid); ret = pm_qos_add_requirement(pm_qos_class, name, PM_QOS_DEFAULT_VALUE); - if (ret >= 0) + if (ret >= 0) { + unlock_kernel(); return 0; + } } + unlock_kernel(); return -EPERM; } diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index f1525ad..c42a03a 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1037,6 +1037,9 @@ static void check_thread_timers(struct task_struct *tsk, sig->rlim[RLIMIT_RTTIME].rlim_cur += USEC_PER_SEC; } + printk(KERN_INFO + "RT Watchdog Timeout: %s[%d]\n", + tsk->comm, task_pid_nr(tsk)); __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); } } diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index dbd8398..5131e54 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -289,21 +289,29 @@ void do_schedule_next_timer(struct siginfo *info) else schedule_next_timer(timr); - info->si_overrun = timr->it_overrun_last; + info->si_overrun += timr->it_overrun_last; } if (timr) unlock_timer(timr, flags); } -int posix_timer_event(struct k_itimer *timr,int si_private) +int posix_timer_event(struct k_itimer *timr, int si_private) { - memset(&timr->sigq->info, 0, sizeof(siginfo_t)); + /* + * FIXME: if ->sigq is queued we can race with + * dequeue_signal()->do_schedule_next_timer(). + * + * If dequeue_signal() sees the "right" value of + * si_sys_private it calls do_schedule_next_timer(). + * We re-queue ->sigq and drop ->it_lock(). + * do_schedule_next_timer() locks the timer + * and re-schedules it while ->sigq is pending. + * Not really bad, but not that we want. + */ timr->sigq->info.si_sys_private = si_private; - /* Send signal to the process that owns this timer.*/ timr->sigq->info.si_signo = timr->it_sigev_signo; - timr->sigq->info.si_errno = 0; timr->sigq->info.si_code = SI_TIMER; timr->sigq->info.si_tid = timr->it_id; timr->sigq->info.si_value = timr->it_sigev_value; @@ -433,8 +441,9 @@ static struct k_itimer * alloc_posix_timer(void) return tmr; if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { kmem_cache_free(posix_timers_cache, tmr); - tmr = NULL; + return NULL; } + memset(&tmr->sigq->info, 0, sizeof(siginfo_t)); return tmr; } @@ -449,9 +458,6 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) spin_unlock_irqrestore(&idr_lock, flags); } sigqueue_free(tmr->sigq); - if (unlikely(tmr->it_process) && - tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(tmr->it_process); kmem_cache_free(posix_timers_cache, tmr); } @@ -856,11 +862,10 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_process) { - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); - timer->it_process = NULL; - } + if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) + put_task_struct(timer->it_process); + timer->it_process = NULL; + unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); return 0; @@ -885,11 +890,10 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_process) { - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); - timer->it_process = NULL; - } + if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) + put_task_struct(timer->it_process); + timer->it_process = NULL; + unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); } diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index b45da40..dcd165f 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -82,7 +82,7 @@ config PM_SLEEP_SMP config PM_SLEEP bool - depends on SUSPEND || HIBERNATION + depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y config SUSPEND @@ -94,6 +94,17 @@ config SUSPEND powered and thus its contents are preserved, such as the suspend-to-RAM state (e.g. the ACPI S3 state). +config PM_TEST_SUSPEND + bool "Test suspend/resume and wakealarm during bootup" + depends on SUSPEND && PM_DEBUG && RTC_LIB=y + ---help--- + This option will let you suspend your machine during bootup, and + make it wake up a few seconds later using an RTC wakeup alarm. + Enable this with a kernel parameter like "test_suspend=mem". + + You probably want to have your system's RTC driver statically + linked, ensuring that it's available when this test runs. + config SUSPEND_FREEZER bool "Enable freezer for suspend to RAM/standby" \ if ARCH_WANTS_FREEZER_CONTROL || BROKEN diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 14a656c..bbd85c6 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -21,6 +21,7 @@ #include <linux/console.h> #include <linux/cpu.h> #include <linux/freezer.h> +#include <linux/ftrace.h> #include "power.h" @@ -180,6 +181,17 @@ static void platform_restore_cleanup(int platform_mode) } /** + * platform_recover - recover the platform from a failure to suspend + * devices. + */ + +static void platform_recover(int platform_mode) +{ + if (platform_mode && hibernation_ops && hibernation_ops->recover) + hibernation_ops->recover(); +} + +/** * create_image - freeze devices that need to be frozen with interrupts * off, create the hibernation image and thaw those devices. Control * reappears in this routine after a restore. @@ -193,6 +205,7 @@ static int create_image(int platform_mode) if (error) return error; + device_pm_lock(); local_irq_disable(); /* At this point, device_suspend() has been called, but *not* * device_power_down(). We *must* call device_power_down() now. @@ -224,9 +237,11 @@ static int create_image(int platform_mode) /* NOTE: device_power_up() is just a resume() for devices * that suspended with irqs off ... no overall powerup. */ - device_power_up(); + device_power_up(in_suspend ? + (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); Enable_irqs: local_irq_enable(); + device_pm_unlock(); return error; } @@ -241,7 +256,7 @@ static int create_image(int platform_mode) int hibernation_snapshot(int platform_mode) { - int error; + int error, ftrace_save; /* Free memory before shutting down devices. */ error = swsusp_shrink_memory(); @@ -253,12 +268,13 @@ int hibernation_snapshot(int platform_mode) goto Close; suspend_console(); + ftrace_save = __ftrace_enabled_save(); error = device_suspend(PMSG_FREEZE); if (error) - goto Resume_console; + goto Recover_platform; if (hibernation_test(TEST_DEVICES)) - goto Resume_devices; + goto Recover_platform; error = platform_pre_snapshot(platform_mode); if (error || hibernation_test(TEST_PLATFORM)) @@ -280,12 +296,17 @@ int hibernation_snapshot(int platform_mode) Finish: platform_finish(platform_mode); Resume_devices: - device_resume(); - Resume_console: + device_resume(in_suspend ? + (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + __ftrace_enabled_restore(ftrace_save); resume_console(); Close: platform_end(platform_mode); return error; + + Recover_platform: + platform_recover(platform_mode); + goto Resume_devices; } /** @@ -300,8 +321,9 @@ static int resume_target_kernel(void) { int error; + device_pm_lock(); local_irq_disable(); - error = device_power_down(PMSG_PRETHAW); + error = device_power_down(PMSG_QUIESCE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting resume\n"); @@ -329,9 +351,10 @@ static int resume_target_kernel(void) swsusp_free(); restore_processor_state(); touch_softlockup_watchdog(); - device_power_up(); + device_power_up(PMSG_RECOVER); Enable_irqs: local_irq_enable(); + device_pm_unlock(); return error; } @@ -346,11 +369,12 @@ static int resume_target_kernel(void) int hibernation_restore(int platform_mode) { - int error; + int error, ftrace_save; pm_prepare_console(); suspend_console(); - error = device_suspend(PMSG_PRETHAW); + ftrace_save = __ftrace_enabled_save(); + error = device_suspend(PMSG_QUIESCE); if (error) goto Finish; @@ -362,8 +386,9 @@ int hibernation_restore(int platform_mode) enable_nonboot_cpus(); } platform_restore_cleanup(platform_mode); - device_resume(); + device_resume(PMSG_RECOVER); Finish: + __ftrace_enabled_restore(ftrace_save); resume_console(); pm_restore_console(); return error; @@ -376,7 +401,7 @@ int hibernation_restore(int platform_mode) int hibernation_platform_enter(void) { - int error; + int error, ftrace_save; if (!hibernation_ops) return -ENOSYS; @@ -391,9 +416,13 @@ int hibernation_platform_enter(void) goto Close; suspend_console(); + ftrace_save = __ftrace_enabled_save(); error = device_suspend(PMSG_HIBERNATE); - if (error) - goto Resume_console; + if (error) { + if (hibernation_ops->recover) + hibernation_ops->recover(); + goto Resume_devices; + } error = hibernation_ops->prepare(); if (error) @@ -403,6 +432,7 @@ int hibernation_platform_enter(void) if (error) goto Finish; + device_pm_lock(); local_irq_disable(); error = device_power_down(PMSG_HIBERNATE); if (!error) { @@ -411,6 +441,7 @@ int hibernation_platform_enter(void) while (1); } local_irq_enable(); + device_pm_unlock(); /* * We don't need to reenable the nonboot CPUs or resume consoles, since @@ -419,8 +450,8 @@ int hibernation_platform_enter(void) Finish: hibernation_ops->finish(); Resume_devices: - device_resume(); - Resume_console: + device_resume(PMSG_RESTORE); + __ftrace_enabled_restore(ftrace_save); resume_console(); Close: hibernation_ops->end(); diff --git a/kernel/power/main.c b/kernel/power/main.c index 6a6d5eb..540b16b 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -21,6 +21,7 @@ #include <linux/freezer.h> #include <linux/vmstat.h> #include <linux/syscalls.h> +#include <linux/ftrace.h> #include "power.h" @@ -132,6 +133,61 @@ static inline int suspend_test(int level) { return 0; } #ifdef CONFIG_SUSPEND +#ifdef CONFIG_PM_TEST_SUSPEND + +/* + * We test the system suspend code by setting an RTC wakealarm a short + * time in the future, then suspending. Suspending the devices won't + * normally take long ... some systems only need a few milliseconds. + * + * The time it takes is system-specific though, so when we test this + * during system bootup we allow a LOT of time. + */ +#define TEST_SUSPEND_SECONDS 5 + +static unsigned long suspend_test_start_time; + +static void suspend_test_start(void) +{ + /* FIXME Use better timebase than "jiffies", ideally a clocksource. + * What we want is a hardware counter that will work correctly even + * during the irqs-are-off stages of the suspend/resume cycle... + */ + suspend_test_start_time = jiffies; +} + +static void suspend_test_finish(const char *label) +{ + long nj = jiffies - suspend_test_start_time; + unsigned msec; + + msec = jiffies_to_msecs(abs(nj)); + pr_info("PM: %s took %d.%03d seconds\n", label, + msec / 1000, msec % 1000); + + /* Warning on suspend means the RTC alarm period needs to be + * larger -- the system was sooo slooowwww to suspend that the + * alarm (should have) fired before the system went to sleep! + * + * Warning on either suspend or resume also means the system + * has some performance issues. The stack dump of a WARN_ON + * is more likely to get the right attention than a printk... + */ + WARN_ON(msec > (TEST_SUSPEND_SECONDS * 1000)); +} + +#else + +static void suspend_test_start(void) +{ +} + +static void suspend_test_finish(const char *label) +{ +} + +#endif + /* This is just an arbitrary number */ #define FREE_PAGE_NUMBER (100) @@ -228,6 +284,7 @@ static int suspend_enter(suspend_state_t state) { int error = 0; + device_pm_lock(); arch_suspend_disable_irqs(); BUG_ON(!irqs_disabled()); @@ -239,10 +296,11 @@ static int suspend_enter(suspend_state_t state) if (!suspend_test(TEST_CORE)) error = suspend_ops->enter(state); - device_power_up(); + device_power_up(PMSG_RESUME); Done: arch_suspend_enable_irqs(); BUG_ON(irqs_disabled()); + device_pm_unlock(); return error; } @@ -253,7 +311,7 @@ static int suspend_enter(suspend_state_t state) */ int suspend_devices_and_enter(suspend_state_t state) { - int error; + int error, ftrace_save; if (!suspend_ops) return -ENOSYS; @@ -264,14 +322,16 @@ int suspend_devices_and_enter(suspend_state_t state) goto Close; } suspend_console(); + ftrace_save = __ftrace_enabled_save(); + suspend_test_start(); error = device_suspend(PMSG_SUSPEND); if (error) { printk(KERN_ERR "PM: Some devices failed to suspend\n"); - goto Resume_console; + goto Recover_platform; } - + suspend_test_finish("suspend devices"); if (suspend_test(TEST_DEVICES)) - goto Resume_devices; + goto Recover_platform; if (suspend_ops->prepare) { error = suspend_ops->prepare(); @@ -291,13 +351,20 @@ int suspend_devices_and_enter(suspend_state_t state) if (suspend_ops->finish) suspend_ops->finish(); Resume_devices: - device_resume(); - Resume_console: + suspend_test_start(); + device_resume(PMSG_RESUME); + suspend_test_finish("resume devices"); + __ftrace_enabled_restore(ftrace_save); resume_console(); Close: if (suspend_ops->end) suspend_ops->end(); return error; + + Recover_platform: + if (suspend_ops->recover) + suspend_ops->recover(); + goto Resume_devices; } /** @@ -515,3 +582,144 @@ static int __init pm_init(void) } core_initcall(pm_init); + + +#ifdef CONFIG_PM_TEST_SUSPEND + +#include <linux/rtc.h> + +/* + * To test system suspend, we need a hands-off mechanism to resume the + * system. RTCs wake alarms are a common self-contained mechanism. + */ + +static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) +{ + static char err_readtime[] __initdata = + KERN_ERR "PM: can't read %s time, err %d\n"; + static char err_wakealarm [] __initdata = + KERN_ERR "PM: can't set %s wakealarm, err %d\n"; + static char err_suspend[] __initdata = + KERN_ERR "PM: suspend test failed, error %d\n"; + static char info_test[] __initdata = + KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; + + unsigned long now; + struct rtc_wkalrm alm; + int status; + + /* this may fail if the RTC hasn't been initialized */ + status = rtc_read_time(rtc, &alm.time); + if (status < 0) { + printk(err_readtime, rtc->dev.bus_id, status); + return; + } + rtc_tm_to_time(&alm.time, &now); + + memset(&alm, 0, sizeof alm); + rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); + alm.enabled = true; + + status = rtc_set_alarm(rtc, &alm); + if (status < 0) { + printk(err_wakealarm, rtc->dev.bus_id, status); + return; + } + + if (state == PM_SUSPEND_MEM) { + printk(info_test, pm_states[state]); + status = pm_suspend(state); + if (status == -ENODEV) + state = PM_SUSPEND_STANDBY; + } + if (state == PM_SUSPEND_STANDBY) { + printk(info_test, pm_states[state]); + status = pm_suspend(state); + } + if (status < 0) + printk(err_suspend, status); + + /* Some platforms can't detect that the alarm triggered the + * wakeup, or (accordingly) disable it after it afterwards. + * It's supposed to give oneshot behavior; cope. + */ + alm.enabled = false; + rtc_set_alarm(rtc, &alm); +} + +static int __init has_wakealarm(struct device *dev, void *name_ptr) +{ + struct rtc_device *candidate = to_rtc_device(dev); + + if (!candidate->ops->set_alarm) + return 0; + if (!device_may_wakeup(candidate->dev.parent)) + return 0; + + *(char **)name_ptr = dev->bus_id; + return 1; +} + +/* + * Kernel options like "test_suspend=mem" force suspend/resume sanity tests + * at startup time. They're normally disabled, for faster boot and because + * we can't know which states really work on this particular system. + */ +static suspend_state_t test_state __initdata = PM_SUSPEND_ON; + +static char warn_bad_state[] __initdata = + KERN_WARNING "PM: can't test '%s' suspend state\n"; + +static int __init setup_test_suspend(char *value) +{ + unsigned i; + + /* "=mem" ==> "mem" */ + value++; + for (i = 0; i < PM_SUSPEND_MAX; i++) { + if (!pm_states[i]) + continue; + if (strcmp(pm_states[i], value) != 0) + continue; + test_state = (__force suspend_state_t) i; + return 0; + } + printk(warn_bad_state, value); + return 0; +} +__setup("test_suspend", setup_test_suspend); + +static int __init test_suspend(void) +{ + static char warn_no_rtc[] __initdata = + KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; + + char *pony = NULL; + struct rtc_device *rtc = NULL; + + /* PM is initialized by now; is that state testable? */ + if (test_state == PM_SUSPEND_ON) + goto done; + if (!valid_state(test_state)) { + printk(warn_bad_state, pm_states[test_state]); + goto done; + } + + /* RTCs have initialized by now too ... can we use one? */ + class_find_device(rtc_class, NULL, &pony, has_wakealarm); + if (pony) + rtc = rtc_class_open(pony); + if (!rtc) { + printk(warn_no_rtc); + goto done; + } + + /* go for it */ + test_wakealarm(rtc, test_state); + rtc_class_close(rtc); +done: + return 0; +} +late_initcall(test_suspend); + +#endif /* CONFIG_PM_TEST_SUSPEND */ diff --git a/kernel/power/power.h b/kernel/power/power.h index 700f44e..acc0c10 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -53,8 +53,6 @@ extern int hibernation_platform_enter(void); extern int pfn_is_nosave(unsigned long); -extern struct mutex pm_mutex; - #define power_attr(_name) \ static struct kobj_attribute _name##_attr = { \ .attr = { \ diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c index 678ec73..72016f0 100644 --- a/kernel/power/poweroff.c +++ b/kernel/power/poweroff.c @@ -10,6 +10,7 @@ #include <linux/pm.h> #include <linux/workqueue.h> #include <linux/reboot.h> +#include <linux/cpumask.h> /* * When the user hits Sys-Rq o to power down the machine this is the @@ -25,7 +26,8 @@ static DECLARE_WORK(poweroff_work, do_poweroff); static void handle_poweroff(int key, struct tty_struct *tty) { - schedule_work(&poweroff_work); + /* run sysrq poweroff on boot cpu */ + schedule_work_on(first_cpu(cpu_online_map), &poweroff_work); } static struct sysrq_key_op sysrq_poweroff_op = { diff --git a/kernel/power/process.c b/kernel/power/process.c index f1d0b34..278946a 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -19,9 +19,6 @@ */ #define TIMEOUT (20 * HZ) -#define FREEZER_KERNEL_THREADS 0 -#define FREEZER_USER_SPACE 1 - static inline int freezeable(struct task_struct * p) { if ((p == current) || @@ -84,63 +81,53 @@ static void fake_signal_wake_up(struct task_struct *p) spin_unlock_irqrestore(&p->sighand->siglock, flags); } -static int has_mm(struct task_struct *p) +static inline bool should_send_signal(struct task_struct *p) { - return (p->mm && !(p->flags & PF_BORROWED_MM)); + return !(p->flags & PF_FREEZER_NOSIG); } /** * freeze_task - send a freeze request to given task * @p: task to send the request to - * @with_mm_only: if set, the request will only be sent if the task has its - * own mm - * Return value: 0, if @with_mm_only is set and the task has no mm of its - * own or the task is frozen, 1, otherwise + * @sig_only: if set, the request will only be sent if the task has the + * PF_FREEZER_NOSIG flag unset + * Return value: 'false', if @sig_only is set and the task has + * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise * - * The freeze request is sent by seting the tasks's TIF_FREEZE flag and + * The freeze request is sent by setting the tasks's TIF_FREEZE flag and * either sending a fake signal to it or waking it up, depending on whether - * or not it has its own mm (ie. it is a user land task). If @with_mm_only - * is set and the task has no mm of its own (ie. it is a kernel thread), - * its TIF_FREEZE flag should not be set. - * - * The task_lock() is necessary to prevent races with exit_mm() or - * use_mm()/unuse_mm() from occuring. + * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task + * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its + * TIF_FREEZE flag will not be set. */ -static int freeze_task(struct task_struct *p, int with_mm_only) +static bool freeze_task(struct task_struct *p, bool sig_only) { - int ret = 1; + /* + * We first check if the task is freezing and next if it has already + * been frozen to avoid the race with frozen_process() which first marks + * the task as frozen and next clears its TIF_FREEZE. + */ + if (!freezing(p)) { + rmb(); + if (frozen(p)) + return false; - task_lock(p); - if (freezing(p)) { - if (has_mm(p)) { - if (!signal_pending(p)) - fake_signal_wake_up(p); - } else { - if (with_mm_only) - ret = 0; - else - wake_up_state(p, TASK_INTERRUPTIBLE); - } + if (!sig_only || should_send_signal(p)) + set_freeze_flag(p); + else + return false; + } + + if (should_send_signal(p)) { + if (!signal_pending(p)) + fake_signal_wake_up(p); + } else if (sig_only) { + return false; } else { - rmb(); - if (frozen(p)) { - ret = 0; - } else { - if (has_mm(p)) { - set_freeze_flag(p); - fake_signal_wake_up(p); - } else { - if (with_mm_only) { - ret = 0; - } else { - set_freeze_flag(p); - wake_up_state(p, TASK_INTERRUPTIBLE); - } - } - } + wake_up_state(p, TASK_INTERRUPTIBLE); } - task_unlock(p); - return ret; + + return true; } static void cancel_freezing(struct task_struct *p) @@ -156,13 +143,13 @@ static void cancel_freezing(struct task_struct *p) } } -static int try_to_freeze_tasks(int freeze_user_space) +static int try_to_freeze_tasks(bool sig_only) { struct task_struct *g, *p; unsigned long end_time; unsigned int todo; struct timeval start, end; - s64 elapsed_csecs64; + u64 elapsed_csecs64; unsigned int elapsed_csecs; do_gettimeofday(&start); @@ -175,7 +162,7 @@ static int try_to_freeze_tasks(int freeze_user_space) if (frozen(p) || !freezeable(p)) continue; - if (!freeze_task(p, freeze_user_space)) + if (!freeze_task(p, sig_only)) continue; /* @@ -235,13 +222,13 @@ int freeze_processes(void) int error; printk("Freezing user space processes ... "); - error = try_to_freeze_tasks(FREEZER_USER_SPACE); + error = try_to_freeze_tasks(true); if (error) goto Exit; printk("done.\n"); printk("Freezing remaining freezable tasks ... "); - error = try_to_freeze_tasks(FREEZER_KERNEL_THREADS); + error = try_to_freeze_tasks(false); if (error) goto Exit; printk("done."); @@ -251,7 +238,7 @@ int freeze_processes(void) return error; } -static void thaw_tasks(int thaw_user_space) +static void thaw_tasks(bool nosig_only) { struct task_struct *g, *p; @@ -260,7 +247,7 @@ static void thaw_tasks(int thaw_user_space) if (!freezeable(p)) continue; - if (!p->mm == thaw_user_space) + if (nosig_only && should_send_signal(p)) continue; thaw_process(p); @@ -271,8 +258,8 @@ static void thaw_tasks(int thaw_user_space) void thaw_processes(void) { printk("Restarting tasks ... "); - thaw_tasks(FREEZER_KERNEL_THREADS); - thaw_tasks(FREEZER_USER_SPACE); + thaw_tasks(true); + thaw_tasks(false); schedule(); printk("done.\n"); } diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 5f91a07..5d2ab83 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -205,8 +205,7 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave) * objects. The main list's elements are of type struct zone_bitmap * and each of them corresonds to one zone. For each zone bitmap * object there is a list of objects of type struct bm_block that - * represent each blocks of bit chunks in which information is - * stored. + * represent each blocks of bitmap in which information is stored. * * struct memory_bitmap contains a pointer to the main list of zone * bitmap objects, a struct bm_position used for browsing the bitmap, @@ -224,26 +223,27 @@ static void chain_free(struct chain_allocator *ca, int clear_page_nosave) * pfns that correspond to the start and end of the represented zone. * * struct bm_block contains a pointer to the memory page in which - * information is stored (in the form of a block of bit chunks - * of type unsigned long each). It also contains the pfns that - * correspond to the start and end of the represented memory area and - * the number of bit chunks in the block. + * information is stored (in the form of a block of bitmap) + * It also contains the pfns that correspond to the start and end of + * the represented memory area. */ #define BM_END_OF_MAP (~0UL) -#define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long)) -#define BM_BITS_PER_CHUNK (sizeof(long) << 3) #define BM_BITS_PER_BLOCK (PAGE_SIZE << 3) struct bm_block { struct bm_block *next; /* next element of the list */ unsigned long start_pfn; /* pfn represented by the first bit */ unsigned long end_pfn; /* pfn represented by the last bit plus 1 */ - unsigned int size; /* number of bit chunks */ - unsigned long *data; /* chunks of bits representing pages */ + unsigned long *data; /* bitmap representing pages */ }; +static inline unsigned long bm_block_bits(struct bm_block *bb) +{ + return bb->end_pfn - bb->start_pfn; +} + struct zone_bitmap { struct zone_bitmap *next; /* next element of the list */ unsigned long start_pfn; /* minimal pfn in this zone */ @@ -257,7 +257,6 @@ struct zone_bitmap { struct bm_position { struct zone_bitmap *zone_bm; struct bm_block *block; - int chunk; int bit; }; @@ -272,12 +271,6 @@ struct memory_bitmap { /* Functions that operate on memory bitmaps */ -static inline void memory_bm_reset_chunk(struct memory_bitmap *bm) -{ - bm->cur.chunk = 0; - bm->cur.bit = -1; -} - static void memory_bm_position_reset(struct memory_bitmap *bm) { struct zone_bitmap *zone_bm; @@ -285,7 +278,7 @@ static void memory_bm_position_reset(struct memory_bitmap *bm) zone_bm = bm->zone_bm_list; bm->cur.zone_bm = zone_bm; bm->cur.block = zone_bm->bm_blocks; - memory_bm_reset_chunk(bm); + bm->cur.bit = 0; } static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); @@ -394,12 +387,10 @@ memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) bb->start_pfn = pfn; if (nr >= BM_BITS_PER_BLOCK) { pfn += BM_BITS_PER_BLOCK; - bb->size = BM_CHUNKS_PER_BLOCK; nr -= BM_BITS_PER_BLOCK; } else { /* This is executed only once in the loop */ pfn += nr; - bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK); } bb->end_pfn = pfn; bb = bb->next; @@ -478,8 +469,8 @@ static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, } zone_bm->cur_block = bb; pfn -= bb->start_pfn; - *bit_nr = pfn % BM_BITS_PER_CHUNK; - *addr = bb->data + pfn / BM_BITS_PER_CHUNK; + *bit_nr = pfn; + *addr = bb->data; return 0; } @@ -528,36 +519,6 @@ static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) return test_bit(bit, addr); } -/* Two auxiliary functions for memory_bm_next_pfn */ - -/* Find the first set bit in the given chunk, if there is one */ - -static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p) -{ - bit++; - while (bit < BM_BITS_PER_CHUNK) { - if (test_bit(bit, chunk_p)) - return bit; - - bit++; - } - return -1; -} - -/* Find a chunk containing some bits set in given block of bits */ - -static inline int next_chunk_in_block(int n, struct bm_block *bb) -{ - n++; - while (n < bb->size) { - if (bb->data[n]) - return n; - - n++; - } - return -1; -} - /** * memory_bm_next_pfn - find the pfn that corresponds to the next set bit * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is @@ -571,40 +532,33 @@ static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) { struct zone_bitmap *zone_bm; struct bm_block *bb; - int chunk; int bit; do { bb = bm->cur.block; do { - chunk = bm->cur.chunk; bit = bm->cur.bit; - do { - bit = next_bit_in_chunk(bit, bb->data + chunk); - if (bit >= 0) - goto Return_pfn; - - chunk = next_chunk_in_block(chunk, bb); - bit = -1; - } while (chunk >= 0); + bit = find_next_bit(bb->data, bm_block_bits(bb), bit); + if (bit < bm_block_bits(bb)) + goto Return_pfn; + bb = bb->next; bm->cur.block = bb; - memory_bm_reset_chunk(bm); + bm->cur.bit = 0; } while (bb); zone_bm = bm->cur.zone_bm->next; if (zone_bm) { bm->cur.zone_bm = zone_bm; bm->cur.block = zone_bm->bm_blocks; - memory_bm_reset_chunk(bm); + bm->cur.bit = 0; } } while (zone_bm); memory_bm_position_reset(bm); return BM_END_OF_MAP; Return_pfn: - bm->cur.chunk = chunk; - bm->cur.bit = bit; - return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit; + bm->cur.bit = bit + 1; + return bb->start_pfn + bit; } /** diff --git a/kernel/power/swap.c b/kernel/power/swap.c index a0abf9a..80ccac8 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -14,7 +14,6 @@ #include <linux/module.h> #include <linux/file.h> #include <linux/utsname.h> -#include <linux/version.h> #include <linux/delay.h> #include <linux/bitops.h> #include <linux/genhd.h> diff --git a/kernel/power/user.c b/kernel/power/user.c index f5512cb..a6332a3 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -23,6 +23,7 @@ #include <linux/console.h> #include <linux/cpu.h> #include <linux/freezer.h> +#include <linux/smp_lock.h> #include <asm/uaccess.h> @@ -69,16 +70,22 @@ static int snapshot_open(struct inode *inode, struct file *filp) struct snapshot_data *data; int error; - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) - return -EBUSY; + mutex_lock(&pm_mutex); + + if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { + error = -EBUSY; + goto Unlock; + } if ((filp->f_flags & O_ACCMODE) == O_RDWR) { atomic_inc(&snapshot_device_available); - return -ENOSYS; + error = -ENOSYS; + goto Unlock; } if(create_basic_memory_bitmaps()) { atomic_inc(&snapshot_device_available); - return -ENOMEM; + error = -ENOMEM; + goto Unlock; } nonseekable_open(inode, filp); data = &snapshot_state; @@ -98,33 +105,36 @@ static int snapshot_open(struct inode *inode, struct file *filp) if (error) pm_notifier_call_chain(PM_POST_HIBERNATION); } - if (error) { + if (error) atomic_inc(&snapshot_device_available); - return error; - } data->frozen = 0; data->ready = 0; data->platform_support = 0; - return 0; + Unlock: + mutex_unlock(&pm_mutex); + + return error; } static int snapshot_release(struct inode *inode, struct file *filp) { struct snapshot_data *data; + mutex_lock(&pm_mutex); + swsusp_free(); free_basic_memory_bitmaps(); data = filp->private_data; free_all_swap_pages(data->swap); - if (data->frozen) { - mutex_lock(&pm_mutex); + if (data->frozen) thaw_processes(); - mutex_unlock(&pm_mutex); - } pm_notifier_call_chain(data->mode == O_WRONLY ? PM_POST_HIBERNATION : PM_POST_RESTORE); atomic_inc(&snapshot_device_available); + + mutex_unlock(&pm_mutex); + return 0; } @@ -134,9 +144,13 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf, struct snapshot_data *data; ssize_t res; + mutex_lock(&pm_mutex); + data = filp->private_data; - if (!data->ready) - return -ENODATA; + if (!data->ready) { + res = -ENODATA; + goto Unlock; + } res = snapshot_read_next(&data->handle, count); if (res > 0) { if (copy_to_user(buf, data_of(data->handle), res)) @@ -144,6 +158,10 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf, else *offp = data->handle.offset; } + + Unlock: + mutex_unlock(&pm_mutex); + return res; } @@ -153,6 +171,8 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, struct snapshot_data *data; ssize_t res; + mutex_lock(&pm_mutex); + data = filp->private_data; res = snapshot_write_next(&data->handle, count); if (res > 0) { @@ -161,11 +181,14 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, else *offp = data->handle.offset; } + + mutex_unlock(&pm_mutex); + return res; } -static int snapshot_ioctl(struct inode *inode, struct file *filp, - unsigned int cmd, unsigned long arg) +static long snapshot_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) { int error = 0; struct snapshot_data *data; @@ -179,6 +202,9 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (!mutex_trylock(&pm_mutex)) + return -EBUSY; + data = filp->private_data; switch (cmd) { @@ -186,7 +212,6 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, case SNAPSHOT_FREEZE: if (data->frozen) break; - mutex_lock(&pm_mutex); printk("Syncing filesystems ... "); sys_sync(); printk("done.\n"); @@ -194,7 +219,6 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, error = freeze_processes(); if (error) thaw_processes(); - mutex_unlock(&pm_mutex); if (!error) data->frozen = 1; break; @@ -202,9 +226,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, case SNAPSHOT_UNFREEZE: if (!data->frozen || data->ready) break; - mutex_lock(&pm_mutex); thaw_processes(); - mutex_unlock(&pm_mutex); data->frozen = 0; break; @@ -307,16 +329,11 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, error = -EPERM; break; } - if (!mutex_trylock(&pm_mutex)) { - error = -EBUSY; - break; - } /* * Tasks are frozen and the notifiers have been called with * PM_HIBERNATION_PREPARE */ error = suspend_devices_and_enter(PM_SUSPEND_MEM); - mutex_unlock(&pm_mutex); break; case SNAPSHOT_PLATFORM_SUPPORT: @@ -390,6 +407,8 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, } + mutex_unlock(&pm_mutex); + return error; } @@ -399,7 +418,7 @@ static const struct file_operations snapshot_fops = { .read = snapshot_read, .write = snapshot_write, .llseek = no_llseek, - .ioctl = snapshot_ioctl, + .unlocked_ioctl = snapshot_ioctl, }; static struct miscdevice snapshot_device = { diff --git a/kernel/printk.c b/kernel/printk.c index 8fb01c3..a430fd0 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -38,7 +38,7 @@ /* * Architectures can override it: */ -void __attribute__((weak)) early_printk(const char *fmt, ...) +void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...) { } @@ -75,6 +75,8 @@ EXPORT_SYMBOL(oops_in_progress); static DECLARE_MUTEX(console_sem); static DECLARE_MUTEX(secondary_console_sem); struct console *console_drivers; +EXPORT_SYMBOL_GPL(console_drivers); + /* * This is used for debugging the mess that is the VT code by * keeping track if we have the console semaphore held. It's @@ -121,6 +123,8 @@ struct console_cmdline static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES]; static int selected_console = -1; static int preferred_console = -1; +int console_set_on_cmdline; +EXPORT_SYMBOL(console_set_on_cmdline); /* Flag: console code may call schedule() */ static int console_may_schedule; @@ -231,7 +235,7 @@ static inline void boot_delay_msec(void) /* * Return the number of unread characters in the log buffer. */ -int log_buf_get_len(void) +static int log_buf_get_len(void) { return logged_chars; } @@ -268,19 +272,6 @@ int log_buf_copy(char *dest, int idx, int len) } /* - * Extract a single character from the log buffer. - */ -int log_buf_read(int idx) -{ - char ret; - - if (log_buf_copy(&ret, idx, 1) == 1) - return ret; - else - return -1; -} - -/* * Commands to do_syslog: * * 0 -- Close the log. Currently a NOP. @@ -665,18 +656,17 @@ static int acquire_console_semaphore_for_printk(unsigned int cpu) spin_unlock(&logbuf_lock); return retval; } - -const char printk_recursion_bug_msg [] = - KERN_CRIT "BUG: recent printk recursion!\n"; -static int printk_recursion_bug; +static const char recursion_bug_msg [] = + KERN_CRIT "BUG: recent printk recursion!\n"; +static int recursion_bug; + static int new_text_line = 1; +static char printk_buf[1024]; asmlinkage int vprintk(const char *fmt, va_list args) { - static int log_level_unknown = 1; - static char printk_buf[1024]; - - unsigned long flags; int printed_len = 0; + int current_log_level = default_message_loglevel; + unsigned long flags; int this_cpu; char *p; @@ -699,7 +689,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * it can be printed at the next appropriate moment: */ if (!oops_in_progress) { - printk_recursion_bug = 1; + recursion_bug = 1; goto out_restore_irqs; } zap_locks(); @@ -709,70 +699,62 @@ asmlinkage int vprintk(const char *fmt, va_list args) spin_lock(&logbuf_lock); printk_cpu = this_cpu; - if (printk_recursion_bug) { - printk_recursion_bug = 0; - strcpy(printk_buf, printk_recursion_bug_msg); - printed_len = sizeof(printk_recursion_bug_msg); + if (recursion_bug) { + recursion_bug = 0; + strcpy(printk_buf, recursion_bug_msg); + printed_len = sizeof(recursion_bug_msg); } /* Emit the output into the temporary buffer */ printed_len += vscnprintf(printk_buf + printed_len, sizeof(printk_buf) - printed_len, fmt, args); + /* * Copy the output into log_buf. If the caller didn't provide * appropriate log level tags, we insert them here */ for (p = printk_buf; *p; p++) { - if (log_level_unknown) { - /* log_level_unknown signals the start of a new line */ + if (new_text_line) { + /* If a token, set current_log_level and skip over */ + if (p[0] == '<' && p[1] >= '0' && p[1] <= '7' && + p[2] == '>') { + current_log_level = p[1] - '0'; + p += 3; + printed_len -= 3; + } + + /* Always output the token */ + emit_log_char('<'); + emit_log_char(current_log_level + '0'); + emit_log_char('>'); + printed_len += 3; + new_text_line = 0; + if (printk_time) { - int loglev_char; + /* Follow the token with the time */ char tbuf[50], *tp; unsigned tlen; unsigned long long t; unsigned long nanosec_rem; - /* - * force the log level token to be - * before the time output. - */ - if (p[0] == '<' && p[1] >='0' && - p[1] <= '7' && p[2] == '>') { - loglev_char = p[1]; - p += 3; - printed_len -= 3; - } else { - loglev_char = default_message_loglevel - + '0'; - } t = cpu_clock(printk_cpu); nanosec_rem = do_div(t, 1000000000); - tlen = sprintf(tbuf, - "<%c>[%5lu.%06lu] ", - loglev_char, - (unsigned long)t, - nanosec_rem/1000); + tlen = sprintf(tbuf, "[%5lu.%06lu] ", + (unsigned long) t, + nanosec_rem / 1000); for (tp = tbuf; tp < tbuf + tlen; tp++) emit_log_char(*tp); printed_len += tlen; - } else { - if (p[0] != '<' || p[1] < '0' || - p[1] > '7' || p[2] != '>') { - emit_log_char('<'); - emit_log_char(default_message_loglevel - + '0'); - emit_log_char('>'); - printed_len += 3; - } } - log_level_unknown = 0; + if (!*p) break; } + emit_log_char(*p); if (*p == '\n') - log_level_unknown = 1; + new_text_line = 1; } /* @@ -890,6 +872,7 @@ static int __init console_setup(char *str) *s = 0; __add_preferred_console(buf, idx, options, brl_options); + console_set_on_cmdline = 1; return 1; } __setup("console=", console_setup); @@ -950,7 +933,7 @@ void suspend_console(void) { if (!console_suspend_enabled) return; - printk("Suspending console(s)\n"); + printk("Suspending console(s) (use no_console_suspend to debug)\n"); acquire_console_sem(); console_suspended = 1; } @@ -1041,7 +1024,9 @@ void release_console_sem(void) _log_end = log_end; con_start = log_end; /* Flush */ spin_unlock(&logbuf_lock); + stop_critical_timings(); /* don't trace print latency */ call_console_drivers(_con_start, _log_end); + start_critical_timings(); local_irq_restore(flags); } console_locked = 0; @@ -1172,8 +1157,11 @@ void register_console(struct console *console) console->index = 0; if (console->setup == NULL || console->setup(console, NULL) == 0) { - console->flags |= CON_ENABLED | CON_CONSDEV; - preferred_console = 0; + console->flags |= CON_ENABLED; + if (console->device) { + console->flags |= CON_CONSDEV; + preferred_console = 0; + } } } @@ -1303,46 +1291,19 @@ static int __init disable_boot_consoles(void) } late_initcall(disable_boot_consoles); -/** - * tty_write_message - write a message to a certain tty, not just the console. - * @tty: the destination tty_struct - * @msg: the message to write - * - * This is used for messages that need to be redirected to a specific tty. - * We don't put it into the syslog queue right now maybe in the future if - * really needed. - */ -void tty_write_message(struct tty_struct *tty, char *msg) -{ - if (tty && tty->ops->write) - tty->ops->write(tty, msg, strlen(msg)); - return; -} - #if defined CONFIG_PRINTK + /* * printk rate limiting, lifted from the networking subsystem. * - * This enforces a rate limit: not more than one kernel message - * every printk_ratelimit_jiffies to make a denial-of-service - * attack impossible. + * This enforces a rate limit: not more than 10 kernel messages + * every 5s to make a denial-of-service attack impossible. */ -int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) -{ - return __ratelimit(ratelimit_jiffies, ratelimit_burst); -} -EXPORT_SYMBOL(__printk_ratelimit); - -/* minimum time in jiffies between messages */ -int printk_ratelimit_jiffies = 5 * HZ; - -/* number of messages we send before ratelimiting */ -int printk_ratelimit_burst = 10; +DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10); int printk_ratelimit(void) { - return __printk_ratelimit(printk_ratelimit_jiffies, - printk_ratelimit_burst); + return __ratelimit(&printk_ratelimit_state); } EXPORT_SYMBOL(printk_ratelimit); diff --git a/kernel/profile.c b/kernel/profile.c index ae7ead8..cd26bed 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -112,8 +112,6 @@ void __init profile_init(void) /* Profile event notifications */ -#ifdef CONFIG_PROFILING - static BLOCKING_NOTIFIER_HEAD(task_exit_notifier); static ATOMIC_NOTIFIER_HEAD(task_free_notifier); static BLOCKING_NOTIFIER_HEAD(munmap_notifier); @@ -203,8 +201,6 @@ void unregister_timer_hook(int (*hook)(struct pt_regs *)) } EXPORT_SYMBOL_GPL(unregister_timer_hook); -#endif /* CONFIG_PROFILING */ - #ifdef CONFIG_SMP /* @@ -252,7 +248,7 @@ static void profile_flip_buffers(void) mutex_lock(&profile_flip_mutex); j = per_cpu(cpu_profile_flip, get_cpu()); put_cpu(); - on_each_cpu(__profile_flip_buffers, NULL, 0, 1); + on_each_cpu(__profile_flip_buffers, NULL, 1); for_each_online_cpu(cpu) { struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; for (i = 0; i < NR_PROFILE_HIT; ++i) { @@ -275,7 +271,7 @@ static void profile_discard_flip_buffers(void) mutex_lock(&profile_flip_mutex); i = per_cpu(cpu_profile_flip, get_cpu()); put_cpu(); - on_each_cpu(__profile_flip_buffers, NULL, 0, 1); + on_each_cpu(__profile_flip_buffers, NULL, 1); for_each_online_cpu(cpu) { struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); @@ -558,7 +554,7 @@ static int __init create_hash_tables(void) out_cleanup: prof_on = 0; smp_mb(); - on_each_cpu(profile_nop, NULL, 0, 1); + on_each_cpu(profile_nop, NULL, 1); for_each_online_cpu(cpu) { struct page *page; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 6c19e94..356699a 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -33,13 +33,9 @@ */ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) { - BUG_ON(!list_empty(&child->ptrace_list)); - if (child->parent == new_parent) - return; - list_add(&child->ptrace_list, &child->parent->ptrace_children); - remove_parent(child); + BUG_ON(!list_empty(&child->ptrace_entry)); + list_add(&child->ptrace_entry, &new_parent->ptraced); child->parent = new_parent; - add_parent(child); } /* @@ -73,12 +69,8 @@ void __ptrace_unlink(struct task_struct *child) BUG_ON(!child->ptrace); child->ptrace = 0; - if (ptrace_reparented(child)) { - list_del_init(&child->ptrace_list); - remove_parent(child); - child->parent = child->real_parent; - add_parent(child); - } + child->parent = child->real_parent; + list_del_init(&child->ptrace_entry); if (task_is_traced(child)) ptrace_untrace(child); @@ -115,13 +107,13 @@ int ptrace_check_attach(struct task_struct *child, int kill) read_unlock(&tasklist_lock); if (!ret && !kill) - wait_task_inactive(child); + ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; /* All systems go.. */ return ret; } -int __ptrace_may_attach(struct task_struct *task) +int __ptrace_may_access(struct task_struct *task, unsigned int mode) { /* May we inspect the given task? * This check is used both for attaching with ptrace @@ -148,16 +140,16 @@ int __ptrace_may_attach(struct task_struct *task) if (!dumpable && !capable(CAP_SYS_PTRACE)) return -EPERM; - return security_ptrace(current, task); + return security_ptrace_may_access(task, mode); } -int ptrace_may_attach(struct task_struct *task) +bool ptrace_may_access(struct task_struct *task, unsigned int mode) { int err; task_lock(task); - err = __ptrace_may_attach(task); + err = __ptrace_may_access(task, mode); task_unlock(task); - return !err; + return (!err ? true : false); } int ptrace_attach(struct task_struct *task) @@ -195,7 +187,7 @@ repeat: /* the same process cannot be attached many times */ if (task->ptrace & PT_PTRACED) goto bad; - retval = __ptrace_may_attach(task); + retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); if (retval) goto bad; @@ -492,14 +484,33 @@ int ptrace_traceme(void) /* * Are we already being traced? */ +repeat: task_lock(current); if (!(current->ptrace & PT_PTRACED)) { - ret = security_ptrace(current->parent, current); + /* + * See ptrace_attach() comments about the locking here. + */ + unsigned long flags; + if (!write_trylock_irqsave(&tasklist_lock, flags)) { + task_unlock(current); + do { + cpu_relax(); + } while (!write_can_lock(&tasklist_lock)); + goto repeat; + } + + ret = security_ptrace_traceme(current->parent); + /* * Set the ptrace bit in the process ptrace flags. + * Then link us on our parent's ptraced list. */ - if (!ret) + if (!ret) { current->ptrace |= PT_PTRACED; + __ptrace_link(current, current->real_parent); + } + + write_unlock_irqrestore(&tasklist_lock, flags); } task_unlock(current); return ret; diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c index f4ffbd0..37f72e551 100644 --- a/kernel/rcuclassic.c +++ b/kernel/rcuclassic.c @@ -47,6 +47,7 @@ #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/mutex.h> +#include <linux/time.h> #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key rcu_lock_key; @@ -60,12 +61,14 @@ EXPORT_SYMBOL_GPL(rcu_lock_map); static struct rcu_ctrlblk rcu_ctrlblk = { .cur = -300, .completed = -300, + .pending = -300, .lock = __SPIN_LOCK_UNLOCKED(&rcu_ctrlblk.lock), .cpumask = CPU_MASK_NONE, }; static struct rcu_ctrlblk rcu_bh_ctrlblk = { .cur = -300, .completed = -300, + .pending = -300, .lock = __SPIN_LOCK_UNLOCKED(&rcu_bh_ctrlblk.lock), .cpumask = CPU_MASK_NONE, }; @@ -83,18 +86,36 @@ static void force_quiescent_state(struct rcu_data *rdp, { int cpu; cpumask_t cpumask; + unsigned long flags; + set_need_resched(); + spin_lock_irqsave(&rcp->lock, flags); if (unlikely(!rcp->signaled)) { rcp->signaled = 1; /* * Don't send IPI to itself. With irqs disabled, * rdp->cpu is the current cpu. + * + * cpu_online_map is updated by the _cpu_down() + * using __stop_machine(). Since we're in irqs disabled + * section, __stop_machine() is not exectuting, hence + * the cpu_online_map is stable. + * + * However, a cpu might have been offlined _just_ before + * we disabled irqs while entering here. + * And rcu subsystem might not yet have handled the CPU_DEAD + * notification, leading to the offlined cpu's bit + * being set in the rcp->cpumask. + * + * Hence cpumask = (rcp->cpumask & cpu_online_map) to prevent + * sending smp_reschedule() to an offlined CPU. */ - cpumask = rcp->cpumask; + cpus_and(cpumask, rcp->cpumask, cpu_online_map); cpu_clear(rdp->cpu, cpumask); - for_each_cpu_mask(cpu, cpumask) + for_each_cpu_mask_nr(cpu, cpumask) smp_send_reschedule(cpu); } + spin_unlock_irqrestore(&rcp->lock, flags); } #else static inline void force_quiescent_state(struct rcu_data *rdp, @@ -104,6 +125,126 @@ static inline void force_quiescent_state(struct rcu_data *rdp, } #endif +static void __call_rcu(struct rcu_head *head, struct rcu_ctrlblk *rcp, + struct rcu_data *rdp) +{ + long batch; + + head->next = NULL; + smp_mb(); /* Read of rcu->cur must happen after any change by caller. */ + + /* + * Determine the batch number of this callback. + * + * Using ACCESS_ONCE to avoid the following error when gcc eliminates + * local variable "batch" and emits codes like this: + * 1) rdp->batch = rcp->cur + 1 # gets old value + * ...... + * 2)rcu_batch_after(rcp->cur + 1, rdp->batch) # gets new value + * then [*nxttail[0], *nxttail[1]) may contain callbacks + * that batch# = rdp->batch, see the comment of struct rcu_data. + */ + batch = ACCESS_ONCE(rcp->cur) + 1; + + if (rdp->nxtlist && rcu_batch_after(batch, rdp->batch)) { + /* process callbacks */ + rdp->nxttail[0] = rdp->nxttail[1]; + rdp->nxttail[1] = rdp->nxttail[2]; + if (rcu_batch_after(batch - 1, rdp->batch)) + rdp->nxttail[0] = rdp->nxttail[2]; + } + + rdp->batch = batch; + *rdp->nxttail[2] = head; + rdp->nxttail[2] = &head->next; + + if (unlikely(++rdp->qlen > qhimark)) { + rdp->blimit = INT_MAX; + force_quiescent_state(rdp, &rcu_ctrlblk); + } +} + +#ifdef CONFIG_RCU_CPU_STALL_DETECTOR + +static void record_gp_stall_check_time(struct rcu_ctrlblk *rcp) +{ + rcp->gp_start = jiffies; + rcp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_CHECK; +} + +static void print_other_cpu_stall(struct rcu_ctrlblk *rcp) +{ + int cpu; + long delta; + unsigned long flags; + + /* Only let one CPU complain about others per time interval. */ + + spin_lock_irqsave(&rcp->lock, flags); + delta = jiffies - rcp->jiffies_stall; + if (delta < 2 || rcp->cur != rcp->completed) { + spin_unlock_irqrestore(&rcp->lock, flags); + return; + } + rcp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK; + spin_unlock_irqrestore(&rcp->lock, flags); + + /* OK, time to rat on our buddy... */ + + printk(KERN_ERR "RCU detected CPU stalls:"); + for_each_possible_cpu(cpu) { + if (cpu_isset(cpu, rcp->cpumask)) + printk(" %d", cpu); + } + printk(" (detected by %d, t=%ld jiffies)\n", + smp_processor_id(), (long)(jiffies - rcp->gp_start)); +} + +static void print_cpu_stall(struct rcu_ctrlblk *rcp) +{ + unsigned long flags; + + printk(KERN_ERR "RCU detected CPU %d stall (t=%lu/%lu jiffies)\n", + smp_processor_id(), jiffies, + jiffies - rcp->gp_start); + dump_stack(); + spin_lock_irqsave(&rcp->lock, flags); + if ((long)(jiffies - rcp->jiffies_stall) >= 0) + rcp->jiffies_stall = + jiffies + RCU_SECONDS_TILL_STALL_RECHECK; + spin_unlock_irqrestore(&rcp->lock, flags); + set_need_resched(); /* kick ourselves to get things going. */ +} + +static void check_cpu_stall(struct rcu_ctrlblk *rcp) +{ + long delta; + + delta = jiffies - rcp->jiffies_stall; + if (cpu_isset(smp_processor_id(), rcp->cpumask) && delta >= 0) { + + /* We haven't checked in, so go dump stack. */ + print_cpu_stall(rcp); + + } else if (rcp->cur != rcp->completed && delta >= 2) { + + /* They had two seconds to dump stack, so complain. */ + print_other_cpu_stall(rcp); + } +} + +#else /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ + +static void record_gp_stall_check_time(struct rcu_ctrlblk *rcp) +{ +} + +static inline void check_cpu_stall(struct rcu_ctrlblk *rcp) +{ +} + +#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ + /** * call_rcu - Queue an RCU callback for invocation after a grace period. * @head: structure to be used for queueing the RCU updates. @@ -119,18 +260,10 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) { unsigned long flags; - struct rcu_data *rdp; head->func = func; - head->next = NULL; local_irq_save(flags); - rdp = &__get_cpu_var(rcu_data); - *rdp->nxttail = head; - rdp->nxttail = &head->next; - if (unlikely(++rdp->qlen > qhimark)) { - rdp->blimit = INT_MAX; - force_quiescent_state(rdp, &rcu_ctrlblk); - } + __call_rcu(head, &rcu_ctrlblk, &__get_cpu_var(rcu_data)); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(call_rcu); @@ -155,20 +288,10 @@ void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) { unsigned long flags; - struct rcu_data *rdp; head->func = func; - head->next = NULL; local_irq_save(flags); - rdp = &__get_cpu_var(rcu_bh_data); - *rdp->nxttail = head; - rdp->nxttail = &head->next; - - if (unlikely(++rdp->qlen > qhimark)) { - rdp->blimit = INT_MAX; - force_quiescent_state(rdp, &rcu_bh_ctrlblk); - } - + __call_rcu(head, &rcu_bh_ctrlblk, &__get_cpu_var(rcu_bh_data)); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(call_rcu_bh); @@ -197,12 +320,6 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed_bh); static inline void raise_rcu_softirq(void) { raise_softirq(RCU_SOFTIRQ); - /* - * The smp_mb() here is required to ensure that this cpu's - * __rcu_process_callbacks() reads the most recently updated - * value of rcu->cur. - */ - smp_mb(); } /* @@ -211,6 +328,7 @@ static inline void raise_rcu_softirq(void) */ static void rcu_do_batch(struct rcu_data *rdp) { + unsigned long flags; struct rcu_head *next, *list; int count = 0; @@ -225,9 +343,9 @@ static void rcu_do_batch(struct rcu_data *rdp) } rdp->donelist = list; - local_irq_disable(); + local_irq_save(flags); rdp->qlen -= count; - local_irq_enable(); + local_irq_restore(flags); if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark) rdp->blimit = blimit; @@ -255,6 +373,7 @@ static void rcu_do_batch(struct rcu_data *rdp) * rcu_check_quiescent_state calls rcu_start_batch(0) to start the next grace * period (if necessary). */ + /* * Register a new batch of callbacks, and start it up if there is currently no * active batch and the batch to be registered has not already occurred. @@ -262,15 +381,10 @@ static void rcu_do_batch(struct rcu_data *rdp) */ static void rcu_start_batch(struct rcu_ctrlblk *rcp) { - if (rcp->next_pending && + if (rcp->cur != rcp->pending && rcp->completed == rcp->cur) { - rcp->next_pending = 0; - /* - * next_pending == 0 must be visible in - * __rcu_process_callbacks() before it can see new value of cur. - */ - smp_wmb(); rcp->cur++; + record_gp_stall_check_time(rcp); /* * Accessing nohz_cpu_mask before incrementing rcp->cur needs a @@ -308,6 +422,8 @@ static void cpu_quiet(int cpu, struct rcu_ctrlblk *rcp) static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, struct rcu_data *rdp) { + unsigned long flags; + if (rdp->quiescbatch != rcp->cur) { /* start new grace period: */ rdp->qs_pending = 1; @@ -331,7 +447,7 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, return; rdp->qs_pending = 0; - spin_lock(&rcp->lock); + spin_lock_irqsave(&rcp->lock, flags); /* * rdp->quiescbatch/rcp->cur and the cpu bitmap can come out of sync * during cpu startup. Ignore the quiescent state. @@ -339,7 +455,7 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, if (likely(rdp->quiescbatch == rcp->cur)) cpu_quiet(rdp->cpu, rcp); - spin_unlock(&rcp->lock); + spin_unlock_irqrestore(&rcp->lock, flags); } @@ -350,29 +466,38 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp, * which is dead and hence not processing interrupts. */ static void rcu_move_batch(struct rcu_data *this_rdp, struct rcu_head *list, - struct rcu_head **tail) + struct rcu_head **tail, long batch) { - local_irq_disable(); - *this_rdp->nxttail = list; - if (list) - this_rdp->nxttail = tail; - local_irq_enable(); + unsigned long flags; + + if (list) { + local_irq_save(flags); + this_rdp->batch = batch; + *this_rdp->nxttail[2] = list; + this_rdp->nxttail[2] = tail; + local_irq_restore(flags); + } } static void __rcu_offline_cpu(struct rcu_data *this_rdp, struct rcu_ctrlblk *rcp, struct rcu_data *rdp) { - /* if the cpu going offline owns the grace period + unsigned long flags; + + /* + * if the cpu going offline owns the grace period * we can block indefinitely waiting for it, so flush * it here */ - spin_lock_bh(&rcp->lock); + spin_lock_irqsave(&rcp->lock, flags); if (rcp->cur != rcp->completed) cpu_quiet(rdp->cpu, rcp); - spin_unlock_bh(&rcp->lock); - rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail); - rcu_move_batch(this_rdp, rdp->curlist, rdp->curtail); - rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail); + rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail, rcp->cur + 1); + rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail[2], rcp->cur + 1); + spin_unlock(&rcp->lock); + + this_rdp->qlen += rdp->qlen; + local_irq_restore(flags); } static void rcu_offline_cpu(int cpu) @@ -402,38 +527,52 @@ static void rcu_offline_cpu(int cpu) static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp, struct rcu_data *rdp) { - if (rdp->curlist && !rcu_batch_before(rcp->completed, rdp->batch)) { - *rdp->donetail = rdp->curlist; - rdp->donetail = rdp->curtail; - rdp->curlist = NULL; - rdp->curtail = &rdp->curlist; - } + unsigned long flags; + long completed_snap; - if (rdp->nxtlist && !rdp->curlist) { - local_irq_disable(); - rdp->curlist = rdp->nxtlist; - rdp->curtail = rdp->nxttail; - rdp->nxtlist = NULL; - rdp->nxttail = &rdp->nxtlist; - local_irq_enable(); + if (rdp->nxtlist) { + local_irq_save(flags); + completed_snap = ACCESS_ONCE(rcp->completed); /* - * start the next batch of callbacks + * move the other grace-period-completed entries to + * [rdp->nxtlist, *rdp->nxttail[0]) temporarily */ + if (!rcu_batch_before(completed_snap, rdp->batch)) + rdp->nxttail[0] = rdp->nxttail[1] = rdp->nxttail[2]; + else if (!rcu_batch_before(completed_snap, rdp->batch - 1)) + rdp->nxttail[0] = rdp->nxttail[1]; - /* determine batch number */ - rdp->batch = rcp->cur + 1; - /* see the comment and corresponding wmb() in - * the rcu_start_batch() + /* + * the grace period for entries in + * [rdp->nxtlist, *rdp->nxttail[0]) has completed and + * move these entries to donelist */ - smp_rmb(); + if (rdp->nxttail[0] != &rdp->nxtlist) { + *rdp->donetail = rdp->nxtlist; + rdp->donetail = rdp->nxttail[0]; + rdp->nxtlist = *rdp->nxttail[0]; + *rdp->donetail = NULL; + + if (rdp->nxttail[1] == rdp->nxttail[0]) + rdp->nxttail[1] = &rdp->nxtlist; + if (rdp->nxttail[2] == rdp->nxttail[0]) + rdp->nxttail[2] = &rdp->nxtlist; + rdp->nxttail[0] = &rdp->nxtlist; + } + + local_irq_restore(flags); + + if (rcu_batch_after(rdp->batch, rcp->pending)) { + unsigned long flags2; - if (!rcp->next_pending) { /* and start it/schedule start if it's a new batch */ - spin_lock(&rcp->lock); - rcp->next_pending = 1; - rcu_start_batch(rcp); - spin_unlock(&rcp->lock); + spin_lock_irqsave(&rcp->lock, flags2); + if (rcu_batch_after(rdp->batch, rcp->pending)) { + rcp->pending = rdp->batch; + rcu_start_batch(rcp); + } + spin_unlock_irqrestore(&rcp->lock, flags2); } } @@ -444,21 +583,53 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp, static void rcu_process_callbacks(struct softirq_action *unused) { + /* + * Memory references from any prior RCU read-side critical sections + * executed by the interrupted code must be see before any RCU + * grace-period manupulations below. + */ + + smp_mb(); /* See above block comment. */ + __rcu_process_callbacks(&rcu_ctrlblk, &__get_cpu_var(rcu_data)); __rcu_process_callbacks(&rcu_bh_ctrlblk, &__get_cpu_var(rcu_bh_data)); + + /* + * Memory references from any later RCU read-side critical sections + * executed by the interrupted code must be see after any RCU + * grace-period manupulations above. + */ + + smp_mb(); /* See above block comment. */ } static int __rcu_pending(struct rcu_ctrlblk *rcp, struct rcu_data *rdp) { - /* This cpu has pending rcu entries and the grace period - * for them has completed. - */ - if (rdp->curlist && !rcu_batch_before(rcp->completed, rdp->batch)) - return 1; + /* Check for CPU stalls, if enabled. */ + check_cpu_stall(rcp); - /* This cpu has no pending entries, but there are new entries */ - if (!rdp->curlist && rdp->nxtlist) - return 1; + if (rdp->nxtlist) { + long completed_snap = ACCESS_ONCE(rcp->completed); + + /* + * This cpu has pending rcu entries and the grace period + * for them has completed. + */ + if (!rcu_batch_before(completed_snap, rdp->batch)) + return 1; + if (!rcu_batch_before(completed_snap, rdp->batch - 1) && + rdp->nxttail[0] != rdp->nxttail[1]) + return 1; + if (rdp->nxttail[0] != &rdp->nxtlist) + return 1; + + /* + * This cpu has pending rcu entries and the new batch + * for then hasn't been started nor scheduled start + */ + if (rcu_batch_after(rdp->batch, rcp->pending)) + return 1; + } /* This cpu has finished callbacks to invoke */ if (rdp->donelist) @@ -494,32 +665,69 @@ int rcu_needs_cpu(int cpu) struct rcu_data *rdp = &per_cpu(rcu_data, cpu); struct rcu_data *rdp_bh = &per_cpu(rcu_bh_data, cpu); - return (!!rdp->curlist || !!rdp_bh->curlist || rcu_pending(cpu)); + return !!rdp->nxtlist || !!rdp_bh->nxtlist || rcu_pending(cpu); } +/* + * Top-level function driving RCU grace-period detection, normally + * invoked from the scheduler-clock interrupt. This function simply + * increments counters that are read only from softirq by this same + * CPU, so there are no memory barriers required. + */ void rcu_check_callbacks(int cpu, int user) { if (user || (idle_cpu(cpu) && !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) { + + /* + * Get here if this CPU took its interrupt from user + * mode or from the idle loop, and if this is not a + * nested interrupt. In this case, the CPU is in + * a quiescent state, so count it. + * + * Also do a memory barrier. This is needed to handle + * the case where writes from a preempt-disable section + * of code get reordered into schedule() by this CPU's + * write buffer. The memory barrier makes sure that + * the rcu_qsctr_inc() and rcu_bh_qsctr_inc() are see + * by other CPUs to happen after any such write. + */ + + smp_mb(); /* See above block comment. */ rcu_qsctr_inc(cpu); rcu_bh_qsctr_inc(cpu); - } else if (!in_softirq()) + + } else if (!in_softirq()) { + + /* + * Get here if this CPU did not take its interrupt from + * softirq, in other words, if it is not interrupting + * a rcu_bh read-side critical section. This is an _bh + * critical section, so count it. The memory barrier + * is needed for the same reason as is the above one. + */ + + smp_mb(); /* See above block comment. */ rcu_bh_qsctr_inc(cpu); + } raise_rcu_softirq(); } static void rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp, struct rcu_data *rdp) { + unsigned long flags; + + spin_lock_irqsave(&rcp->lock, flags); memset(rdp, 0, sizeof(*rdp)); - rdp->curtail = &rdp->curlist; - rdp->nxttail = &rdp->nxtlist; + rdp->nxttail[0] = rdp->nxttail[1] = rdp->nxttail[2] = &rdp->nxtlist; rdp->donetail = &rdp->donelist; rdp->quiescbatch = rcp->completed; rdp->qs_pending = 0; rdp->cpu = cpu; rdp->blimit = blimit; + spin_unlock_irqrestore(&rcp->lock, flags); } static void __cpuinit rcu_online_cpu(int cpu) @@ -529,7 +737,7 @@ static void __cpuinit rcu_online_cpu(int cpu) rcu_init_percpu_data(cpu, &rcu_ctrlblk, rdp); rcu_init_percpu_data(cpu, &rcu_bh_ctrlblk, bh_rdp); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } static int __cpuinit rcu_cpu_notify(struct notifier_block *self, @@ -564,6 +772,9 @@ static struct notifier_block __cpuinitdata rcu_nb = { */ void __init __rcu_init(void) { +#ifdef CONFIG_RCU_CPU_STALL_DETECTOR + printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n"); +#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long)smp_processor_id()); /* Register notifier for non-boot CPUs */ diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index c09605f..467d594 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -39,16 +39,16 @@ #include <linux/sched.h> #include <asm/atomic.h> #include <linux/bitops.h> -#include <linux/completion.h> #include <linux/percpu.h> #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/module.h> -struct rcu_synchronize { - struct rcu_head head; - struct completion completion; +enum rcu_barrier { + RCU_BARRIER_STD, + RCU_BARRIER_BH, + RCU_BARRIER_SCHED, }; static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL}; @@ -60,7 +60,7 @@ static struct completion rcu_barrier_completion; * Awaken the corresponding synchronize_rcu() instance now that a * grace period has elapsed. */ -static void wakeme_after_rcu(struct rcu_head *head) +void wakeme_after_rcu(struct rcu_head *head) { struct rcu_synchronize *rcu; @@ -77,17 +77,8 @@ static void wakeme_after_rcu(struct rcu_head *head) * sections are delimited by rcu_read_lock() and rcu_read_unlock(), * and may be nested. */ -void synchronize_rcu(void) -{ - struct rcu_synchronize rcu; - - init_completion(&rcu.completion); - /* Will wake me after RCU finished */ - call_rcu(&rcu.head, wakeme_after_rcu); - - /* Wait for it */ - wait_for_completion(&rcu.completion); -} +void synchronize_rcu(void); /* Makes kernel-doc tools happy */ +synchronize_rcu_xxx(synchronize_rcu, call_rcu) EXPORT_SYMBOL_GPL(synchronize_rcu); static void rcu_barrier_callback(struct rcu_head *notused) @@ -99,19 +90,30 @@ static void rcu_barrier_callback(struct rcu_head *notused) /* * Called with preemption disabled, and from cross-cpu IRQ context. */ -static void rcu_barrier_func(void *notused) +static void rcu_barrier_func(void *type) { int cpu = smp_processor_id(); struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu); atomic_inc(&rcu_barrier_cpu_count); - call_rcu(head, rcu_barrier_callback); + switch ((enum rcu_barrier)type) { + case RCU_BARRIER_STD: + call_rcu(head, rcu_barrier_callback); + break; + case RCU_BARRIER_BH: + call_rcu_bh(head, rcu_barrier_callback); + break; + case RCU_BARRIER_SCHED: + call_rcu_sched(head, rcu_barrier_callback); + break; + } } -/** - * rcu_barrier - Wait until all the in-flight RCUs are complete. +/* + * Orchestrate the specified type of RCU barrier, waiting for all + * RCU callbacks of the specified type to complete. */ -void rcu_barrier(void) +static void _rcu_barrier(enum rcu_barrier type) { BUG_ON(in_interrupt()); /* Take cpucontrol mutex to protect against CPU hotplug */ @@ -127,13 +129,39 @@ void rcu_barrier(void) * until all the callbacks are queued. */ rcu_read_lock(); - on_each_cpu(rcu_barrier_func, NULL, 0, 1); + on_each_cpu(rcu_barrier_func, (void *)type, 1); rcu_read_unlock(); wait_for_completion(&rcu_barrier_completion); mutex_unlock(&rcu_barrier_mutex); } + +/** + * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete. + */ +void rcu_barrier(void) +{ + _rcu_barrier(RCU_BARRIER_STD); +} EXPORT_SYMBOL_GPL(rcu_barrier); +/** + * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete. + */ +void rcu_barrier_bh(void) +{ + _rcu_barrier(RCU_BARRIER_BH); +} +EXPORT_SYMBOL_GPL(rcu_barrier_bh); + +/** + * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks. + */ +void rcu_barrier_sched(void) +{ + _rcu_barrier(RCU_BARRIER_SCHED); +} +EXPORT_SYMBOL_GPL(rcu_barrier_sched); + void __init rcu_init(void) { __rcu_init(); diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index 5e02b774..ca4bbbe 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -46,11 +46,11 @@ #include <asm/atomic.h> #include <linux/bitops.h> #include <linux/module.h> +#include <linux/kthread.h> #include <linux/completion.h> #include <linux/moduleparam.h> #include <linux/percpu.h> #include <linux/notifier.h> -#include <linux/rcupdate.h> #include <linux/cpu.h> #include <linux/random.h> #include <linux/delay.h> @@ -59,14 +59,6 @@ #include <linux/rcupreempt_trace.h> /* - * Macro that prevents the compiler from reordering accesses, but does - * absolutely -nothing- to prevent CPUs from reordering. This is used - * only to mediate communication between mainline code and hardware - * interrupt and NMI handlers. - */ -#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) - -/* * PREEMPT_RCU data structures. */ @@ -82,14 +74,18 @@ struct rcu_data { spinlock_t lock; /* Protect rcu_data fields. */ long completed; /* Number of last completed batch. */ int waitlistcount; - struct tasklet_struct rcu_tasklet; struct rcu_head *nextlist; struct rcu_head **nexttail; struct rcu_head *waitlist[GP_STAGES]; struct rcu_head **waittail[GP_STAGES]; - struct rcu_head *donelist; + struct rcu_head *donelist; /* from waitlist & waitschedlist */ struct rcu_head **donetail; long rcu_flipctr[2]; + struct rcu_head *nextschedlist; + struct rcu_head **nextschedtail; + struct rcu_head *waitschedlist; + struct rcu_head **waitschedtail; + int rcu_sched_sleeping; #ifdef CONFIG_RCU_TRACE struct rcupreempt_trace trace; #endif /* #ifdef CONFIG_RCU_TRACE */ @@ -131,11 +127,24 @@ enum rcu_try_flip_states { rcu_try_flip_waitmb_state, }; +/* + * States for rcu_ctrlblk.rcu_sched_sleep. + */ + +enum rcu_sched_sleep_states { + rcu_sched_not_sleeping, /* Not sleeping, callbacks need GP. */ + rcu_sched_sleep_prep, /* Thinking of sleeping, rechecking. */ + rcu_sched_sleeping, /* Sleeping, awaken if GP needed. */ +}; + struct rcu_ctrlblk { spinlock_t fliplock; /* Protect state-machine transitions. */ long completed; /* Number of last completed batch. */ enum rcu_try_flip_states rcu_try_flip_state; /* The current state of the rcu state machine */ + spinlock_t schedlock; /* Protect rcu_sched sleep state. */ + enum rcu_sched_sleep_states sched_sleep; /* rcu_sched state. */ + wait_queue_head_t sched_wq; /* Place for rcu_sched to sleep. */ }; static DEFINE_PER_CPU(struct rcu_data, rcu_data); @@ -143,8 +152,12 @@ static struct rcu_ctrlblk rcu_ctrlblk = { .fliplock = __SPIN_LOCK_UNLOCKED(rcu_ctrlblk.fliplock), .completed = 0, .rcu_try_flip_state = rcu_try_flip_idle_state, + .schedlock = __SPIN_LOCK_UNLOCKED(rcu_ctrlblk.schedlock), + .sched_sleep = rcu_sched_not_sleeping, + .sched_wq = __WAIT_QUEUE_HEAD_INITIALIZER(rcu_ctrlblk.sched_wq), }; +static struct task_struct *rcu_sched_grace_period_task; #ifdef CONFIG_RCU_TRACE static char *rcu_try_flip_state_names[] = @@ -207,6 +220,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(enum rcu_mb_flag_values, rcu_mb_flag) */ #define RCU_TRACE_RDP(f, rdp) RCU_TRACE(f, &((rdp)->trace)); +#define RCU_SCHED_BATCH_TIME (HZ / 50) + /* * Return the number of RCU batches processed thus far. Useful * for debug and statistics. @@ -411,32 +426,34 @@ static void __rcu_advance_callbacks(struct rcu_data *rdp) } } -#ifdef CONFIG_NO_HZ +DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_dyntick_sched, rcu_dyntick_sched) = { + .dynticks = 1, +}; -DEFINE_PER_CPU(long, dynticks_progress_counter) = 1; -static DEFINE_PER_CPU(long, rcu_dyntick_snapshot); +#ifdef CONFIG_NO_HZ static DEFINE_PER_CPU(int, rcu_update_flag); /** * rcu_irq_enter - Called from Hard irq handlers and NMI/SMI. * * If the CPU was idle with dynamic ticks active, this updates the - * dynticks_progress_counter to let the RCU handling know that the + * rcu_dyntick_sched.dynticks to let the RCU handling know that the * CPU is active. */ void rcu_irq_enter(void) { int cpu = smp_processor_id(); + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); if (per_cpu(rcu_update_flag, cpu)) per_cpu(rcu_update_flag, cpu)++; /* * Only update if we are coming from a stopped ticks mode - * (dynticks_progress_counter is even). + * (rcu_dyntick_sched.dynticks is even). */ if (!in_interrupt() && - (per_cpu(dynticks_progress_counter, cpu) & 0x1) == 0) { + (rdssp->dynticks & 0x1) == 0) { /* * The following might seem like we could have a race * with NMI/SMIs. But this really isn't a problem. @@ -459,12 +476,12 @@ void rcu_irq_enter(void) * RCU read-side critical sections on this CPU would * have already completed. */ - per_cpu(dynticks_progress_counter, cpu)++; + rdssp->dynticks++; /* * The following memory barrier ensures that any * rcu_read_lock() primitives in the irq handler * are seen by other CPUs to follow the above - * increment to dynticks_progress_counter. This is + * increment to rcu_dyntick_sched.dynticks. This is * required in order for other CPUs to correctly * determine when it is safe to advance the RCU * grace-period state machine. @@ -472,7 +489,7 @@ void rcu_irq_enter(void) smp_mb(); /* see above block comment. */ /* * Since we can't determine the dynamic tick mode from - * the dynticks_progress_counter after this routine, + * the rcu_dyntick_sched.dynticks after this routine, * we use a second flag to acknowledge that we came * from an idle state with ticks stopped. */ @@ -480,7 +497,7 @@ void rcu_irq_enter(void) /* * If we take an NMI/SMI now, they will also increment * the rcu_update_flag, and will not update the - * dynticks_progress_counter on exit. That is for + * rcu_dyntick_sched.dynticks on exit. That is for * this IRQ to do. */ } @@ -490,12 +507,13 @@ void rcu_irq_enter(void) * rcu_irq_exit - Called from exiting Hard irq context. * * If the CPU was idle with dynamic ticks active, update the - * dynticks_progress_counter to put let the RCU handling be + * rcu_dyntick_sched.dynticks to put let the RCU handling be * aware that the CPU is going back to idle with no ticks. */ void rcu_irq_exit(void) { int cpu = smp_processor_id(); + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); /* * rcu_update_flag is set if we interrupted the CPU @@ -503,7 +521,7 @@ void rcu_irq_exit(void) * Once this occurs, we keep track of interrupt nesting * because a NMI/SMI could also come in, and we still * only want the IRQ that started the increment of the - * dynticks_progress_counter to be the one that modifies + * rcu_dyntick_sched.dynticks to be the one that modifies * it on exit. */ if (per_cpu(rcu_update_flag, cpu)) { @@ -515,28 +533,29 @@ void rcu_irq_exit(void) /* * If an NMI/SMI happens now we are still - * protected by the dynticks_progress_counter being odd. + * protected by the rcu_dyntick_sched.dynticks being odd. */ /* * The following memory barrier ensures that any * rcu_read_unlock() primitives in the irq handler * are seen by other CPUs to preceed the following - * increment to dynticks_progress_counter. This + * increment to rcu_dyntick_sched.dynticks. This * is required in order for other CPUs to determine * when it is safe to advance the RCU grace-period * state machine. */ smp_mb(); /* see above block comment. */ - per_cpu(dynticks_progress_counter, cpu)++; - WARN_ON(per_cpu(dynticks_progress_counter, cpu) & 0x1); + rdssp->dynticks++; + WARN_ON(rdssp->dynticks & 0x1); } } static void dyntick_save_progress_counter(int cpu) { - per_cpu(rcu_dyntick_snapshot, cpu) = - per_cpu(dynticks_progress_counter, cpu); + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); + + rdssp->dynticks_snap = rdssp->dynticks; } static inline int @@ -544,9 +563,10 @@ rcu_try_flip_waitack_needed(int cpu) { long curr; long snap; + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); - curr = per_cpu(dynticks_progress_counter, cpu); - snap = per_cpu(rcu_dyntick_snapshot, cpu); + curr = rdssp->dynticks; + snap = rdssp->dynticks_snap; smp_mb(); /* force ordering with cpu entering/leaving dynticks. */ /* @@ -567,7 +587,7 @@ rcu_try_flip_waitack_needed(int cpu) * that this CPU already acknowledged the counter. */ - if ((curr - snap) > 2 || (snap & 0x1) == 0) + if ((curr - snap) > 2 || (curr & 0x1) == 0) return 0; /* We need this CPU to explicitly acknowledge the counter flip. */ @@ -580,9 +600,10 @@ rcu_try_flip_waitmb_needed(int cpu) { long curr; long snap; + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); - curr = per_cpu(dynticks_progress_counter, cpu); - snap = per_cpu(rcu_dyntick_snapshot, cpu); + curr = rdssp->dynticks; + snap = rdssp->dynticks_snap; smp_mb(); /* force ordering with cpu entering/leaving dynticks. */ /* @@ -609,14 +630,86 @@ rcu_try_flip_waitmb_needed(int cpu) return 1; } +static void dyntick_save_progress_counter_sched(int cpu) +{ + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); + + rdssp->sched_dynticks_snap = rdssp->dynticks; +} + +static int rcu_qsctr_inc_needed_dyntick(int cpu) +{ + long curr; + long snap; + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); + + curr = rdssp->dynticks; + snap = rdssp->sched_dynticks_snap; + smp_mb(); /* force ordering with cpu entering/leaving dynticks. */ + + /* + * If the CPU remained in dynticks mode for the entire time + * and didn't take any interrupts, NMIs, SMIs, or whatever, + * then it cannot be in the middle of an rcu_read_lock(), so + * the next rcu_read_lock() it executes must use the new value + * of the counter. Therefore, this CPU has been in a quiescent + * state the entire time, and we don't need to wait for it. + */ + + if ((curr == snap) && ((curr & 0x1) == 0)) + return 0; + + /* + * If the CPU passed through or entered a dynticks idle phase with + * no active irq handlers, then, as above, this CPU has already + * passed through a quiescent state. + */ + + if ((curr - snap) > 2 || (snap & 0x1) == 0) + return 0; + + /* We need this CPU to go through a quiescent state. */ + + return 1; +} + #else /* !CONFIG_NO_HZ */ -# define dyntick_save_progress_counter(cpu) do { } while (0) -# define rcu_try_flip_waitack_needed(cpu) (1) -# define rcu_try_flip_waitmb_needed(cpu) (1) +# define dyntick_save_progress_counter(cpu) do { } while (0) +# define rcu_try_flip_waitack_needed(cpu) (1) +# define rcu_try_flip_waitmb_needed(cpu) (1) + +# define dyntick_save_progress_counter_sched(cpu) do { } while (0) +# define rcu_qsctr_inc_needed_dyntick(cpu) (1) #endif /* CONFIG_NO_HZ */ +static void save_qsctr_sched(int cpu) +{ + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); + + rdssp->sched_qs_snap = rdssp->sched_qs; +} + +static inline int rcu_qsctr_inc_needed(int cpu) +{ + struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); + + /* + * If there has been a quiescent state, no more need to wait + * on this CPU. + */ + + if (rdssp->sched_qs != rdssp->sched_qs_snap) { + smp_mb(); /* force ordering with cpu entering schedule(). */ + return 0; + } + + /* We need this CPU to go through a quiescent state. */ + + return 1; +} + /* * Get here when RCU is idle. Decide whether we need to * move out of idle state, and return non-zero if so. @@ -655,7 +748,7 @@ rcu_try_flip_idle(void) /* Now ask each CPU for acknowledgement of the flip. */ - for_each_cpu_mask(cpu, rcu_cpu_online_map) { + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) { per_cpu(rcu_flip_flag, cpu) = rcu_flipped; dyntick_save_progress_counter(cpu); } @@ -673,7 +766,7 @@ rcu_try_flip_waitack(void) int cpu; RCU_TRACE_ME(rcupreempt_trace_try_flip_a1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) if (rcu_try_flip_waitack_needed(cpu) && per_cpu(rcu_flip_flag, cpu) != rcu_flip_seen) { RCU_TRACE_ME(rcupreempt_trace_try_flip_ae1); @@ -705,7 +798,7 @@ rcu_try_flip_waitzero(void) /* Check to see if the sum of the "last" counters is zero. */ RCU_TRACE_ME(rcupreempt_trace_try_flip_z1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) sum += RCU_DATA_CPU(cpu)->rcu_flipctr[lastidx]; if (sum != 0) { RCU_TRACE_ME(rcupreempt_trace_try_flip_ze1); @@ -720,7 +813,7 @@ rcu_try_flip_waitzero(void) smp_mb(); /* ^^^^^^^^^^^^ */ /* Call for a memory barrier from each CPU. */ - for_each_cpu_mask(cpu, rcu_cpu_online_map) { + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) { per_cpu(rcu_mb_flag, cpu) = rcu_mb_needed; dyntick_save_progress_counter(cpu); } @@ -740,7 +833,7 @@ rcu_try_flip_waitmb(void) int cpu; RCU_TRACE_ME(rcupreempt_trace_try_flip_m1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) if (rcu_try_flip_waitmb_needed(cpu) && per_cpu(rcu_mb_flag, cpu) != rcu_mb_done) { RCU_TRACE_ME(rcupreempt_trace_try_flip_me1); @@ -819,6 +912,26 @@ void rcu_check_callbacks(int cpu, int user) unsigned long flags; struct rcu_data *rdp = RCU_DATA_CPU(cpu); + /* + * If this CPU took its interrupt from user mode or from the + * idle loop, and this is not a nested interrupt, then + * this CPU has to have exited all prior preept-disable + * sections of code. So increment the counter to note this. + * + * The memory barrier is needed to handle the case where + * writes from a preempt-disable section of code get reordered + * into schedule() by this CPU's write buffer. So the memory + * barrier makes sure that the rcu_qsctr_inc() is seen by other + * CPUs to happen after any such write. + */ + + if (user || + (idle_cpu(cpu) && !in_softirq() && + hardirq_count() <= (1 << HARDIRQ_SHIFT))) { + smp_mb(); /* Guard against aggressive schedule(). */ + rcu_qsctr_inc(cpu); + } + rcu_check_mb(cpu); if (rcu_ctrlblk.completed == rdp->completed) rcu_try_flip(); @@ -869,6 +982,8 @@ void rcu_offline_cpu(int cpu) struct rcu_head *list = NULL; unsigned long flags; struct rcu_data *rdp = RCU_DATA_CPU(cpu); + struct rcu_head *schedlist = NULL; + struct rcu_head **schedtail = &schedlist; struct rcu_head **tail = &list; /* @@ -882,6 +997,11 @@ void rcu_offline_cpu(int cpu) rcu_offline_cpu_enqueue(rdp->waitlist[i], rdp->waittail[i], list, tail); rcu_offline_cpu_enqueue(rdp->nextlist, rdp->nexttail, list, tail); + rcu_offline_cpu_enqueue(rdp->waitschedlist, rdp->waitschedtail, + schedlist, schedtail); + rcu_offline_cpu_enqueue(rdp->nextschedlist, rdp->nextschedtail, + schedlist, schedtail); + rdp->rcu_sched_sleeping = 0; spin_unlock_irqrestore(&rdp->lock, flags); rdp->waitlistcount = 0; @@ -916,36 +1036,50 @@ void rcu_offline_cpu(int cpu) * fix. */ - local_irq_save(flags); + local_irq_save(flags); /* disable preempt till we know what lock. */ rdp = RCU_DATA_ME(); spin_lock(&rdp->lock); *rdp->nexttail = list; if (list) rdp->nexttail = tail; + *rdp->nextschedtail = schedlist; + if (schedlist) + rdp->nextschedtail = schedtail; spin_unlock_irqrestore(&rdp->lock, flags); } -void __devinit rcu_online_cpu(int cpu) +#else /* #ifdef CONFIG_HOTPLUG_CPU */ + +void rcu_offline_cpu(int cpu) +{ +} + +#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ + +void __cpuinit rcu_online_cpu(int cpu) { unsigned long flags; + struct rcu_data *rdp; spin_lock_irqsave(&rcu_ctrlblk.fliplock, flags); cpu_set(cpu, rcu_cpu_online_map); spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags); -} -#else /* #ifdef CONFIG_HOTPLUG_CPU */ - -void rcu_offline_cpu(int cpu) -{ -} + /* + * The rcu_sched grace-period processing might have bypassed + * this CPU, given that it was not in the rcu_cpu_online_map + * when the grace-period scan started. This means that the + * grace-period task might sleep. So make sure that if this + * should happen, the first callback posted to this CPU will + * wake up the grace-period task if need be. + */ -void __devinit rcu_online_cpu(int cpu) -{ + rdp = RCU_DATA_CPU(cpu); + spin_lock_irqsave(&rdp->lock, flags); + rdp->rcu_sched_sleeping = 1; + spin_unlock_irqrestore(&rdp->lock, flags); } -#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ - static void rcu_process_callbacks(struct softirq_action *unused) { unsigned long flags; @@ -986,31 +1120,196 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) *rdp->nexttail = head; rdp->nexttail = &head->next; RCU_TRACE_RDP(rcupreempt_trace_next_add, rdp); - spin_unlock(&rdp->lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&rdp->lock, flags); } EXPORT_SYMBOL_GPL(call_rcu); +void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) +{ + unsigned long flags; + struct rcu_data *rdp; + int wake_gp = 0; + + head->func = func; + head->next = NULL; + local_irq_save(flags); + rdp = RCU_DATA_ME(); + spin_lock(&rdp->lock); + *rdp->nextschedtail = head; + rdp->nextschedtail = &head->next; + if (rdp->rcu_sched_sleeping) { + + /* Grace-period processing might be sleeping... */ + + rdp->rcu_sched_sleeping = 0; + wake_gp = 1; + } + spin_unlock_irqrestore(&rdp->lock, flags); + if (wake_gp) { + + /* Wake up grace-period processing, unless someone beat us. */ + + spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags); + if (rcu_ctrlblk.sched_sleep != rcu_sched_sleeping) + wake_gp = 0; + rcu_ctrlblk.sched_sleep = rcu_sched_not_sleeping; + spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags); + if (wake_gp) + wake_up_interruptible(&rcu_ctrlblk.sched_wq); + } +} +EXPORT_SYMBOL_GPL(call_rcu_sched); + /* * Wait until all currently running preempt_disable() code segments * (including hardware-irq-disable segments) complete. Note that * in -rt this does -not- necessarily result in all currently executing * interrupt -handlers- having completed. */ -void __synchronize_sched(void) +synchronize_rcu_xxx(__synchronize_sched, call_rcu_sched) +EXPORT_SYMBOL_GPL(__synchronize_sched); + +/* + * kthread function that manages call_rcu_sched grace periods. + */ +static int rcu_sched_grace_period(void *arg) { - cpumask_t oldmask; + int couldsleep; /* might sleep after current pass. */ + int couldsleepnext = 0; /* might sleep after next pass. */ int cpu; + unsigned long flags; + struct rcu_data *rdp; + int ret; - if (sched_getaffinity(0, &oldmask) < 0) - oldmask = cpu_possible_map; - for_each_online_cpu(cpu) { - sched_setaffinity(0, &cpumask_of_cpu(cpu)); - schedule(); - } - sched_setaffinity(0, &oldmask); + /* + * Each pass through the following loop handles one + * rcu_sched grace period cycle. + */ + do { + /* Save each CPU's current state. */ + + for_each_online_cpu(cpu) { + dyntick_save_progress_counter_sched(cpu); + save_qsctr_sched(cpu); + } + + /* + * Sleep for about an RCU grace-period's worth to + * allow better batching and to consume less CPU. + */ + schedule_timeout_interruptible(RCU_SCHED_BATCH_TIME); + + /* + * If there was nothing to do last time, prepare to + * sleep at the end of the current grace period cycle. + */ + couldsleep = couldsleepnext; + couldsleepnext = 1; + if (couldsleep) { + spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags); + rcu_ctrlblk.sched_sleep = rcu_sched_sleep_prep; + spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags); + } + + /* + * Wait on each CPU in turn to have either visited + * a quiescent state or been in dynticks-idle mode. + */ + for_each_online_cpu(cpu) { + while (rcu_qsctr_inc_needed(cpu) && + rcu_qsctr_inc_needed_dyntick(cpu)) { + /* resched_cpu(cpu); @@@ */ + schedule_timeout_interruptible(1); + } + } + + /* Advance callbacks for each CPU. */ + + for_each_online_cpu(cpu) { + + rdp = RCU_DATA_CPU(cpu); + spin_lock_irqsave(&rdp->lock, flags); + + /* + * We are running on this CPU irq-disabled, so no + * CPU can go offline until we re-enable irqs. + * The current CPU might have already gone + * offline (between the for_each_offline_cpu and + * the spin_lock_irqsave), but in that case all its + * callback lists will be empty, so no harm done. + * + * Advance the callbacks! We share normal RCU's + * donelist, since callbacks are invoked the + * same way in either case. + */ + if (rdp->waitschedlist != NULL) { + *rdp->donetail = rdp->waitschedlist; + rdp->donetail = rdp->waitschedtail; + + /* + * Next rcu_check_callbacks() will + * do the required raise_softirq(). + */ + } + if (rdp->nextschedlist != NULL) { + rdp->waitschedlist = rdp->nextschedlist; + rdp->waitschedtail = rdp->nextschedtail; + couldsleep = 0; + couldsleepnext = 0; + } else { + rdp->waitschedlist = NULL; + rdp->waitschedtail = &rdp->waitschedlist; + } + rdp->nextschedlist = NULL; + rdp->nextschedtail = &rdp->nextschedlist; + + /* Mark sleep intention. */ + + rdp->rcu_sched_sleeping = couldsleep; + + spin_unlock_irqrestore(&rdp->lock, flags); + } + + /* If we saw callbacks on the last scan, go deal with them. */ + + if (!couldsleep) + continue; + + /* Attempt to block... */ + + spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags); + if (rcu_ctrlblk.sched_sleep != rcu_sched_sleep_prep) { + + /* + * Someone posted a callback after we scanned. + * Go take care of it. + */ + spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags); + couldsleepnext = 0; + continue; + } + + /* Block until the next person posts a callback. */ + + rcu_ctrlblk.sched_sleep = rcu_sched_sleeping; + spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags); + ret = 0; + __wait_event_interruptible(rcu_ctrlblk.sched_wq, + rcu_ctrlblk.sched_sleep != rcu_sched_sleeping, + ret); + + /* + * Signals would prevent us from sleeping, and we cannot + * do much with them in any case. So flush them. + */ + if (ret) + flush_signals(current); + couldsleepnext = 0; + + } while (!kthread_should_stop()); + + return (0); } -EXPORT_SYMBOL_GPL(__synchronize_sched); /* * Check to see if any future RCU-related work will need to be done @@ -1027,7 +1326,9 @@ int rcu_needs_cpu(int cpu) return (rdp->donelist != NULL || !!rdp->waitlistcount || - rdp->nextlist != NULL); + rdp->nextlist != NULL || + rdp->nextschedlist != NULL || + rdp->waitschedlist != NULL); } int rcu_pending(int cpu) @@ -1038,7 +1339,9 @@ int rcu_pending(int cpu) if (rdp->donelist != NULL || !!rdp->waitlistcount || - rdp->nextlist != NULL) + rdp->nextlist != NULL || + rdp->nextschedlist != NULL || + rdp->waitschedlist != NULL) return 1; /* The RCU core needs an acknowledgement from this CPU. */ @@ -1105,6 +1408,11 @@ void __init __rcu_init(void) rdp->donetail = &rdp->donelist; rdp->rcu_flipctr[0] = 0; rdp->rcu_flipctr[1] = 0; + rdp->nextschedlist = NULL; + rdp->nextschedtail = &rdp->nextschedlist; + rdp->waitschedlist = NULL; + rdp->waitschedtail = &rdp->waitschedlist; + rdp->rcu_sched_sleeping = 0; } register_cpu_notifier(&rcu_nb); @@ -1123,15 +1431,19 @@ void __init __rcu_init(void) for_each_online_cpu(cpu) rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long) cpu); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); + open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } /* - * Deprecated, use synchronize_rcu() or synchronize_sched() instead. + * Late-boot-time RCU initialization that must wait until after scheduler + * has been initialized. */ -void synchronize_kernel(void) +void __init rcu_init_sched(void) { - synchronize_rcu(); + rcu_sched_grace_period_task = kthread_run(rcu_sched_grace_period, + NULL, + "rcu_sched_grace_period"); + WARN_ON(IS_ERR(rcu_sched_grace_period_task)); } #ifdef CONFIG_RCU_TRACE diff --git a/kernel/rcupreempt_trace.c b/kernel/rcupreempt_trace.c index 49ac4947..35c2d33 100644 --- a/kernel/rcupreempt_trace.c +++ b/kernel/rcupreempt_trace.c @@ -38,7 +38,6 @@ #include <linux/moduleparam.h> #include <linux/percpu.h> #include <linux/notifier.h> -#include <linux/rcupdate.h> #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/rcupreempt_trace.h> @@ -309,11 +308,16 @@ out: static int __init rcupreempt_trace_init(void) { + int ret; + mutex_init(&rcupreempt_trace_mutex); rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); if (!rcupreempt_trace_buf) return 1; - return rcupreempt_debugfs_init(); + ret = rcupreempt_debugfs_init(); + if (ret) + kfree(rcupreempt_trace_buf); + return ret; } static void __exit rcupreempt_trace_cleanup(void) diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 33acc424..90b5b12 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -57,7 +57,9 @@ static int stat_interval; /* Interval between stats, in seconds. */ /* Defaults to "only at end of test". */ static int verbose; /* Print more debug info. */ static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ -static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/ +static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/ +static int stutter = 5; /* Start/stop testing interval (in sec) */ +static int irqreader = 1; /* RCU readers from irq (timers). */ static char *torture_type = "rcu"; /* What RCU implementation to torture. */ module_param(nreaders, int, 0444); @@ -72,6 +74,10 @@ module_param(test_no_idle_hz, bool, 0444); MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); module_param(shuffle_interval, int, 0444); MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); +module_param(stutter, int, 0444); +MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); +module_param(irqreader, int, 0444); +MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); module_param(torture_type, charp, 0444); MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); @@ -91,6 +97,7 @@ static struct task_struct **fakewriter_tasks; static struct task_struct **reader_tasks; static struct task_struct *stats_task; static struct task_struct *shuffler_task; +static struct task_struct *stutter_task; #define RCU_TORTURE_PIPE_LEN 10 @@ -117,8 +124,18 @@ static atomic_t n_rcu_torture_alloc_fail; static atomic_t n_rcu_torture_free; static atomic_t n_rcu_torture_mberror; static atomic_t n_rcu_torture_error; +static long n_rcu_torture_timers = 0; static struct list_head rcu_torture_removed; +static int stutter_pause_test = 0; + +#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) +#define RCUTORTURE_RUNNABLE_INIT 1 +#else +#define RCUTORTURE_RUNNABLE_INIT 0 +#endif +int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; + /* * Allocate an element from the rcu_tortures pool. */ @@ -179,6 +196,16 @@ rcu_random(struct rcu_random_state *rrsp) return swahw32(rrsp->rrs_state); } +static void +rcu_stutter_wait(void) +{ + while (stutter_pause_test || !rcutorture_runnable) + if (rcutorture_runnable) + schedule_timeout_interruptible(1); + else + schedule_timeout_interruptible(round_jiffies_relative(HZ)); +} + /* * Operations vector for selecting different types of tests. */ @@ -192,7 +219,9 @@ struct rcu_torture_ops { int (*completed)(void); void (*deferredfree)(struct rcu_torture *p); void (*sync)(void); + void (*cb_barrier)(void); int (*stats)(char *page); + int irqcapable; char *name; }; static struct rcu_torture_ops *cur_ops = NULL; @@ -265,7 +294,9 @@ static struct rcu_torture_ops rcu_ops = { .completed = rcu_torture_completed, .deferredfree = rcu_torture_deferred_free, .sync = synchronize_rcu, + .cb_barrier = rcu_barrier, .stats = NULL, + .irqcapable = 1, .name = "rcu" }; @@ -304,7 +335,9 @@ static struct rcu_torture_ops rcu_sync_ops = { .completed = rcu_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = synchronize_rcu, + .cb_barrier = NULL, .stats = NULL, + .irqcapable = 1, .name = "rcu_sync" }; @@ -364,7 +397,9 @@ static struct rcu_torture_ops rcu_bh_ops = { .completed = rcu_bh_torture_completed, .deferredfree = rcu_bh_torture_deferred_free, .sync = rcu_bh_torture_synchronize, + .cb_barrier = rcu_barrier_bh, .stats = NULL, + .irqcapable = 1, .name = "rcu_bh" }; @@ -377,7 +412,9 @@ static struct rcu_torture_ops rcu_bh_sync_ops = { .completed = rcu_bh_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = rcu_bh_torture_synchronize, + .cb_barrier = NULL, .stats = NULL, + .irqcapable = 1, .name = "rcu_bh_sync" }; @@ -458,6 +495,7 @@ static struct rcu_torture_ops srcu_ops = { .completed = srcu_torture_completed, .deferredfree = rcu_sync_torture_deferred_free, .sync = srcu_torture_synchronize, + .cb_barrier = NULL, .stats = srcu_torture_stats, .name = "srcu" }; @@ -482,6 +520,11 @@ static int sched_torture_completed(void) return 0; } +static void rcu_sched_torture_deferred_free(struct rcu_torture *p) +{ + call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); +} + static void sched_torture_synchronize(void) { synchronize_sched(); @@ -494,12 +537,28 @@ static struct rcu_torture_ops sched_ops = { .readdelay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = sched_torture_read_unlock, .completed = sched_torture_completed, - .deferredfree = rcu_sync_torture_deferred_free, + .deferredfree = rcu_sched_torture_deferred_free, .sync = sched_torture_synchronize, + .cb_barrier = rcu_barrier_sched, .stats = NULL, + .irqcapable = 1, .name = "sched" }; +static struct rcu_torture_ops sched_ops_sync = { + .init = rcu_sync_torture_init, + .cleanup = NULL, + .readlock = sched_torture_read_lock, + .readdelay = rcu_read_delay, /* just reuse rcu's version. */ + .readunlock = sched_torture_read_unlock, + .completed = sched_torture_completed, + .deferredfree = rcu_sync_torture_deferred_free, + .sync = sched_torture_synchronize, + .cb_barrier = NULL, + .stats = NULL, + .name = "sched_sync" +}; + /* * RCU torture writer kthread. Repeatedly substitutes a new structure * for that pointed to by rcu_torture_current, freeing the old structure @@ -537,6 +596,7 @@ rcu_torture_writer(void *arg) } rcu_torture_current_version++; oldbatch = cur_ops->completed(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); while (!kthread_should_stop()) @@ -560,6 +620,7 @@ rcu_torture_fakewriter(void *arg) schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); udelay(rcu_random(&rand) & 0x3ff); cur_ops->sync(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); @@ -569,6 +630,52 @@ rcu_torture_fakewriter(void *arg) } /* + * RCU torture reader from timer handler. Dereferences rcu_torture_current, + * incrementing the corresponding element of the pipeline array. The + * counter in the element should never be greater than 1, otherwise, the + * RCU implementation is broken. + */ +static void rcu_torture_timer(unsigned long unused) +{ + int idx; + int completed; + static DEFINE_RCU_RANDOM(rand); + static DEFINE_SPINLOCK(rand_lock); + struct rcu_torture *p; + int pipe_count; + + idx = cur_ops->readlock(); + completed = cur_ops->completed(); + p = rcu_dereference(rcu_torture_current); + if (p == NULL) { + /* Leave because rcu_torture_writer is not yet underway */ + cur_ops->readunlock(idx); + return; + } + if (p->rtort_mbtest == 0) + atomic_inc(&n_rcu_torture_mberror); + spin_lock(&rand_lock); + cur_ops->readdelay(&rand); + n_rcu_torture_timers++; + spin_unlock(&rand_lock); + preempt_disable(); + pipe_count = p->rtort_pipe_count; + if (pipe_count > RCU_TORTURE_PIPE_LEN) { + /* Should not happen, but... */ + pipe_count = RCU_TORTURE_PIPE_LEN; + } + ++__get_cpu_var(rcu_torture_count)[pipe_count]; + completed = cur_ops->completed() - completed; + if (completed > RCU_TORTURE_PIPE_LEN) { + /* Should not happen, but... */ + completed = RCU_TORTURE_PIPE_LEN; + } + ++__get_cpu_var(rcu_torture_batch)[completed]; + preempt_enable(); + cur_ops->readunlock(idx); +} + +/* * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, * incrementing the corresponding element of the pipeline array. The * counter in the element should never be greater than 1, otherwise, the @@ -582,11 +689,18 @@ rcu_torture_reader(void *arg) DEFINE_RCU_RANDOM(rand); struct rcu_torture *p; int pipe_count; + struct timer_list t; VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); set_user_nice(current, 19); + if (irqreader && cur_ops->irqcapable) + setup_timer_on_stack(&t, rcu_torture_timer, 0); do { + if (irqreader && cur_ops->irqcapable) { + if (!timer_pending(&t)) + mod_timer(&t, 1); + } idx = cur_ops->readlock(); completed = cur_ops->completed(); p = rcu_dereference(rcu_torture_current); @@ -615,8 +729,11 @@ rcu_torture_reader(void *arg) preempt_enable(); cur_ops->readunlock(idx); schedule(); + rcu_stutter_wait(); } while (!kthread_should_stop() && !fullstop); VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); + if (irqreader && cur_ops->irqcapable) + del_timer_sync(&t); while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; @@ -647,20 +764,22 @@ rcu_torture_printk(char *page) cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); cnt += sprintf(&page[cnt], "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " - "rtmbe: %d", + "rtmbe: %d nt: %ld", rcu_torture_current, rcu_torture_current_version, list_empty(&rcu_torture_freelist), atomic_read(&n_rcu_torture_alloc), atomic_read(&n_rcu_torture_alloc_fail), atomic_read(&n_rcu_torture_free), - atomic_read(&n_rcu_torture_mberror)); + atomic_read(&n_rcu_torture_mberror), + n_rcu_torture_timers); if (atomic_read(&n_rcu_torture_mberror) != 0) cnt += sprintf(&page[cnt], " !!!"); cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); if (i > 1) { cnt += sprintf(&page[cnt], "!!! "); atomic_inc(&n_rcu_torture_error); + WARN_ON_ONCE(1); } cnt += sprintf(&page[cnt], "Reader Pipe: "); for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) @@ -785,15 +904,34 @@ rcu_torture_shuffle(void *arg) return 0; } +/* Cause the rcutorture test to "stutter", starting and stopping all + * threads periodically. + */ +static int +rcu_torture_stutter(void *arg) +{ + VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); + do { + schedule_timeout_interruptible(stutter * HZ); + stutter_pause_test = 1; + if (!kthread_should_stop()) + schedule_timeout_interruptible(stutter * HZ); + stutter_pause_test = 0; + } while (!kthread_should_stop()); + VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); + return 0; +} + static inline void rcu_torture_print_module_parms(char *tag) { printk(KERN_ALERT "%s" TORTURE_FLAG "--- %s: nreaders=%d nfakewriters=%d " "stat_interval=%d verbose=%d test_no_idle_hz=%d " - "shuffle_interval = %d\n", + "shuffle_interval=%d stutter=%d irqreader=%d\n", torture_type, tag, nrealreaders, nfakewriters, - stat_interval, verbose, test_no_idle_hz, shuffle_interval); + stat_interval, verbose, test_no_idle_hz, shuffle_interval, + stutter, irqreader); } static void @@ -802,6 +940,11 @@ rcu_torture_cleanup(void) int i; fullstop = 1; + if (stutter_task) { + VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); + kthread_stop(stutter_task); + } + stutter_task = NULL; if (shuffler_task) { VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); kthread_stop(shuffler_task); @@ -848,7 +991,9 @@ rcu_torture_cleanup(void) stats_task = NULL; /* Wait for all RCU callbacks to fire. */ - rcu_barrier(); + + if (cur_ops->cb_barrier != NULL) + cur_ops->cb_barrier(); rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ @@ -868,7 +1013,7 @@ rcu_torture_init(void) int firsterr = 0; static struct rcu_torture_ops *torture_ops[] = { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops, - &srcu_ops, &sched_ops, }; + &srcu_ops, &sched_ops, &sched_ops_sync, }; /* Process args and tell the world that the torturer is on the job. */ for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { @@ -988,6 +1133,19 @@ rcu_torture_init(void) goto unwind; } } + if (stutter < 0) + stutter = 0; + if (stutter) { + /* Create the stutter thread */ + stutter_task = kthread_run(rcu_torture_stutter, NULL, + "rcu_torture_stutter"); + if (IS_ERR(stutter_task)) { + firsterr = PTR_ERR(stutter_task); + VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); + stutter_task = NULL; + goto unwind; + } + } return 0; unwind: diff --git a/kernel/relay.c b/kernel/relay.c index 7de644c..8d13a78 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -407,6 +407,35 @@ void relay_reset(struct rchan *chan) } EXPORT_SYMBOL_GPL(relay_reset); +static inline void relay_set_buf_dentry(struct rchan_buf *buf, + struct dentry *dentry) +{ + buf->dentry = dentry; + buf->dentry->d_inode->i_size = buf->early_bytes; +} + +static struct dentry *relay_create_buf_file(struct rchan *chan, + struct rchan_buf *buf, + unsigned int cpu) +{ + struct dentry *dentry; + char *tmpname; + + tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); + if (!tmpname) + return NULL; + snprintf(tmpname, NAME_MAX, "%s%d", chan->base_filename, cpu); + + /* Create file in fs */ + dentry = chan->cb->create_buf_file(tmpname, chan->parent, + S_IRUSR, buf, + &chan->is_global); + + kfree(tmpname); + + return dentry; +} + /* * relay_open_buf - create a new relay channel buffer * @@ -416,45 +445,34 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) { struct rchan_buf *buf = NULL; struct dentry *dentry; - char *tmpname; if (chan->is_global) return chan->buf[0]; - tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); - if (!tmpname) - goto end; - snprintf(tmpname, NAME_MAX, "%s%d", chan->base_filename, cpu); - buf = relay_create_buf(chan); if (!buf) - goto free_name; + return NULL; + + if (chan->has_base_filename) { + dentry = relay_create_buf_file(chan, buf, cpu); + if (!dentry) + goto free_buf; + relay_set_buf_dentry(buf, dentry); + } buf->cpu = cpu; __relay_reset(buf, 1); - /* Create file in fs */ - dentry = chan->cb->create_buf_file(tmpname, chan->parent, S_IRUSR, - buf, &chan->is_global); - if (!dentry) - goto free_buf; - - buf->dentry = dentry; - if(chan->is_global) { chan->buf[0] = buf; buf->cpu = 0; } - goto free_name; + return buf; free_buf: relay_destroy_buf(buf); - buf = NULL; -free_name: - kfree(tmpname); -end: - return buf; + return NULL; } /** @@ -537,8 +555,8 @@ static int __cpuinit relay_hotcpu_callback(struct notifier_block *nb, /** * relay_open - create a new relay channel - * @base_filename: base name of files to create - * @parent: dentry of parent directory, %NULL for root directory + * @base_filename: base name of files to create, %NULL for buffering only + * @parent: dentry of parent directory, %NULL for root directory or buffer * @subbuf_size: size of sub-buffers * @n_subbufs: number of sub-buffers * @cb: client callback functions @@ -560,8 +578,6 @@ struct rchan *relay_open(const char *base_filename, { unsigned int i; struct rchan *chan; - if (!base_filename) - return NULL; if (!(subbuf_size && n_subbufs)) return NULL; @@ -576,7 +592,10 @@ struct rchan *relay_open(const char *base_filename, chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs); chan->parent = parent; chan->private_data = private_data; - strlcpy(chan->base_filename, base_filename, NAME_MAX); + if (base_filename) { + chan->has_base_filename = 1; + strlcpy(chan->base_filename, base_filename, NAME_MAX); + } setup_callbacks(chan, cb); kref_init(&chan->kref); @@ -604,6 +623,94 @@ free_bufs: } EXPORT_SYMBOL_GPL(relay_open); +struct rchan_percpu_buf_dispatcher { + struct rchan_buf *buf; + struct dentry *dentry; +}; + +/* Called in atomic context. */ +static void __relay_set_buf_dentry(void *info) +{ + struct rchan_percpu_buf_dispatcher *p = info; + + relay_set_buf_dentry(p->buf, p->dentry); +} + +/** + * relay_late_setup_files - triggers file creation + * @chan: channel to operate on + * @base_filename: base name of files to create + * @parent: dentry of parent directory, %NULL for root directory + * + * Returns 0 if successful, non-zero otherwise. + * + * Use to setup files for a previously buffer-only channel. + * Useful to do early tracing in kernel, before VFS is up, for example. + */ +int relay_late_setup_files(struct rchan *chan, + const char *base_filename, + struct dentry *parent) +{ + int err = 0; + unsigned int i, curr_cpu; + unsigned long flags; + struct dentry *dentry; + struct rchan_percpu_buf_dispatcher disp; + + if (!chan || !base_filename) + return -EINVAL; + + strlcpy(chan->base_filename, base_filename, NAME_MAX); + + mutex_lock(&relay_channels_mutex); + /* Is chan already set up? */ + if (unlikely(chan->has_base_filename)) + return -EEXIST; + chan->has_base_filename = 1; + chan->parent = parent; + curr_cpu = get_cpu(); + /* + * The CPU hotplug notifier ran before us and created buffers with + * no files associated. So it's safe to call relay_setup_buf_file() + * on all currently online CPUs. + */ + for_each_online_cpu(i) { + if (unlikely(!chan->buf[i])) { + printk(KERN_ERR "relay_late_setup_files: CPU %u " + "has no buffer, it must have!\n", i); + BUG(); + err = -EINVAL; + break; + } + + dentry = relay_create_buf_file(chan, chan->buf[i], i); + if (unlikely(!dentry)) { + err = -EINVAL; + break; + } + + if (curr_cpu == i) { + local_irq_save(flags); + relay_set_buf_dentry(chan->buf[i], dentry); + local_irq_restore(flags); + } else { + disp.buf = chan->buf[i]; + disp.dentry = dentry; + smp_mb(); + /* relay_channels_mutex must be held, so wait. */ + err = smp_call_function_single(i, + __relay_set_buf_dentry, + &disp, 1); + } + if (unlikely(err)) + break; + } + put_cpu(); + mutex_unlock(&relay_channels_mutex); + + return err; +} + /** * relay_switch_subbuf - switch to a new sub-buffer * @buf: channel buffer @@ -627,8 +734,13 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; buf->padding[old_subbuf] = buf->prev_padding; buf->subbufs_produced++; - buf->dentry->d_inode->i_size += buf->chan->subbuf_size - - buf->padding[old_subbuf]; + if (buf->dentry) + buf->dentry->d_inode->i_size += + buf->chan->subbuf_size - + buf->padding[old_subbuf]; + else + buf->early_bytes += buf->chan->subbuf_size - + buf->padding[old_subbuf]; smp_mb(); if (waitqueue_active(&buf->read_wait)) /* @@ -832,6 +944,10 @@ static void relay_file_read_consume(struct rchan_buf *buf, size_t n_subbufs = buf->chan->n_subbufs; size_t read_subbuf; + if (buf->subbufs_produced == buf->subbufs_consumed && + buf->offset == buf->bytes_consumed) + return; + if (buf->bytes_consumed + bytes_consumed > subbuf_size) { relay_subbufs_consumed(buf->chan, buf->cpu, 1); buf->bytes_consumed = 0; @@ -863,6 +979,8 @@ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) relay_file_read_consume(buf, read_pos, 0); + consumed = buf->subbufs_consumed; + if (unlikely(buf->offset > subbuf_size)) { if (produced == consumed) return 0; @@ -881,8 +999,12 @@ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) if (consumed > produced) produced += n_subbufs * subbuf_size; - if (consumed == produced) + if (consumed == produced) { + if (buf->offset == subbuf_size && + buf->subbufs_produced > buf->subbufs_consumed) + return 1; return 0; + } return 1; } @@ -1237,4 +1359,4 @@ static __init int relay_init(void) return 0; } -module_init(relay_init); +early_initcall(relay_init); diff --git a/kernel/res_counter.c b/kernel/res_counter.c index d3c61b4..f275c8e 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -13,6 +13,7 @@ #include <linux/slab.h> #include <linux/res_counter.h> #include <linux/uaccess.h> +#include <linux/mm.h> void res_counter_init(struct res_counter *counter) { @@ -102,44 +103,37 @@ u64 res_counter_read_u64(struct res_counter *counter, int member) return *res_counter_member(counter, member); } -ssize_t res_counter_write(struct res_counter *counter, int member, - const char __user *userbuf, size_t nbytes, loff_t *pos, - int (*write_strategy)(char *st_buf, unsigned long long *val)) +int res_counter_memparse_write_strategy(const char *buf, + unsigned long long *res) { - int ret; - char *buf, *end; - unsigned long flags; - unsigned long long tmp, *val; - - buf = kmalloc(nbytes + 1, GFP_KERNEL); - ret = -ENOMEM; - if (buf == NULL) - goto out; + char *end; + /* FIXME - make memparse() take const char* args */ + *res = memparse((char *)buf, &end); + if (*end != '\0') + return -EINVAL; - buf[nbytes] = '\0'; - ret = -EFAULT; - if (copy_from_user(buf, userbuf, nbytes)) - goto out_free; + *res = PAGE_ALIGN(*res); + return 0; +} - ret = -EINVAL; +int res_counter_write(struct res_counter *counter, int member, + const char *buf, write_strategy_fn write_strategy) +{ + char *end; + unsigned long flags; + unsigned long long tmp, *val; - strstrip(buf); if (write_strategy) { - if (write_strategy(buf, &tmp)) { - goto out_free; - } + if (write_strategy(buf, &tmp)) + return -EINVAL; } else { tmp = simple_strtoull(buf, &end, 10); if (*end != '\0') - goto out_free; + return -EINVAL; } spin_lock_irqsave(&counter->lock, flags); val = res_counter_member(counter, member); *val = tmp; spin_unlock_irqrestore(&counter->lock, flags); - ret = nbytes; -out_free: - kfree(buf); -out: - return ret; + return 0; } diff --git a/kernel/resource.c b/kernel/resource.c index 74af2d7..414d6fc 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -362,35 +362,21 @@ int allocate_resource(struct resource *root, struct resource *new, EXPORT_SYMBOL(allocate_resource); -/** - * insert_resource - Inserts a resource in the resource tree - * @parent: parent of the new resource - * @new: new resource to insert - * - * Returns 0 on success, -EBUSY if the resource can't be inserted. - * - * This function is equivalent to request_resource when no conflict - * happens. If a conflict happens, and the conflicting resources - * entirely fit within the range of the new resource, then the new - * resource is inserted and the conflicting resources become children of - * the new resource. +/* + * Insert a resource into the resource tree. If successful, return NULL, + * otherwise return the conflicting resource (compare to __request_resource()) */ -int insert_resource(struct resource *parent, struct resource *new) +static struct resource * __insert_resource(struct resource *parent, struct resource *new) { - int result; struct resource *first, *next; - write_lock(&resource_lock); - for (;; parent = first) { - result = 0; first = __request_resource(parent, new); if (!first) - goto out; + return first; - result = -EBUSY; if (first == parent) - goto out; + return first; if ((first->start > new->start) || (first->end < new->end)) break; @@ -401,15 +387,13 @@ int insert_resource(struct resource *parent, struct resource *new) for (next = first; ; next = next->sibling) { /* Partial overlap? Bad, and unfixable */ if (next->start < new->start || next->end > new->end) - goto out; + return next; if (!next->sibling) break; if (next->sibling->start > new->end) break; } - result = 0; - new->parent = parent; new->sibling = next->sibling; new->child = first; @@ -426,10 +410,64 @@ int insert_resource(struct resource *parent, struct resource *new) next = next->sibling; next->sibling = new; } + return NULL; +} - out: +/** + * insert_resource - Inserts a resource in the resource tree + * @parent: parent of the new resource + * @new: new resource to insert + * + * Returns 0 on success, -EBUSY if the resource can't be inserted. + * + * This function is equivalent to request_resource when no conflict + * happens. If a conflict happens, and the conflicting resources + * entirely fit within the range of the new resource, then the new + * resource is inserted and the conflicting resources become children of + * the new resource. + */ +int insert_resource(struct resource *parent, struct resource *new) +{ + struct resource *conflict; + + write_lock(&resource_lock); + conflict = __insert_resource(parent, new); + write_unlock(&resource_lock); + return conflict ? -EBUSY : 0; +} + +/** + * insert_resource_expand_to_fit - Insert a resource into the resource tree + * @root: root resource descriptor + * @new: new resource to insert + * + * Insert a resource into the resource tree, possibly expanding it in order + * to make it encompass any conflicting resources. + */ +void insert_resource_expand_to_fit(struct resource *root, struct resource *new) +{ + if (new->parent) + return; + + write_lock(&resource_lock); + for (;;) { + struct resource *conflict; + + conflict = __insert_resource(root, new); + if (!conflict) + break; + if (conflict == root) + break; + + /* Ok, expand resource to cover the conflict, then try again .. */ + if (conflict->start < new->start) + new->start = conflict->start; + if (conflict->end > new->end) + new->end = conflict->end; + + printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); + } write_unlock(&resource_lock); - return result; } /** @@ -478,6 +516,74 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t return result; } +static void __init __reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + struct resource *parent = root; + struct resource *conflict; + struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + + if (!res) + return; + + res->name = name; + res->start = start; + res->end = end; + res->flags = IORESOURCE_BUSY; + + for (;;) { + conflict = __request_resource(parent, res); + if (!conflict) + break; + if (conflict != parent) { + parent = conflict; + if (!(conflict->flags & IORESOURCE_BUSY)) + continue; + } + + /* Uhhuh, that didn't work out.. */ + kfree(res); + res = NULL; + break; + } + + if (!res) { + printk(KERN_DEBUG " __reserve_region_with_split: (%s) [%llx, %llx], res: (%s) [%llx, %llx]\n", + conflict->name, conflict->start, conflict->end, + name, start, end); + + /* failed, split and try again */ + + /* conflict coverred whole area */ + if (conflict->start <= start && conflict->end >= end) + return; + + if (conflict->start > start) + __reserve_region_with_split(root, start, conflict->start-1, name); + if (!(conflict->flags & IORESOURCE_BUSY)) { + resource_size_t common_start, common_end; + + common_start = max(conflict->start, start); + common_end = min(conflict->end, end); + if (common_start < common_end) + __reserve_region_with_split(root, common_start, common_end, name); + } + if (conflict->end < end) + __reserve_region_with_split(root, conflict->end+1, end, name); + } + +} + +void reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + write_lock(&resource_lock); + __reserve_region_with_split(root, start, end, name); + write_unlock(&resource_lock); +} + EXPORT_SYMBOL(adjust_resource); /** @@ -490,7 +596,7 @@ resource_size_t resource_alignment(struct resource *res) { switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { case IORESOURCE_SIZEALIGN: - return res->end - res->start + 1; + return resource_size(res); case IORESOURCE_STARTALIGN: return res->start; default: diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c index 092e4c6..a56f629 100644 --- a/kernel/rtmutex-tester.c +++ b/kernel/rtmutex-tester.c @@ -297,8 +297,8 @@ static int test_func(void *data) * * opcode:data */ -static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, - size_t count) +static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr, + const char *buf, size_t count) { struct sched_param schedpar; struct test_thread_data *td; @@ -360,7 +360,8 @@ static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, * @dev: thread to query * @buf: char buffer to be filled with thread status info */ -static ssize_t sysfs_test_status(struct sys_device *dev, char *buf) +static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr, + char *buf) { struct test_thread_data *td; struct task_struct *tsk; diff --git a/kernel/sched.c b/kernel/sched.c index 0cdb502..d897a52 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -70,10 +70,13 @@ #include <linux/bootmem.h> #include <linux/debugfs.h> #include <linux/ctype.h> +#include <linux/ftrace.h> #include <asm/tlb.h> #include <asm/irq_regs.h> +#include "sched_cpupri.h" + /* * Convert user-nice values [ -20 ... 0 ... 19 ] * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], @@ -198,14 +201,19 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); rt_b->rt_period_timer.function = sched_rt_period_timer; - rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; + rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; +} + +static inline int rt_bandwidth_enabled(void) +{ + return sysctl_sched_rt_runtime >= 0; } static void start_rt_bandwidth(struct rt_bandwidth *rt_b) { ktime_t now; - if (rt_b->rt_runtime == RUNTIME_INF) + if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF) return; if (hrtimer_active(&rt_b->rt_period_timer)) @@ -289,15 +297,15 @@ struct task_group root_task_group; static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); /* Default task group's cfs_rq on each cpu */ static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; -#endif +#endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; -#endif -#else +#endif /* CONFIG_RT_GROUP_SCHED */ +#else /* !CONFIG_USER_SCHED */ #define root_task_group init_task_group -#endif +#endif /* CONFIG_USER_SCHED */ /* task_group_lock serializes add/remove of task groups and also changes to * a task group's cpu shares. @@ -307,9 +315,9 @@ static DEFINE_SPINLOCK(task_group_lock); #ifdef CONFIG_FAIR_GROUP_SCHED #ifdef CONFIG_USER_SCHED # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) -#else +#else /* !CONFIG_USER_SCHED */ # define INIT_TASK_GROUP_LOAD NICE_0_LOAD -#endif +#endif /* CONFIG_USER_SCHED */ /* * A weight of 0 or 1 can cause arithmetics problems. @@ -363,6 +371,10 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #else static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } +static inline struct task_group *task_group(struct task_struct *p) +{ + return NULL; +} #endif /* CONFIG_GROUP_SCHED */ @@ -373,6 +385,7 @@ struct cfs_rq { u64 exec_clock; u64 min_vruntime; + u64 pair_start; struct rb_root tasks_timeline; struct rb_node *rb_leftmost; @@ -401,6 +414,31 @@ struct cfs_rq { */ struct list_head leaf_cfs_rq_list; struct task_group *tg; /* group that "owns" this runqueue */ + +#ifdef CONFIG_SMP + /* + * the part of load.weight contributed by tasks + */ + unsigned long task_weight; + + /* + * h_load = weight * f(tg) + * + * Where f(tg) is the recursive weight fraction assigned to + * this group. + */ + unsigned long h_load; + + /* + * this cpu's part of tg->shares + */ + unsigned long shares; + + /* + * load.weight at the time we set shares + */ + unsigned long rq_weight; +#endif #endif }; @@ -452,6 +490,9 @@ struct root_domain { */ cpumask_t rto_mask; atomic_t rto_count; +#ifdef CONFIG_SMP + struct cpupri cpupri; +#endif }; /* @@ -526,14 +567,19 @@ struct rq { int push_cpu; /* cpu of this runqueue: */ int cpu; + int online; + + unsigned long avg_load_per_task; struct task_struct *migration_thread; struct list_head migration_queue; #endif #ifdef CONFIG_SCHED_HRTICK - unsigned long hrtick_flags; - ktime_t hrtick_expire; +#ifdef CONFIG_SMP + int hrtick_csd_pending; + struct call_single_data hrtick_csd; +#endif struct hrtimer hrtick_timer; #endif @@ -559,14 +605,13 @@ struct rq { /* BKL stats */ unsigned int bkl_count; #endif - struct lock_class_key rq_lock_key; }; static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -static inline void check_preempt_curr(struct rq *rq, struct task_struct *p) +static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) { - rq->curr->sched_class->check_preempt_curr(rq, p); + rq->curr->sched_class->check_preempt_curr(rq, p, sync); } static inline int cpu_of(struct rq *rq) @@ -607,6 +652,24 @@ static inline void update_rq_clock(struct rq *rq) # define const_debug static const #endif +/** + * runqueue_is_locked + * + * Returns true if the current cpu runqueue is locked. + * This interface allows printk to be called with the runqueue lock + * held and know whether or not it is OK to wake up the klogd. + */ +int runqueue_is_locked(void) +{ + int cpu = get_cpu(); + struct rq *rq = cpu_rq(cpu); + int ret; + + ret = spin_is_locked(&rq->lock); + put_cpu(); + return ret; +} + /* * Debugging: various feature bits */ @@ -749,6 +812,12 @@ late_initcall(sched_init_debug); const_debug unsigned int sysctl_sched_nr_migrate = 32; /* + * ratelimit for updating the group shares. + * default: 0.25ms + */ +unsigned int sysctl_sched_shares_ratelimit = 250000; + +/* * period over which we measure -rt task cpu usage in us. * default: 1s */ @@ -769,88 +838,12 @@ static inline u64 global_rt_period(void) static inline u64 global_rt_runtime(void) { - if (sysctl_sched_rt_period < 0) + if (sysctl_sched_rt_runtime < 0) return RUNTIME_INF; return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; } -unsigned long long time_sync_thresh = 100000; - -static DEFINE_PER_CPU(unsigned long long, time_offset); -static DEFINE_PER_CPU(unsigned long long, prev_cpu_time); - -/* - * Global lock which we take every now and then to synchronize - * the CPUs time. This method is not warp-safe, but it's good - * enough to synchronize slowly diverging time sources and thus - * it's good enough for tracing: - */ -static DEFINE_SPINLOCK(time_sync_lock); -static unsigned long long prev_global_time; - -static unsigned long long __sync_cpu_clock(unsigned long long time, int cpu) -{ - /* - * We want this inlined, to not get tracer function calls - * in this critical section: - */ - spin_acquire(&time_sync_lock.dep_map, 0, 0, _THIS_IP_); - __raw_spin_lock(&time_sync_lock.raw_lock); - - if (time < prev_global_time) { - per_cpu(time_offset, cpu) += prev_global_time - time; - time = prev_global_time; - } else { - prev_global_time = time; - } - - __raw_spin_unlock(&time_sync_lock.raw_lock); - spin_release(&time_sync_lock.dep_map, 1, _THIS_IP_); - - return time; -} - -static unsigned long long __cpu_clock(int cpu) -{ - unsigned long long now; - - /* - * Only call sched_clock() if the scheduler has already been - * initialized (some code might call cpu_clock() very early): - */ - if (unlikely(!scheduler_running)) - return 0; - - now = sched_clock_cpu(cpu); - - return now; -} - -/* - * For kernel-internal use: high-speed (but slightly incorrect) per-cpu - * clock constructed from sched_clock(): - */ -unsigned long long cpu_clock(int cpu) -{ - unsigned long long prev_cpu_time, time, delta_time; - unsigned long flags; - - local_irq_save(flags); - prev_cpu_time = per_cpu(prev_cpu_time, cpu); - time = __cpu_clock(cpu) + per_cpu(time_offset, cpu); - delta_time = time-prev_cpu_time; - - if (unlikely(delta_time > time_sync_thresh)) { - time = __sync_cpu_clock(time, cpu); - per_cpu(prev_cpu_time, cpu) = time; - } - local_irq_restore(flags); - - return time; -} -EXPORT_SYMBOL_GPL(cpu_clock); - #ifndef prepare_arch_switch # define prepare_arch_switch(next) do { } while (0) #endif @@ -996,13 +989,6 @@ static struct rq *this_rq_lock(void) return rq; } -static void __resched_task(struct task_struct *p, int tif_bit); - -static inline void resched_task(struct task_struct *p) -{ - __resched_task(p, TIF_NEED_RESCHED); -} - #ifdef CONFIG_SCHED_HRTICK /* * Use HR-timers to deliver accurate preemption points. @@ -1014,25 +1000,6 @@ static inline void resched_task(struct task_struct *p) * When we get rescheduled we reprogram the hrtick_timer outside of the * rq->lock. */ -static inline void resched_hrt(struct task_struct *p) -{ - __resched_task(p, TIF_HRTICK_RESCHED); -} - -static inline void resched_rq(struct rq *rq) -{ - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - resched_task(rq->curr); - spin_unlock_irqrestore(&rq->lock, flags); -} - -enum { - HRTICK_SET, /* re-programm hrtick_timer */ - HRTICK_RESET, /* not a new slice */ - HRTICK_BLOCK, /* stop hrtick operations */ -}; /* * Use hrtick when: @@ -1043,40 +1010,11 @@ static inline int hrtick_enabled(struct rq *rq) { if (!sched_feat(HRTICK)) return 0; - if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags))) + if (!cpu_active(cpu_of(rq))) return 0; return hrtimer_is_hres_active(&rq->hrtick_timer); } -/* - * Called to set the hrtick timer state. - * - * called with rq->lock held and irqs disabled - */ -static void hrtick_start(struct rq *rq, u64 delay, int reset) -{ - assert_spin_locked(&rq->lock); - - /* - * preempt at: now + delay - */ - rq->hrtick_expire = - ktime_add_ns(rq->hrtick_timer.base->get_time(), delay); - /* - * indicate we need to program the timer - */ - __set_bit(HRTICK_SET, &rq->hrtick_flags); - if (reset) - __set_bit(HRTICK_RESET, &rq->hrtick_flags); - - /* - * New slices are called from the schedule path and don't need a - * forced reschedule. - */ - if (reset) - resched_hrt(rq->curr); -} - static void hrtick_clear(struct rq *rq) { if (hrtimer_active(&rq->hrtick_timer)) @@ -1084,32 +1022,6 @@ static void hrtick_clear(struct rq *rq) } /* - * Update the timer from the possible pending state. - */ -static void hrtick_set(struct rq *rq) -{ - ktime_t time; - int set, reset; - unsigned long flags; - - WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); - - spin_lock_irqsave(&rq->lock, flags); - set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags); - reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags); - time = rq->hrtick_expire; - clear_thread_flag(TIF_HRTICK_RESCHED); - spin_unlock_irqrestore(&rq->lock, flags); - - if (set) { - hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS); - if (reset && !hrtimer_active(&rq->hrtick_timer)) - resched_rq(rq); - } else - hrtick_clear(rq); -} - -/* * High-resolution timer tick. * Runs from hardirq context with interrupts disabled. */ @@ -1128,27 +1040,37 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer) } #ifdef CONFIG_SMP -static void hotplug_hrtick_disable(int cpu) +/* + * called from hardirq (IPI) context + */ +static void __hrtick_start(void *arg) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; + struct rq *rq = arg; - spin_lock_irqsave(&rq->lock, flags); - rq->hrtick_flags = 0; - __set_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); - - hrtick_clear(rq); + spin_lock(&rq->lock); + hrtimer_restart(&rq->hrtick_timer); + rq->hrtick_csd_pending = 0; + spin_unlock(&rq->lock); } -static void hotplug_hrtick_enable(int cpu) +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; + struct hrtimer *timer = &rq->hrtick_timer; + ktime_t time = ktime_add_ns(timer->base->get_time(), delay); - spin_lock_irqsave(&rq->lock, flags); - __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); + timer->expires = time; + + if (rq == this_rq()) { + hrtimer_restart(timer); + } else if (!rq->hrtick_csd_pending) { + __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); + rq->hrtick_csd_pending = 1; + } } static int @@ -1163,70 +1085,60 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DOWN_PREPARE_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: - hotplug_hrtick_disable(cpu); - return NOTIFY_OK; - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hotplug_hrtick_enable(cpu); + hrtick_clear(cpu_rq(cpu)); return NOTIFY_OK; } return NOTIFY_DONE; } -static void init_hrtick(void) +static __init void init_hrtick(void) { hotcpu_notifier(hotplug_hrtick, 0); } -#endif /* CONFIG_SMP */ +#else +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) +{ + hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); +} -static void init_rq_hrtick(struct rq *rq) +static inline void init_hrtick(void) { - rq->hrtick_flags = 0; - hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rq->hrtick_timer.function = hrtick; - rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; } +#endif /* CONFIG_SMP */ -void hrtick_resched(void) +static void init_rq_hrtick(struct rq *rq) { - struct rq *rq; - unsigned long flags; +#ifdef CONFIG_SMP + rq->hrtick_csd_pending = 0; - if (!test_thread_flag(TIF_HRTICK_RESCHED)) - return; + rq->hrtick_csd.flags = 0; + rq->hrtick_csd.func = __hrtick_start; + rq->hrtick_csd.info = rq; +#endif - local_irq_save(flags); - rq = cpu_rq(smp_processor_id()); - hrtick_set(rq); - local_irq_restore(flags); + hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + rq->hrtick_timer.function = hrtick; + rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU; } -#else +#else /* CONFIG_SCHED_HRTICK */ static inline void hrtick_clear(struct rq *rq) { } -static inline void hrtick_set(struct rq *rq) -{ -} - static inline void init_rq_hrtick(struct rq *rq) { } -void hrtick_resched(void) -{ -} - static inline void init_hrtick(void) { } -#endif +#endif /* CONFIG_SCHED_HRTICK */ /* * resched_task - mark a task 'to be rescheduled now'. @@ -1241,16 +1153,16 @@ static inline void init_hrtick(void) #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) #endif -static void __resched_task(struct task_struct *p, int tif_bit) +static void resched_task(struct task_struct *p) { int cpu; assert_spin_locked(&task_rq(p)->lock); - if (unlikely(test_tsk_thread_flag(p, tif_bit))) + if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) return; - set_tsk_thread_flag(p, tif_bit); + set_tsk_thread_flag(p, TIF_NEED_RESCHED); cpu = task_cpu(p); if (cpu == smp_processor_id()) @@ -1313,15 +1225,15 @@ void wake_up_idle_cpu(int cpu) if (!tsk_is_polling(rq->idle)) smp_send_reschedule(cpu); } -#endif +#endif /* CONFIG_NO_HZ */ -#else -static void __resched_task(struct task_struct *p, int tif_bit) +#else /* !CONFIG_SMP */ +static void resched_task(struct task_struct *p) { assert_spin_locked(&task_rq(p)->lock); - set_tsk_thread_flag(p, tif_bit); + set_tsk_need_resched(p); } -#endif +#endif /* CONFIG_SMP */ #if BITS_PER_LONG == 32 # define WMULT_CONST (~0UL) @@ -1336,6 +1248,9 @@ static void __resched_task(struct task_struct *p, int tif_bit) */ #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) +/* + * delta *= weight / lw + */ static unsigned long calc_delta_mine(unsigned long delta_exec, unsigned long weight, struct load_weight *lw) @@ -1363,12 +1278,6 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight, return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); } -static inline unsigned long -calc_delta_fair(unsigned long delta_exec, struct load_weight *lw) -{ - return calc_delta_mine(delta_exec, NICE_0_LOAD, lw); -} - static inline void update_load_add(struct load_weight *lw, unsigned long inc) { lw->weight += inc; @@ -1476,20 +1385,227 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load) update_load_sub(&rq->load, load); } +#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) +typedef int (*tg_visitor)(struct task_group *, void *); + +/* + * Iterate the full tree, calling @down when first entering a node and @up when + * leaving it for the final time. + */ +static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) +{ + struct task_group *parent, *child; + int ret; + + rcu_read_lock(); + parent = &root_task_group; +down: + ret = (*down)(parent, data); + if (ret) + goto out_unlock; + list_for_each_entry_rcu(child, &parent->children, siblings) { + parent = child; + goto down; + +up: + continue; + } + ret = (*up)(parent, data); + if (ret) + goto out_unlock; + + child = parent; + parent = parent->parent; + if (parent) + goto up; +out_unlock: + rcu_read_unlock(); + + return ret; +} + +static int tg_nop(struct task_group *tg, void *data) +{ + return 0; +} +#endif + #ifdef CONFIG_SMP static unsigned long source_load(int cpu, int type); static unsigned long target_load(int cpu, int type); -static unsigned long cpu_avg_load_per_task(int cpu); static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); -#else /* CONFIG_SMP */ + +static unsigned long cpu_avg_load_per_task(int cpu) +{ + struct rq *rq = cpu_rq(cpu); + + if (rq->nr_running) + rq->avg_load_per_task = rq->load.weight / rq->nr_running; + + return rq->avg_load_per_task; +} #ifdef CONFIG_FAIR_GROUP_SCHED -static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) + +static void __set_se_shares(struct sched_entity *se, unsigned long shares); + +/* + * Calculate and set the cpu's group shares. + */ +static void +__update_group_shares_cpu(struct task_group *tg, int cpu, + unsigned long sd_shares, unsigned long sd_rq_weight) +{ + int boost = 0; + unsigned long shares; + unsigned long rq_weight; + + if (!tg->se[cpu]) + return; + + rq_weight = tg->cfs_rq[cpu]->load.weight; + + /* + * If there are currently no tasks on the cpu pretend there is one of + * average load so that when a new task gets to run here it will not + * get delayed by group starvation. + */ + if (!rq_weight) { + boost = 1; + rq_weight = NICE_0_LOAD; + } + + if (unlikely(rq_weight > sd_rq_weight)) + rq_weight = sd_rq_weight; + + /* + * \Sum shares * rq_weight + * shares = ----------------------- + * \Sum rq_weight + * + */ + shares = (sd_shares * rq_weight) / (sd_rq_weight + 1); + + /* + * record the actual number of shares, not the boosted amount. + */ + tg->cfs_rq[cpu]->shares = boost ? 0 : shares; + tg->cfs_rq[cpu]->rq_weight = rq_weight; + + if (shares < MIN_SHARES) + shares = MIN_SHARES; + else if (shares > MAX_SHARES) + shares = MAX_SHARES; + + __set_se_shares(tg->se[cpu], shares); +} + +/* + * Re-compute the task group their per cpu shares over the given domain. + * This needs to be done in a bottom-up fashion because the rq weight of a + * parent group depends on the shares of its child groups. + */ +static int tg_shares_up(struct task_group *tg, void *data) +{ + unsigned long rq_weight = 0; + unsigned long shares = 0; + struct sched_domain *sd = data; + int i; + + for_each_cpu_mask(i, sd->span) { + rq_weight += tg->cfs_rq[i]->load.weight; + shares += tg->cfs_rq[i]->shares; + } + + if ((!shares && rq_weight) || shares > tg->shares) + shares = tg->shares; + + if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) + shares = tg->shares; + + if (!rq_weight) + rq_weight = cpus_weight(sd->span) * NICE_0_LOAD; + + for_each_cpu_mask(i, sd->span) { + struct rq *rq = cpu_rq(i); + unsigned long flags; + + spin_lock_irqsave(&rq->lock, flags); + __update_group_shares_cpu(tg, i, shares, rq_weight); + spin_unlock_irqrestore(&rq->lock, flags); + } + + return 0; +} + +/* + * Compute the cpu's hierarchical load factor for each task group. + * This needs to be done in a top-down fashion because the load of a child + * group is a fraction of its parents load. + */ +static int tg_load_down(struct task_group *tg, void *data) +{ + unsigned long load; + long cpu = (long)data; + + if (!tg->parent) { + load = cpu_rq(cpu)->load.weight; + } else { + load = tg->parent->cfs_rq[cpu]->h_load; + load *= tg->cfs_rq[cpu]->shares; + load /= tg->parent->cfs_rq[cpu]->load.weight + 1; + } + + tg->cfs_rq[cpu]->h_load = load; + + return 0; +} + +static void update_shares(struct sched_domain *sd) +{ + u64 now = cpu_clock(raw_smp_processor_id()); + s64 elapsed = now - sd->last_update; + + if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { + sd->last_update = now; + walk_tg_tree(tg_nop, tg_shares_up, sd); + } +} + +static void update_shares_locked(struct rq *rq, struct sched_domain *sd) +{ + spin_unlock(&rq->lock); + update_shares(sd); + spin_lock(&rq->lock); +} + +static void update_h_load(long cpu) +{ + walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); +} + +#else + +static inline void update_shares(struct sched_domain *sd) +{ +} + +static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) { } + #endif -#endif /* CONFIG_SMP */ +#endif + +#ifdef CONFIG_FAIR_GROUP_SCHED +static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) +{ +#ifdef CONFIG_SMP + cfs_rq->shares = shares; +#endif +} +#endif #include "sched_stats.h" #include "sched_idletask.c" @@ -1500,27 +1616,17 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) #endif #define sched_class_highest (&rt_sched_class) +#define for_each_class(class) \ + for (class = sched_class_highest; class; class = class->next) -static inline void inc_load(struct rq *rq, const struct task_struct *p) -{ - update_load_add(&rq->load, p->se.load.weight); -} - -static inline void dec_load(struct rq *rq, const struct task_struct *p) -{ - update_load_sub(&rq->load, p->se.load.weight); -} - -static void inc_nr_running(struct task_struct *p, struct rq *rq) +static void inc_nr_running(struct rq *rq) { rq->nr_running++; - inc_load(rq, p); } -static void dec_nr_running(struct task_struct *p, struct rq *rq) +static void dec_nr_running(struct rq *rq) { rq->nr_running--; - dec_load(rq, p); } static void set_load_weight(struct task_struct *p) @@ -1544,6 +1650,12 @@ static void set_load_weight(struct task_struct *p) p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; } +static void update_avg(u64 *avg, u64 sample) +{ + s64 diff = sample - *avg; + *avg += diff >> 3; +} + static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) { sched_info_queued(p); @@ -1553,6 +1665,13 @@ static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) { + if (sleep && p->se.last_wakeup) { + update_avg(&p->se.avg_overlap, + p->se.sum_exec_runtime - p->se.last_wakeup); + p->se.last_wakeup = 0; + } + + sched_info_dequeued(p); p->sched_class->dequeue_task(rq, p, sleep); p->se.on_rq = 0; } @@ -1612,7 +1731,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) rq->nr_uninterruptible--; enqueue_task(rq, p, wakeup); - inc_nr_running(p, rq); + inc_nr_running(rq); } /* @@ -1624,7 +1743,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) rq->nr_uninterruptible++; dequeue_task(rq, p, sleep); - dec_nr_running(p, rq); + dec_nr_running(rq); } /** @@ -1636,12 +1755,6 @@ inline int task_curr(const struct task_struct *p) return cpu_curr(task_cpu(p)) == p; } -/* Used instead of source_load when we know the type == 0 */ -unsigned long weighted_cpuload(const int cpu) -{ - return cpu_rq(cpu)->load.weight; -} - static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) { set_task_rq(p, cpu); @@ -1670,6 +1783,12 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p, #ifdef CONFIG_SMP +/* Used instead of source_load when we know the type == 0 */ +static unsigned long weighted_cpuload(const int cpu) +{ + return cpu_rq(cpu)->load.weight; +} + /* * Is this task likely cache-hot: */ @@ -1765,16 +1884,24 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) /* * wait_task_inactive - wait for a thread to unschedule. * + * If @match_state is nonzero, it's the @p->state value just checked and + * not expected to change. If it changes, i.e. @p might have woken up, + * then return zero. When we succeed in waiting for @p to be off its CPU, + * we return a positive number (its total switch count). If a second call + * a short while later returns the same number, the caller can be sure that + * @p has remained unscheduled the whole time. + * * The caller must ensure that the task *will* unschedule sometime soon, * else this function might spin for a *long* time. This function can't * be called with interrupts off, or it may introduce deadlock with * smp_call_function() if an IPI is sent by the same process we are * waiting to become inactive. */ -void wait_task_inactive(struct task_struct *p) +unsigned long wait_task_inactive(struct task_struct *p, long match_state) { unsigned long flags; int running, on_rq; + unsigned long ncsw; struct rq *rq; for (;;) { @@ -1797,8 +1924,11 @@ void wait_task_inactive(struct task_struct *p) * return false if the runqueue has changed and p * is actually now running somewhere else! */ - while (task_running(rq, p)) + while (task_running(rq, p)) { + if (match_state && unlikely(p->state != match_state)) + return 0; cpu_relax(); + } /* * Ok, time to look more closely! We need the rq @@ -1808,9 +1938,18 @@ void wait_task_inactive(struct task_struct *p) rq = task_rq_lock(p, &flags); running = task_running(rq, p); on_rq = p->se.on_rq; + ncsw = 0; + if (!match_state || p->state == match_state) + ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ task_rq_unlock(rq, &flags); /* + * If it changed from the expected state, bail out now. + */ + if (unlikely(!ncsw)) + break; + + /* * Was it really running after all now that we * checked with the proper locks actually held? * @@ -1842,6 +1981,8 @@ void wait_task_inactive(struct task_struct *p) */ break; } + + return ncsw; } /*** @@ -1880,7 +2021,7 @@ static unsigned long source_load(int cpu, int type) struct rq *rq = cpu_rq(cpu); unsigned long total = weighted_cpuload(cpu); - if (type == 0) + if (type == 0 || !sched_feat(LB_BIAS)) return total; return min(rq->cpu_load[type-1], total); @@ -1895,25 +2036,13 @@ static unsigned long target_load(int cpu, int type) struct rq *rq = cpu_rq(cpu); unsigned long total = weighted_cpuload(cpu); - if (type == 0) + if (type == 0 || !sched_feat(LB_BIAS)) return total; return max(rq->cpu_load[type-1], total); } /* - * Return the average load per task on the cpu's run queue - */ -static unsigned long cpu_avg_load_per_task(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - unsigned long n = rq->nr_running; - - return n ? total / n : SCHED_LOAD_SCALE; -} - -/* * find_idlest_group finds and returns the least busy CPU group within the * domain. */ @@ -1939,7 +2068,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) /* Tally up the load of all CPUs in the group */ avg_load = 0; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { /* Bias balancing toward cpus of our domain */ if (local_group) load = source_load(i, load_idx); @@ -1981,7 +2110,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu, /* Traverse only the allowed CPUs */ cpus_and(*tmp, group->cpumask, p->cpus_allowed); - for_each_cpu_mask(i, *tmp) { + for_each_cpu_mask_nr(i, *tmp) { load = weighted_cpuload(i); if (load < min_load || (load == min_load && i == this_cpu)) { @@ -2019,6 +2148,9 @@ static int sched_balance_self(int cpu, int flag) sd = tmp; } + if (sd) + update_shares(sd); + while (sd) { cpumask_t span, tmpmask; struct sched_group *group; @@ -2085,6 +2217,22 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (!sched_feat(SYNC_WAKEUPS)) sync = 0; +#ifdef CONFIG_SMP + if (sched_feat(LB_WAKEUP_UPDATE)) { + struct sched_domain *sd; + + this_cpu = raw_smp_processor_id(); + cpu = task_cpu(p); + + for_each_domain(this_cpu, sd) { + if (cpu_isset(cpu, sd->span)) { + update_shares(sd); + break; + } + } + } +#endif + smp_wmb(); rq = task_rq_lock(p, &flags); old_state = p->state; @@ -2131,7 +2279,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) } } } -#endif +#endif /* CONFIG_SCHEDSTATS */ out_activate: #endif /* CONFIG_SMP */ @@ -2149,7 +2297,10 @@ out_activate: success = 1; out_running: - check_preempt_curr(rq, p); + trace_mark(kernel_sched_wakeup, + "pid %d state %ld ## rq %p task %p rq->curr %p", + p->pid, p->state, rq, p, rq->curr); + check_preempt_curr(rq, p, sync); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -2157,6 +2308,8 @@ out_running: p->sched_class->task_wake_up(rq, p); #endif out: + current->se.last_wakeup = current->se.sum_exec_runtime; + task_rq_unlock(rq, &flags); return success; @@ -2277,9 +2430,12 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) * management (if any): */ p->sched_class->task_new(rq, p); - inc_nr_running(p, rq); + inc_nr_running(rq); } - check_preempt_curr(rq, p); + trace_mark(kernel_sched_wakeup_new, + "pid %d state %ld ## rq %p task %p rq->curr %p", + p->pid, p->state, rq, p, rq->curr); + check_preempt_curr(rq, p, 0); #ifdef CONFIG_SMP if (p->sched_class->task_wake_up) p->sched_class->task_wake_up(rq, p); @@ -2331,7 +2487,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr, notifier->ops->sched_out(notifier, next); } -#else +#else /* !CONFIG_PREEMPT_NOTIFIERS */ static void fire_sched_in_preempt_notifiers(struct task_struct *curr) { @@ -2343,7 +2499,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr, { } -#endif +#endif /* CONFIG_PREEMPT_NOTIFIERS */ /** * prepare_task_switch - prepare to switch tasks @@ -2451,6 +2607,11 @@ context_switch(struct rq *rq, struct task_struct *prev, struct mm_struct *mm, *oldmm; prepare_task_switch(rq, prev, next); + trace_mark(kernel_sched_schedule, + "prev_pid %d next_pid %d prev_state %ld " + "## rq %p prev %p next %p", + prev->pid, next->pid, prev->state, + rq, prev, next); mm = next->mm; oldmm = prev->active_mm; /* @@ -2612,10 +2773,10 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2) } else { if (rq1 < rq2) { spin_lock(&rq1->lock); - spin_lock(&rq2->lock); + spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); } else { spin_lock(&rq2->lock); - spin_lock(&rq1->lock); + spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); } } update_rq_clock(rq1); @@ -2658,14 +2819,21 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest) if (busiest < this_rq) { spin_unlock(&this_rq->lock); spin_lock(&busiest->lock); - spin_lock(&this_rq->lock); + spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); ret = 1; } else - spin_lock(&busiest->lock); + spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); } return ret; } +static void double_unlock_balance(struct rq *this_rq, struct rq *busiest) + __releases(busiest->lock) +{ + spin_unlock(&busiest->lock); + lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); +} + /* * If dest_cpu is allowed for this process, migrate the task to it. * This is accomplished by forcing the cpu_allowed mask to only @@ -2680,7 +2848,7 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu) rq = task_rq_lock(p, &flags); if (!cpu_isset(dest_cpu, p->cpus_allowed) - || unlikely(cpu_is_offline(dest_cpu))) + || unlikely(!cpu_active(dest_cpu))) goto out; /* force the process onto the specified CPU */ @@ -2727,7 +2895,7 @@ static void pull_task(struct rq *src_rq, struct task_struct *p, * Note that idle threads have a prio of MAX_PRIO, for this test * to be always true for them. */ - check_preempt_curr(this_rq, p); + check_preempt_curr(this_rq, p, 0); } /* @@ -2785,7 +2953,7 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio, struct rq_iterator *iterator) { - int loops = 0, pulled = 0, pinned = 0, skip_for_load; + int loops = 0, pulled = 0, pinned = 0; struct task_struct *p; long rem_load_move = max_load_move; @@ -2801,14 +2969,8 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, next: if (!p || loops++ > sysctl_sched_nr_migrate) goto out; - /* - * To help distribute high priority tasks across CPUs we don't - * skip a task if it will be the highest priority task (i.e. smallest - * prio value) on its new queue regardless of its load weight - */ - skip_for_load = (p->se.load.weight >> 1) > rem_load_move + - SCHED_LOAD_SCALE_FUZZ; - if ((skip_for_load && p->prio >= *this_best_prio) || + + if ((p->se.load.weight >> 1) > rem_load_move || !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { p = iterator->next(iterator->arg); goto next; @@ -2863,6 +3025,10 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, max_load_move - total_load_moved, sd, idle, all_pinned, &this_best_prio); class = class->next; + + if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) + break; + } while (class && max_load_move > total_load_moved); return total_load_moved > 0; @@ -2939,6 +3105,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, max_load = this_load = total_load = total_pwr = 0; busiest_load_per_task = busiest_nr_running = 0; this_load_per_task = this_nr_running = 0; + if (idle == CPU_NOT_IDLE) load_idx = sd->busy_idx; else if (idle == CPU_NEWLY_IDLE) @@ -2953,6 +3120,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, int __group_imb = 0; unsigned int balance_cpu = -1, first_idle_cpu = 0; unsigned long sum_nr_running, sum_weighted_load; + unsigned long sum_avg_load_per_task; + unsigned long avg_load_per_task; local_group = cpu_isset(this_cpu, group->cpumask); @@ -2961,10 +3130,12 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, /* Tally up the load of all CPUs in the group */ sum_weighted_load = sum_nr_running = avg_load = 0; + sum_avg_load_per_task = avg_load_per_task = 0; + max_cpu_load = 0; min_cpu_load = ~0UL; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { struct rq *rq; if (!cpu_isset(i, *cpus)) @@ -2994,6 +3165,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, avg_load += load; sum_nr_running += rq->nr_running; sum_weighted_load += weighted_cpuload(i); + + sum_avg_load_per_task += cpu_avg_load_per_task(i); } /* @@ -3015,7 +3188,20 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, avg_load = sg_div_cpu_power(group, avg_load * SCHED_LOAD_SCALE); - if ((max_cpu_load - min_cpu_load) > SCHED_LOAD_SCALE) + + /* + * Consider the group unbalanced when the imbalance is larger + * than the average weight of two tasks. + * + * APZ: with cgroup the avg task weight can vary wildly and + * might not be a suitable number - should we keep a + * normalized nr_running number somewhere that negates + * the hierarchy? + */ + avg_load_per_task = sg_div_cpu_power(group, + sum_avg_load_per_task * SCHED_LOAD_SCALE); + + if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) __group_imb = 1; group_capacity = group->__cpu_power / SCHED_LOAD_SCALE; @@ -3156,9 +3342,9 @@ small_imbalance: if (busiest_load_per_task > this_load_per_task) imbn = 1; } else - this_load_per_task = SCHED_LOAD_SCALE; + this_load_per_task = cpu_avg_load_per_task(this_cpu); - if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >= + if (max_load - this_load + 2*busiest_load_per_task >= busiest_load_per_task * imbn) { *imbalance = busiest_load_per_task; return busiest; @@ -3228,7 +3414,7 @@ find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, unsigned long max_load = 0; int i; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { unsigned long wl; if (!cpu_isset(i, *cpus)) @@ -3284,6 +3470,7 @@ static int load_balance(int this_cpu, struct rq *this_rq, schedstat_inc(sd, lb_count[idle]); redo: + update_shares(sd); group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, cpus, balance); @@ -3386,8 +3573,9 @@ redo: if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - return -1; - return ld_moved; + ld_moved = -1; + + goto out; out_balanced: schedstat_inc(sd, lb_balanced[idle]); @@ -3402,8 +3590,13 @@ out_one_pinned: if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) - return -1; - return 0; + ld_moved = -1; + else + ld_moved = 0; +out: + if (ld_moved) + update_shares(sd); + return ld_moved; } /* @@ -3438,6 +3631,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd, schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); redo: + update_shares_locked(this_rq, sd); group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, &sd_idle, cpus, NULL); if (!group) { @@ -3464,7 +3658,7 @@ redo: ld_moved = move_tasks(this_rq, this_cpu, busiest, imbalance, sd, CPU_NEWLY_IDLE, &all_pinned); - spin_unlock(&busiest->lock); + double_unlock_balance(this_rq, busiest); if (unlikely(all_pinned)) { cpu_clear(cpu_of(busiest), *cpus); @@ -3481,6 +3675,7 @@ redo: } else sd->nr_balance_failed = 0; + update_shares_locked(this_rq, sd); return ld_moved; out_balanced: @@ -3578,7 +3773,7 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) else schedstat_inc(sd, alb_failed); } - spin_unlock(&target_rq->lock); + double_unlock_balance(busiest_rq, target_rq); } #ifdef CONFIG_NO_HZ @@ -3621,7 +3816,7 @@ int select_nohz_load_balancer(int stop_tick) /* * If we are going offline and still the leader, give up! */ - if (cpu_is_offline(cpu) && + if (!cpu_active(cpu) && atomic_read(&nohz.load_balancer) == cpu) { if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) BUG(); @@ -3672,6 +3867,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) /* Earliest time when we have to do rebalance again */ unsigned long next_balance = jiffies + 60*HZ; int update_next_balance = 0; + int need_serialize; cpumask_t tmp; for_each_domain(cpu, sd) { @@ -3689,8 +3885,9 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) if (interval > HZ*NR_CPUS/10) interval = HZ*NR_CPUS/10; + need_serialize = sd->flags & SD_SERIALIZE; - if (sd->flags & SD_SERIALIZE) { + if (need_serialize) { if (!spin_trylock(&balancing)) goto out; } @@ -3706,7 +3903,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) } sd->last_balance = jiffies; } - if (sd->flags & SD_SERIALIZE) + if (need_serialize) spin_unlock(&balancing); out: if (time_after(next_balance, sd->last_balance + interval)) { @@ -3759,7 +3956,7 @@ static void run_rebalance_domains(struct softirq_action *h) int balance_cpu; cpu_clear(this_cpu, cpus); - for_each_cpu_mask(balance_cpu, cpus) { + for_each_cpu_mask_nr(balance_cpu, cpus) { /* * If this cpu gets work to do, stop the load balancing * work being done for other cpus. Next load @@ -3895,6 +4092,8 @@ void account_user_time(struct task_struct *p, cputime_t cputime) cpustat->nice = cputime64_add(cpustat->nice, tmp); else cpustat->user = cputime64_add(cpustat->user, tmp); + /* Account for user time used */ + acct_update_integrals(p); } /* @@ -3995,6 +4194,65 @@ void account_steal_time(struct task_struct *p, cputime_t steal) } /* + * Use precise platform statistics if available: + */ +#ifdef CONFIG_VIRT_CPU_ACCOUNTING +cputime_t task_utime(struct task_struct *p) +{ + return p->utime; +} + +cputime_t task_stime(struct task_struct *p) +{ + return p->stime; +} +#else +cputime_t task_utime(struct task_struct *p) +{ + clock_t utime = cputime_to_clock_t(p->utime), + total = utime + cputime_to_clock_t(p->stime); + u64 temp; + + /* + * Use CFS's precise accounting: + */ + temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); + + if (total) { + temp *= utime; + do_div(temp, total); + } + utime = (clock_t)temp; + + p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); + return p->prev_utime; +} + +cputime_t task_stime(struct task_struct *p) +{ + clock_t stime; + + /* + * Use CFS's precise accounting. (we subtract utime from + * the total, to make sure the total observed by userspace + * grows monotonically - apps rely on that): + */ + stime = nsec_to_clock_t(p->se.sum_exec_runtime) - + cputime_to_clock_t(task_utime(p)); + + if (stime >= 0) + p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); + + return p->prev_stime; +} +#endif + +inline cputime_t task_gtime(struct task_struct *p) +{ + return p->gtime; +} + +/* * This function gets called by the timer code, with HZ frequency. * We call it with interrupts disabled. * @@ -4021,26 +4279,44 @@ void scheduler_tick(void) #endif } -#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT) +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ + defined(CONFIG_PREEMPT_TRACER)) + +static inline unsigned long get_parent_ip(unsigned long addr) +{ + if (in_lock_functions(addr)) { + addr = CALLER_ADDR2; + if (in_lock_functions(addr)) + addr = CALLER_ADDR3; + } + return addr; +} void __kprobes add_preempt_count(int val) { +#ifdef CONFIG_DEBUG_PREEMPT /* * Underflow? */ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) return; +#endif preempt_count() += val; +#ifdef CONFIG_DEBUG_PREEMPT /* * Spinlock count overflowing soon? */ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= PREEMPT_MASK - 10); +#endif + if (preempt_count() == val) + trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); } EXPORT_SYMBOL(add_preempt_count); void __kprobes sub_preempt_count(int val) { +#ifdef CONFIG_DEBUG_PREEMPT /* * Underflow? */ @@ -4052,7 +4328,10 @@ void __kprobes sub_preempt_count(int val) if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && !(preempt_count() & PREEMPT_MASK))) return; +#endif + if (preempt_count() == val) + trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); preempt_count() -= val; } EXPORT_SYMBOL(sub_preempt_count); @@ -4070,6 +4349,7 @@ static noinline void __schedule_bug(struct task_struct *prev) prev->comm, prev->pid, preempt_count()); debug_show_held_locks(prev); + print_modules(); if (irqs_disabled()) print_irqtrace_events(prev); @@ -4158,7 +4438,8 @@ need_resched_nonpreemptible: schedule_debug(prev); - hrtick_clear(rq); + if (sched_feat(HRTICK)) + hrtick_clear(rq); /* * Do the rq-clock update outside the rq lock: @@ -4204,8 +4485,6 @@ need_resched_nonpreemptible: } else spin_unlock_irq(&rq->lock); - hrtick_set(rq); - if (unlikely(reacquire_kernel_lock(current) < 0)) goto need_resched_nonpreemptible; @@ -4363,6 +4642,15 @@ __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) } EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ +/** + * complete: - signals a single thread waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up a single thread waiting on this completion. Threads will be + * awakened in the same order in which they were queued. + * + * See also complete_all(), wait_for_completion() and related routines. + */ void complete(struct completion *x) { unsigned long flags; @@ -4374,6 +4662,12 @@ void complete(struct completion *x) } EXPORT_SYMBOL(complete); +/** + * complete_all: - signals all threads waiting on this completion + * @x: holds the state of this particular completion + * + * This will wake up all threads waiting on this particular completion event. + */ void complete_all(struct completion *x) { unsigned long flags; @@ -4394,10 +4688,7 @@ do_wait_for_common(struct completion *x, long timeout, int state) wait.flags |= WQ_FLAG_EXCLUSIVE; __add_wait_queue_tail(&x->wait, &wait); do { - if ((state == TASK_INTERRUPTIBLE && - signal_pending(current)) || - (state == TASK_KILLABLE && - fatal_signal_pending(current))) { + if (signal_pending_state(state, current)) { timeout = -ERESTARTSYS; break; } @@ -4425,12 +4716,31 @@ wait_for_common(struct completion *x, long timeout, int state) return timeout; } +/** + * wait_for_completion: - waits for completion of a task + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It is NOT + * interruptible and there is no timeout. + * + * See also similar routines (i.e. wait_for_completion_timeout()) with timeout + * and interrupt capability. Also see complete(). + */ void __sched wait_for_completion(struct completion *x) { wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(wait_for_completion); +/** + * wait_for_completion_timeout: - waits for completion of a task (w/timeout) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. The timeout is in jiffies. It is not + * interruptible. + */ unsigned long __sched wait_for_completion_timeout(struct completion *x, unsigned long timeout) { @@ -4438,6 +4748,13 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout) } EXPORT_SYMBOL(wait_for_completion_timeout); +/** + * wait_for_completion_interruptible: - waits for completion of a task (w/intr) + * @x: holds the state of this particular completion + * + * This waits for completion of a specific task to be signaled. It is + * interruptible. + */ int __sched wait_for_completion_interruptible(struct completion *x) { long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); @@ -4447,6 +4764,14 @@ int __sched wait_for_completion_interruptible(struct completion *x) } EXPORT_SYMBOL(wait_for_completion_interruptible); +/** + * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) + * @x: holds the state of this particular completion + * @timeout: timeout value in jiffies + * + * This waits for either a completion of a specific task to be signaled or for a + * specified timeout to expire. It is interruptible. The timeout is in jiffies. + */ unsigned long __sched wait_for_completion_interruptible_timeout(struct completion *x, unsigned long timeout) @@ -4455,6 +4780,13 @@ wait_for_completion_interruptible_timeout(struct completion *x, } EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); +/** + * wait_for_completion_killable: - waits for completion of a task (killable) + * @x: holds the state of this particular completion + * + * This waits to be signaled for completion of a specific task. It can be + * interrupted by a kill signal. + */ int __sched wait_for_completion_killable(struct completion *x) { long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); @@ -4464,6 +4796,52 @@ int __sched wait_for_completion_killable(struct completion *x) } EXPORT_SYMBOL(wait_for_completion_killable); +/** + * try_wait_for_completion - try to decrement a completion without blocking + * @x: completion structure + * + * Returns: 0 if a decrement cannot be done without blocking + * 1 if a decrement succeeded. + * + * If a completion is being used as a counting completion, + * attempt to decrement the counter without blocking. This + * enables us to avoid waiting if the resource the completion + * is protecting is not available. + */ +bool try_wait_for_completion(struct completion *x) +{ + int ret = 1; + + spin_lock_irq(&x->wait.lock); + if (!x->done) + ret = 0; + else + x->done--; + spin_unlock_irq(&x->wait.lock); + return ret; +} +EXPORT_SYMBOL(try_wait_for_completion); + +/** + * completion_done - Test to see if a completion has any waiters + * @x: completion structure + * + * Returns: 0 if there are waiters (wait_for_completion() in progress) + * 1 if there are no waiters. + * + */ +bool completion_done(struct completion *x) +{ + int ret = 1; + + spin_lock_irq(&x->wait.lock); + if (!x->done) + ret = 0; + spin_unlock_irq(&x->wait.lock); + return ret; +} +EXPORT_SYMBOL(completion_done); + static long __sched sleep_on_common(wait_queue_head_t *q, int state, long timeout) { @@ -4586,10 +4964,8 @@ void set_user_nice(struct task_struct *p, long nice) goto out_unlock; } on_rq = p->se.on_rq; - if (on_rq) { + if (on_rq) dequeue_task(rq, p, 0); - dec_load(rq, p); - } p->static_prio = NICE_TO_PRIO(nice); set_load_weight(p); @@ -4599,7 +4975,6 @@ void set_user_nice(struct task_struct *p, long nice) if (on_rq) { enqueue_task(rq, p, 0); - inc_load(rq, p); /* * If the task increased its priority or is running and * lowered its priority, then reschedule its CPU: @@ -4744,16 +5119,8 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) set_load_weight(p); } -/** - * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. - * @p: the task in question. - * @policy: new policy. - * @param: structure containing the new RT priority. - * - * NOTE that the task may be already dead. - */ -int sched_setscheduler(struct task_struct *p, int policy, - struct sched_param *param) +static int __sched_setscheduler(struct task_struct *p, int policy, + struct sched_param *param, bool user) { int retval, oldprio, oldpolicy = -1, on_rq, running; unsigned long flags; @@ -4785,7 +5152,7 @@ recheck: /* * Allow unprivileged RT tasks to decrease priority: */ - if (!capable(CAP_SYS_NICE)) { + if (user && !capable(CAP_SYS_NICE)) { if (rt_policy(policy)) { unsigned long rlim_rtprio; @@ -4816,18 +5183,22 @@ recheck: return -EPERM; } + if (user) { #ifdef CONFIG_RT_GROUP_SCHED - /* - * Do not allow realtime tasks into groups that have no runtime - * assigned. - */ - if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0) - return -EPERM; + /* + * Do not allow realtime tasks into groups that have no runtime + * assigned. + */ + if (rt_bandwidth_enabled() && rt_policy(policy) && + task_group(p)->rt_bandwidth.rt_runtime == 0) + return -EPERM; #endif - retval = security_task_setscheduler(p, policy, param); - if (retval) - return retval; + retval = security_task_setscheduler(p, policy, param); + if (retval) + return retval; + } + /* * make sure no PI-waiters arrive (or leave) while we are * changing the priority of the task: @@ -4870,8 +5241,39 @@ recheck: return 0; } + +/** + * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. + * @p: the task in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + * + * NOTE that the task may be already dead. + */ +int sched_setscheduler(struct task_struct *p, int policy, + struct sched_param *param) +{ + return __sched_setscheduler(p, policy, param, true); +} EXPORT_SYMBOL_GPL(sched_setscheduler); +/** + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. + * @p: the task in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + * + * Just like sched_setscheduler, only don't bother checking if the + * current context has permission. For example, this is needed in + * stop_machine(): we create temporary high priority worker threads, + * but our caller might not have that capability. + */ +int sched_setscheduler_nocheck(struct task_struct *p, int policy, + struct sched_param *param) +{ + return __sched_setscheduler(p, policy, param, false); +} + static int do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) { @@ -5070,24 +5472,6 @@ asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len, return sched_setaffinity(pid, &new_mask); } -/* - * Represents all cpu's present in the system - * In systems capable of hotplug, this map could dynamically grow - * as new cpu's are detected in the system via any platform specific - * method, such as ACPI for e.g. - */ - -cpumask_t cpu_present_map __read_mostly; -EXPORT_SYMBOL(cpu_present_map); - -#ifndef CONFIG_SMP -cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL; -EXPORT_SYMBOL(cpu_online_map); - -cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; -EXPORT_SYMBOL(cpu_possible_map); -#endif - long sched_getaffinity(pid_t pid, cpumask_t *mask) { struct task_struct *p; @@ -5384,7 +5768,7 @@ out_unlock: return retval; } -static const char stat_nam[] = "RSDTtZX"; +static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; void sched_show_task(struct task_struct *p) { @@ -5525,6 +5909,8 @@ static inline void sched_init_granularity(void) sysctl_sched_latency = limit; sysctl_sched_wakeup_granularity *= factor; + + sysctl_sched_shares_ratelimit *= factor; } #ifdef CONFIG_SMP @@ -5566,6 +5952,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask) goto out; } + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && + !cpus_equal(p->cpus_allowed, *new_mask))) { + ret = -EINVAL; + goto out; + } + if (p->sched_class->set_cpus_allowed) p->sched_class->set_cpus_allowed(p, new_mask); else { @@ -5608,7 +6000,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) struct rq *rq_dest, *rq_src; int ret = 0, on_rq; - if (unlikely(cpu_is_offline(dest_cpu))) + if (unlikely(!cpu_active(dest_cpu))) return ret; rq_src = cpu_rq(src_cpu); @@ -5617,10 +6009,10 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) double_rq_lock(rq_src, rq_dest); /* Already moved. */ if (task_cpu(p) != src_cpu) - goto out; + goto done; /* Affinity changed (again). */ if (!cpu_isset(dest_cpu, p->cpus_allowed)) - goto out; + goto fail; on_rq = p->se.on_rq; if (on_rq) @@ -5629,10 +6021,11 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) set_task_cpu(p, dest_cpu); if (on_rq) { activate_task(rq_dest, p, 0); - check_preempt_curr(rq_dest, p); + check_preempt_curr(rq_dest, p, 0); } +done: ret = 1; -out: +fail: double_rq_unlock(rq_src, rq_dest); return ret; } @@ -5882,6 +6275,7 @@ static void migrate_dead_tasks(unsigned int dead_cpu) next = pick_next_task(rq, rq->curr); if (!next) break; + next->sched_class->put_prev_task(rq, next); migrate_dead(dead_cpu, next); } @@ -5952,7 +6346,7 @@ set_table_entry(struct ctl_table *entry, static struct ctl_table * sd_alloc_ctl_domain_table(struct sched_domain *sd) { - struct ctl_table *table = sd_alloc_ctl_entry(12); + struct ctl_table *table = sd_alloc_ctl_entry(13); if (table == NULL) return NULL; @@ -5980,7 +6374,9 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd) sizeof(int), 0644, proc_dointvec_minmax); set_table_entry(&table[10], "flags", &sd->flags, sizeof(int), 0644, proc_dointvec_minmax); - /* &table[11] is terminator */ + set_table_entry(&table[11], "name", sd->name, + CORENAME_MAX_SIZE, 0444, proc_dostring); + /* &table[12] is terminator */ return table; } @@ -6053,6 +6449,36 @@ static void unregister_sched_domain_sysctl(void) } #endif +static void set_rq_online(struct rq *rq) +{ + if (!rq->online) { + const struct sched_class *class; + + cpu_set(rq->cpu, rq->rd->online); + rq->online = 1; + + for_each_class(class) { + if (class->rq_online) + class->rq_online(rq); + } + } +} + +static void set_rq_offline(struct rq *rq) +{ + if (rq->online) { + const struct sched_class *class; + + for_each_class(class) { + if (class->rq_offline) + class->rq_offline(rq); + } + + cpu_clear(rq->cpu, rq->rd->online); + rq->online = 0; + } +} + /* * migration_call - callback that gets triggered when a CPU is added. * Here we can start up the necessary migration thread for the new CPU. @@ -6090,7 +6516,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { BUG_ON(!cpu_isset(cpu, rq->rd->span)); - cpu_set(cpu, rq->rd->online); + + set_rq_online(rq); } spin_unlock_irqrestore(&rq->lock, flags); break; @@ -6151,7 +6578,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { BUG_ON(!cpu_isset(cpu, rq->rd->span)); - cpu_clear(cpu, rq->rd->online); + set_rq_offline(rq); } spin_unlock_irqrestore(&rq->lock, flags); break; @@ -6168,7 +6595,7 @@ static struct notifier_block __cpuinitdata migration_notifier = { .priority = 10 }; -void __init migration_init(void) +static int __init migration_init(void) { void *cpu = (void *)(long)smp_processor_id(); int err; @@ -6178,13 +6605,38 @@ void __init migration_init(void) BUG_ON(err == NOTIFY_BAD); migration_call(&migration_notifier, CPU_ONLINE, cpu); register_cpu_notifier(&migration_notifier); + + return err; } +early_initcall(migration_init); #endif #ifdef CONFIG_SMP #ifdef CONFIG_SCHED_DEBUG +static inline const char *sd_level_to_string(enum sched_domain_level lvl) +{ + switch (lvl) { + case SD_LV_NONE: + return "NONE"; + case SD_LV_SIBLING: + return "SIBLING"; + case SD_LV_MC: + return "MC"; + case SD_LV_CPU: + return "CPU"; + case SD_LV_NODE: + return "NODE"; + case SD_LV_ALLNODES: + return "ALLNODES"; + case SD_LV_MAX: + return "MAX"; + + } + return "MAX"; +} + static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, cpumask_t *groupmask) { @@ -6204,7 +6656,8 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, return -1; } - printk(KERN_CONT "span %s\n", str); + printk(KERN_CONT "span %s level %s\n", + str, sd_level_to_string(sd->level)); if (!cpu_isset(cpu, sd->span)) { printk(KERN_ERR "ERROR: domain->span does not contain " @@ -6288,9 +6741,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu) } kfree(groupmask); } -#else +#else /* !CONFIG_SCHED_DEBUG */ # define sched_domain_debug(sd, cpu) do { } while (0) -#endif +#endif /* CONFIG_SCHED_DEBUG */ static int sd_degenerate(struct sched_domain *sd) { @@ -6350,20 +6803,16 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) static void rq_attach_root(struct rq *rq, struct root_domain *rd) { unsigned long flags; - const struct sched_class *class; spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { struct root_domain *old_rd = rq->rd; - for (class = sched_class_highest; class; class = class->next) { - if (class->leave_domain) - class->leave_domain(rq); - } + if (cpu_isset(rq->cpu, old_rd->online)) + set_rq_offline(rq); cpu_clear(rq->cpu, old_rd->span); - cpu_clear(rq->cpu, old_rd->online); if (atomic_dec_and_test(&old_rd->refcount)) kfree(old_rd); @@ -6374,12 +6823,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd) cpu_set(rq->cpu, rd->span); if (cpu_isset(rq->cpu, cpu_online_map)) - cpu_set(rq->cpu, rd->online); - - for (class = sched_class_highest; class; class = class->next) { - if (class->join_domain) - class->join_domain(rq); - } + set_rq_online(rq); spin_unlock_irqrestore(&rq->lock, flags); } @@ -6390,6 +6834,8 @@ static void init_rootdomain(struct root_domain *rd) cpus_clear(rd->span); cpus_clear(rd->online); + + cpupri_init(&rd->cpupri); } static void init_defrootdomain(void) @@ -6451,7 +6897,8 @@ static cpumask_t cpu_isolated_map = CPU_MASK_NONE; /* Setup the mask of cpus configured for isolated domains */ static int __init isolated_cpu_setup(char *str) { - int ints[NR_CPUS], i; + static int __initdata ints[NR_CPUS]; + int i; str = get_options(str, ARRAY_SIZE(ints), ints); cpus_clear(cpu_isolated_map); @@ -6485,7 +6932,7 @@ init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map, cpus_clear(*covered); - for_each_cpu_mask(i, *span) { + for_each_cpu_mask_nr(i, *span) { struct sched_group *sg; int group = group_fn(i, cpu_map, &sg, tmpmask); int j; @@ -6496,7 +6943,7 @@ init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map, cpus_clear(sg->cpumask); sg->__cpu_power = 0; - for_each_cpu_mask(j, *span) { + for_each_cpu_mask_nr(j, *span) { if (group_fn(j, cpu_map, NULL, tmpmask) != group) continue; @@ -6532,9 +6979,9 @@ static int find_next_best_node(int node, nodemask_t *used_nodes) min_val = INT_MAX; - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { /* Start at @node */ - n = (node + i) % MAX_NUMNODES; + n = (node + i) % nr_node_ids; if (!nr_cpus_node(n)) continue; @@ -6584,7 +7031,7 @@ static void sched_domain_node_span(int node, cpumask_t *span) cpus_or(*span, *span, *nodemask); } } -#endif +#endif /* CONFIG_NUMA */ int sched_smt_power_savings = 0, sched_mc_power_savings = 0; @@ -6603,7 +7050,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, *sg = &per_cpu(sched_group_cpus, cpu); return cpu; } -#endif +#endif /* CONFIG_SCHED_SMT */ /* * multi-core sched-domains: @@ -6611,7 +7058,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, #ifdef CONFIG_SCHED_MC static DEFINE_PER_CPU(struct sched_domain, core_domains); static DEFINE_PER_CPU(struct sched_group, sched_group_core); -#endif +#endif /* CONFIG_SCHED_MC */ #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) static int @@ -6696,7 +7143,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head) if (!sg) return; do { - for_each_cpu_mask(j, sg->cpumask) { + for_each_cpu_mask_nr(j, sg->cpumask) { struct sched_domain *sd; sd = &per_cpu(phys_domains, j); @@ -6713,7 +7160,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head) sg = sg->next; } while (sg != group_head); } -#endif +#endif /* CONFIG_NUMA */ #ifdef CONFIG_NUMA /* Free memory allocated for various sched_group structures */ @@ -6721,14 +7168,14 @@ static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) { int cpu, i; - for_each_cpu_mask(cpu, *cpu_map) { + for_each_cpu_mask_nr(cpu, *cpu_map) { struct sched_group **sched_group_nodes = sched_group_nodes_bycpu[cpu]; if (!sched_group_nodes) continue; - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { struct sched_group *oldsg, *sg = sched_group_nodes[i]; *nodemask = node_to_cpumask(i); @@ -6750,11 +7197,11 @@ next_sg: sched_group_nodes_bycpu[cpu] = NULL; } } -#else +#else /* !CONFIG_NUMA */ static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) { } -#endif +#endif /* CONFIG_NUMA */ /* * Initialize sched groups cpu_power. @@ -6813,13 +7260,21 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) * Non-inlined to reduce accumulated stack pressure in build_sched_domains() */ +#ifdef CONFIG_SCHED_DEBUG +# define SD_INIT_NAME(sd, type) sd->name = #type +#else +# define SD_INIT_NAME(sd, type) do { } while (0) +#endif + #define SD_INIT(sd, type) sd_init_##type(sd) + #define SD_INIT_FUNC(type) \ static noinline void sd_init_##type(struct sched_domain *sd) \ { \ memset(sd, 0, sizeof(*sd)); \ *sd = SD_##type##_INIT; \ sd->level = SD_LV_##type; \ + SD_INIT_NAME(sd, type); \ } SD_INIT_FUNC(CPU) @@ -6921,7 +7376,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* * Allocate the per-node list of sched groups */ - sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *), + sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), GFP_KERNEL); if (!sched_group_nodes) { printk(KERN_WARNING "Can not alloc sched group node list\n"); @@ -6960,7 +7415,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* * Set up domains for cpus specified by the cpu_map. */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = NULL, *p; SCHED_CPUMASK_VAR(nodemask, allmasks); @@ -7027,7 +7482,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #ifdef CONFIG_SCHED_SMT /* Set up CPU (sibling) groups */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { SCHED_CPUMASK_VAR(this_sibling_map, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7044,7 +7499,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #ifdef CONFIG_SCHED_MC /* Set up multi-core groups */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { SCHED_CPUMASK_VAR(this_core_map, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7060,7 +7515,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #endif /* Set up physical groups */ - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { SCHED_CPUMASK_VAR(nodemask, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7084,7 +7539,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, send_covered, tmpmask); } - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { /* Set up node groups */ struct sched_group *sg, *prev; SCHED_CPUMASK_VAR(nodemask, allmasks); @@ -7111,7 +7566,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, goto error; } sched_group_nodes[i] = sg; - for_each_cpu_mask(j, *nodemask) { + for_each_cpu_mask_nr(j, *nodemask) { struct sched_domain *sd; sd = &per_cpu(node_domains, j); @@ -7123,9 +7578,9 @@ static int __build_sched_domains(const cpumask_t *cpu_map, cpus_or(*covered, *covered, *nodemask); prev = sg; - for (j = 0; j < MAX_NUMNODES; j++) { + for (j = 0; j < nr_node_ids; j++) { SCHED_CPUMASK_VAR(notcovered, allmasks); - int n = (i + j) % MAX_NUMNODES; + int n = (i + j) % nr_node_ids; node_to_cpumask_ptr(pnodemask, n); cpus_complement(*notcovered, *covered); @@ -7157,28 +7612,28 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* Calculate CPU power for physical packages and nodes */ #ifdef CONFIG_SCHED_SMT - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(cpu_domains, i); init_sched_groups_power(i, sd); } #endif #ifdef CONFIG_SCHED_MC - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(core_domains, i); init_sched_groups_power(i, sd); } #endif - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(phys_domains, i); init_sched_groups_power(i, sd); } #ifdef CONFIG_NUMA - for (i = 0; i < MAX_NUMNODES; i++) + for (i = 0; i < nr_node_ids; i++) init_numa_sched_groups_power(sched_group_nodes[i]); if (sd_allnodes) { @@ -7191,7 +7646,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #endif /* Attach the domains */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd; #ifdef CONFIG_SCHED_SMT sd = &per_cpu(cpu_domains, i); @@ -7236,18 +7691,6 @@ void __attribute__((weak)) arch_update_cpu_topology(void) } /* - * Free current domain masks. - * Called after all cpus are attached to NULL domain. - */ -static void free_sched_domains(void) -{ - ndoms_cur = 0; - if (doms_cur != &fallback_doms) - kfree(doms_cur); - doms_cur = &fallback_doms; -} - -/* * Set up scheduler domains and groups. Callers must hold the hotplug lock. * For now this just excludes isolated cpus, but could be used to * exclude other special cases in the future. @@ -7286,7 +7729,7 @@ static void detach_destroy_domains(const cpumask_t *cpu_map) unregister_sched_domain_sysctl(); - for_each_cpu_mask(i, *cpu_map) + for_each_cpu_mask_nr(i, *cpu_map) cpu_attach_domain(NULL, &def_root_domain, i); synchronize_sched(); arch_destroy_sched_domains(cpu_map, &tmpmask); @@ -7325,30 +7768,29 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, * ownership of it and will kfree it when done with it. If the caller * failed the kmalloc call, then it can pass in doms_new == NULL, * and partition_sched_domains() will fallback to the single partition - * 'fallback_doms'. + * 'fallback_doms', it also forces the domains to be rebuilt. + * + * If doms_new==NULL it will be replaced with cpu_online_map. + * ndoms_new==0 is a special case for destroying existing domains. + * It will not create the default domain. * * Call with hotplug lock held */ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new, struct sched_domain_attr *dattr_new) { - int i, j; + int i, j, n; mutex_lock(&sched_domains_mutex); /* always unregister in case we don't destroy any domains */ unregister_sched_domain_sysctl(); - if (doms_new == NULL) { - ndoms_new = 1; - doms_new = &fallback_doms; - cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map); - dattr_new = NULL; - } + n = doms_new ? ndoms_new : 0; /* Destroy deleted domains */ for (i = 0; i < ndoms_cur; i++) { - for (j = 0; j < ndoms_new; j++) { + for (j = 0; j < n; j++) { if (cpus_equal(doms_cur[i], doms_new[j]) && dattrs_equal(dattr_cur, i, dattr_new, j)) goto match1; @@ -7359,6 +7801,13 @@ match1: ; } + if (doms_new == NULL) { + ndoms_cur = 0; + doms_new = &fallback_doms; + cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map); + dattr_new = NULL; + } + /* Build new domains */ for (i = 0; i < ndoms_new; i++) { for (j = 0; j < ndoms_cur; j++) { @@ -7389,17 +7838,15 @@ match2: #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) int arch_reinit_sched_domains(void) { - int err; - get_online_cpus(); - mutex_lock(&sched_domains_mutex); - detach_destroy_domains(&cpu_online_map); - free_sched_domains(); - err = arch_init_sched_domains(&cpu_online_map); - mutex_unlock(&sched_domains_mutex); + + /* Destroy domains first to force the rebuild */ + partition_sched_domains(0, NULL, NULL); + + rebuild_sched_domains(); put_online_cpus(); - return err; + return 0; } static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) @@ -7420,30 +7867,34 @@ static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) } #ifdef CONFIG_SCHED_MC -static ssize_t sched_mc_power_savings_show(struct sys_device *dev, char *page) +static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, + char *page) { return sprintf(page, "%u\n", sched_mc_power_savings); } -static ssize_t sched_mc_power_savings_store(struct sys_device *dev, +static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, const char *buf, size_t count) { return sched_power_savings_store(buf, count, 0); } -static SYSDEV_ATTR(sched_mc_power_savings, 0644, sched_mc_power_savings_show, - sched_mc_power_savings_store); +static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, + sched_mc_power_savings_show, + sched_mc_power_savings_store); #endif #ifdef CONFIG_SCHED_SMT -static ssize_t sched_smt_power_savings_show(struct sys_device *dev, char *page) +static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, + char *page) { return sprintf(page, "%u\n", sched_smt_power_savings); } -static ssize_t sched_smt_power_savings_store(struct sys_device *dev, +static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, const char *buf, size_t count) { return sched_power_savings_store(buf, count, 1); } -static SYSDEV_ATTR(sched_smt_power_savings, 0644, sched_smt_power_savings_show, +static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, + sched_smt_power_savings_show, sched_smt_power_savings_store); #endif @@ -7463,54 +7914,51 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) #endif return err; } -#endif +#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ +#ifndef CONFIG_CPUSETS /* - * Force a reinitialization of the sched domains hierarchy. The domains - * and groups cannot be updated in place without racing with the balancing - * code, so we temporarily attach all running cpus to the NULL domain - * which will prevent rebalancing while the sched domains are recalculated. + * Add online and remove offline CPUs from the scheduler domains. + * When cpusets are enabled they take over this function. */ static int update_sched_domains(struct notifier_block *nfb, unsigned long action, void *hcpu) { switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + case CPU_DEAD: + case CPU_DEAD_FROZEN: + partition_sched_domains(1, NULL, NULL); + return NOTIFY_OK; + + default: + return NOTIFY_DONE; + } +} +#endif + +static int update_runtime(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + int cpu = (int)(long)hcpu; + + switch (action) { case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: - detach_destroy_domains(&cpu_online_map); - free_sched_domains(); + disable_runtime(cpu_rq(cpu)); return NOTIFY_OK; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: case CPU_ONLINE: case CPU_ONLINE_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - /* - * Fall through and re-initialise the domains. - */ - break; + enable_runtime(cpu_rq(cpu)); + return NOTIFY_OK; + default: return NOTIFY_DONE; } - -#ifndef CONFIG_CPUSETS - /* - * Create default domain partitioning if cpusets are disabled. - * Otherwise we let cpusets rebuild the domains based on the - * current setup. - */ - - /* The hotplug lock is already held by cpu_up/cpu_down */ - arch_init_sched_domains(&cpu_online_map); -#endif - - return NOTIFY_OK; } void __init sched_init_smp(void) @@ -7530,8 +7978,15 @@ void __init sched_init_smp(void) cpu_set(smp_processor_id(), non_isolated_cpus); mutex_unlock(&sched_domains_mutex); put_online_cpus(); + +#ifndef CONFIG_CPUSETS /* XXX: Theoretical race here - CPU may be hotplugged now */ hotcpu_notifier(update_sched_domains, 0); +#endif + + /* RT runtime code needs to handle some hotplug events */ + hotcpu_notifier(update_runtime, 0); + init_hrtick(); /* Move init over to a non-isolated CPU */ @@ -7688,8 +8143,8 @@ void __init sched_init(void) root_task_group.cfs_rq = (struct cfs_rq **)ptr; ptr += nr_cpu_ids * sizeof(void **); -#endif -#endif +#endif /* CONFIG_USER_SCHED */ +#endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED init_task_group.rt_se = (struct sched_rt_entity **)ptr; ptr += nr_cpu_ids * sizeof(void **); @@ -7703,8 +8158,8 @@ void __init sched_init(void) root_task_group.rt_rq = (struct rt_rq **)ptr; ptr += nr_cpu_ids * sizeof(void **); -#endif -#endif +#endif /* CONFIG_USER_SCHED */ +#endif /* CONFIG_RT_GROUP_SCHED */ } #ifdef CONFIG_SMP @@ -7720,8 +8175,8 @@ void __init sched_init(void) #ifdef CONFIG_USER_SCHED init_rt_bandwidth(&root_task_group.rt_bandwidth, global_rt_period(), RUNTIME_INF); -#endif -#endif +#endif /* CONFIG_USER_SCHED */ +#endif /* CONFIG_RT_GROUP_SCHED */ #ifdef CONFIG_GROUP_SCHED list_add(&init_task_group.list, &task_groups); @@ -7731,15 +8186,14 @@ void __init sched_init(void) INIT_LIST_HEAD(&root_task_group.children); init_task_group.parent = &root_task_group; list_add(&init_task_group.siblings, &root_task_group.children); -#endif -#endif +#endif /* CONFIG_USER_SCHED */ +#endif /* CONFIG_GROUP_SCHED */ for_each_possible_cpu(i) { struct rq *rq; rq = cpu_rq(i); spin_lock_init(&rq->lock); - lockdep_set_class(&rq->lock, &rq->rq_lock_key); rq->nr_running = 0; init_cfs_rq(&rq->cfs, rq); init_rt_rq(&rq->rt, rq); @@ -7812,6 +8266,7 @@ void __init sched_init(void) rq->next_balance = jiffies; rq->push_cpu = 0; rq->cpu = i; + rq->online = 0; rq->migration_thread = NULL; INIT_LIST_HEAD(&rq->migration_queue); rq_attach_root(rq, &def_root_domain); @@ -7827,7 +8282,7 @@ void __init sched_init(void) #endif #ifdef CONFIG_SMP - open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); + open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); #endif #ifdef CONFIG_RT_MUTEXES @@ -7861,20 +8316,25 @@ void __might_sleep(char *file, int line) #ifdef in_atomic static unsigned long prev_jiffy; /* ratelimiting */ - if ((in_atomic() || irqs_disabled()) && - system_state == SYSTEM_RUNNING && !oops_in_progress) { - if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) - return; - prev_jiffy = jiffies; - printk(KERN_ERR "BUG: sleeping function called from invalid" - " context at %s:%d\n", file, line); - printk("in_atomic():%d, irqs_disabled():%d\n", - in_atomic(), irqs_disabled()); - debug_show_held_locks(current); - if (irqs_disabled()) - print_irqtrace_events(current); - dump_stack(); - } + if ((!in_atomic() && !irqs_disabled()) || + system_state != SYSTEM_RUNNING || oops_in_progress) + return; + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) + return; + prev_jiffy = jiffies; + + printk(KERN_ERR + "BUG: sleeping function called from invalid context at %s:%d\n", + file, line); + printk(KERN_ERR + "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", + in_atomic(), irqs_disabled(), + current->pid, current->comm); + + debug_show_held_locks(current); + if (irqs_disabled()) + print_irqtrace_events(current); + dump_stack(); #endif } EXPORT_SYMBOL(__might_sleep); @@ -8051,7 +8511,7 @@ static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) { list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); } -#else +#else /* !CONFG_FAIR_GROUP_SCHED */ static inline void free_fair_sched_group(struct task_group *tg) { } @@ -8069,7 +8529,7 @@ static inline void register_fair_sched_group(struct task_group *tg, int cpu) static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) { } -#endif +#endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED static void free_rt_sched_group(struct task_group *tg) @@ -8140,7 +8600,7 @@ static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) { list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); } -#else +#else /* !CONFIG_RT_GROUP_SCHED */ static inline void free_rt_sched_group(struct task_group *tg) { } @@ -8158,7 +8618,7 @@ static inline void register_rt_sched_group(struct task_group *tg, int cpu) static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) { } -#endif +#endif /* CONFIG_RT_GROUP_SCHED */ #ifdef CONFIG_GROUP_SCHED static void free_sched_group(struct task_group *tg) @@ -8195,8 +8655,8 @@ struct task_group *sched_create_group(struct task_group *parent) WARN_ON(!parent); /* root should already exist */ tg->parent = parent; - list_add_rcu(&tg->siblings, &parent->children); INIT_LIST_HEAD(&tg->children); + list_add_rcu(&tg->siblings, &parent->children); spin_unlock_irqrestore(&task_group_lock, flags); return tg; @@ -8269,17 +8729,14 @@ void sched_move_task(struct task_struct *tsk) task_rq_unlock(rq, &flags); } -#endif +#endif /* CONFIG_GROUP_SCHED */ #ifdef CONFIG_FAIR_GROUP_SCHED -static void set_se_shares(struct sched_entity *se, unsigned long shares) +static void __set_se_shares(struct sched_entity *se, unsigned long shares) { struct cfs_rq *cfs_rq = se->cfs_rq; - struct rq *rq = cfs_rq->rq; int on_rq; - spin_lock_irq(&rq->lock); - on_rq = se->on_rq; if (on_rq) dequeue_entity(cfs_rq, se, 0); @@ -8289,8 +8746,17 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares) if (on_rq) enqueue_entity(cfs_rq, se, 0); +} - spin_unlock_irq(&rq->lock); +static void set_se_shares(struct sched_entity *se, unsigned long shares) +{ + struct cfs_rq *cfs_rq = se->cfs_rq; + struct rq *rq = cfs_rq->rq; + unsigned long flags; + + spin_lock_irqsave(&rq->lock, flags); + __set_se_shares(se, shares); + spin_unlock_irqrestore(&rq->lock, flags); } static DEFINE_MUTEX(shares_mutex); @@ -8329,8 +8795,13 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) * w/o tripping rebalance_share or load_balance_fair. */ tg->shares = shares; - for_each_possible_cpu(i) + for_each_possible_cpu(i) { + /* + * force a rebalance + */ + cfs_rq_set_shares(tg->cfs_rq[i], 0); set_se_shares(tg->se[i], shares); + } /* * Enable load balance activity on this group, by inserting it back on @@ -8361,73 +8832,95 @@ static DEFINE_MUTEX(rt_constraints_mutex); static unsigned long to_ratio(u64 period, u64 runtime) { if (runtime == RUNTIME_INF) - return 1ULL << 16; + return 1ULL << 20; - return div64_u64(runtime << 16, period); + return div64_u64(runtime << 20, period); } -#ifdef CONFIG_CGROUP_SCHED -static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) +/* Must be called with tasklist_lock held */ +static inline int tg_has_rt_tasks(struct task_group *tg) { - struct task_group *tgi, *parent = tg ? tg->parent : NULL; - unsigned long total = 0; + struct task_struct *g, *p; - if (!parent) { - if (global_rt_period() < period) - return 0; + do_each_thread(g, p) { + if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) + return 1; + } while_each_thread(g, p); - return to_ratio(period, runtime) < - to_ratio(global_rt_period(), global_rt_runtime()); - } + return 0; +} - if (ktime_to_ns(parent->rt_bandwidth.rt_period) < period) - return 0; +struct rt_schedulable_data { + struct task_group *tg; + u64 rt_period; + u64 rt_runtime; +}; - rcu_read_lock(); - list_for_each_entry_rcu(tgi, &parent->children, siblings) { - if (tgi == tg) - continue; +static int tg_schedulable(struct task_group *tg, void *data) +{ + struct rt_schedulable_data *d = data; + struct task_group *child; + unsigned long total, sum = 0; + u64 period, runtime; + + period = ktime_to_ns(tg->rt_bandwidth.rt_period); + runtime = tg->rt_bandwidth.rt_runtime; - total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period), - tgi->rt_bandwidth.rt_runtime); + if (tg == d->tg) { + period = d->rt_period; + runtime = d->rt_runtime; } - rcu_read_unlock(); - return total + to_ratio(period, runtime) < - to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period), - parent->rt_bandwidth.rt_runtime); -} -#elif defined CONFIG_USER_SCHED -static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) -{ - struct task_group *tgi; - unsigned long total = 0; - unsigned long global_ratio = - to_ratio(global_rt_period(), global_rt_runtime()); + /* + * Cannot have more runtime than the period. + */ + if (runtime > period && runtime != RUNTIME_INF) + return -EINVAL; - rcu_read_lock(); - list_for_each_entry_rcu(tgi, &task_groups, list) { - if (tgi == tg) - continue; + /* + * Ensure we don't starve existing RT tasks. + */ + if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) + return -EBUSY; + + total = to_ratio(period, runtime); - total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period), - tgi->rt_bandwidth.rt_runtime); + /* + * Nobody can have more than the global setting allows. + */ + if (total > to_ratio(global_rt_period(), global_rt_runtime())) + return -EINVAL; + + /* + * The sum of our children's runtime should not exceed our own. + */ + list_for_each_entry_rcu(child, &tg->children, siblings) { + period = ktime_to_ns(child->rt_bandwidth.rt_period); + runtime = child->rt_bandwidth.rt_runtime; + + if (child == d->tg) { + period = d->rt_period; + runtime = d->rt_runtime; + } + + sum += to_ratio(period, runtime); } - rcu_read_unlock(); - return total + to_ratio(period, runtime) < global_ratio; + if (sum > total) + return -EINVAL; + + return 0; } -#endif -/* Must be called with tasklist_lock held */ -static inline int tg_has_rt_tasks(struct task_group *tg) +static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) { - struct task_struct *g, *p; - do_each_thread(g, p) { - if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) - return 1; - } while_each_thread(g, p); - return 0; + struct rt_schedulable_data data = { + .tg = tg, + .rt_period = period, + .rt_runtime = runtime, + }; + + return walk_tg_tree(tg_schedulable, tg_nop, &data); } static int tg_set_bandwidth(struct task_group *tg, @@ -8437,14 +8930,9 @@ static int tg_set_bandwidth(struct task_group *tg, mutex_lock(&rt_constraints_mutex); read_lock(&tasklist_lock); - if (rt_runtime == 0 && tg_has_rt_tasks(tg)) { - err = -EBUSY; + err = __rt_schedulable(tg, rt_period, rt_runtime); + if (err) goto unlock; - } - if (!__rt_schedulable(tg, rt_period, rt_runtime)) { - err = -EINVAL; - goto unlock; - } spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); @@ -8496,6 +8984,9 @@ int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) rt_period = (u64)rt_period_us * NSEC_PER_USEC; rt_runtime = tg->rt_bandwidth.rt_runtime; + if (rt_period == 0) + return -EINVAL; + return tg_set_bandwidth(tg, rt_period, rt_runtime); } @@ -8510,21 +9001,38 @@ long sched_group_rt_period(struct task_group *tg) static int sched_rt_global_constraints(void) { + u64 runtime, period; int ret = 0; + if (sysctl_sched_rt_period <= 0) + return -EINVAL; + + runtime = global_rt_runtime(); + period = global_rt_period(); + + /* + * Sanity check on the sysctl variables. + */ + if (runtime > period && runtime != RUNTIME_INF) + return -EINVAL; + mutex_lock(&rt_constraints_mutex); - if (!__rt_schedulable(NULL, 1, 0)) - ret = -EINVAL; + read_lock(&tasklist_lock); + ret = __rt_schedulable(NULL, 0, 0); + read_unlock(&tasklist_lock); mutex_unlock(&rt_constraints_mutex); return ret; } -#else +#else /* !CONFIG_RT_GROUP_SCHED */ static int sched_rt_global_constraints(void) { unsigned long flags; int i; + if (sysctl_sched_rt_period <= 0) + return -EINVAL; + spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); for_each_possible_cpu(i) { struct rt_rq *rt_rq = &cpu_rq(i)->rt; @@ -8537,7 +9045,7 @@ static int sched_rt_global_constraints(void) return 0; } -#endif +#endif /* CONFIG_RT_GROUP_SCHED */ int sched_rt_handler(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, @@ -8585,7 +9093,6 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) if (!cgrp->parent) { /* This is early initialization for the top cgroup */ - init_task_group.css.cgroup = cgrp; return &init_task_group.css; } @@ -8594,9 +9101,6 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) if (IS_ERR(tg)) return ERR_PTR(-ENOMEM); - /* Bind the cgroup to task_group object we just created */ - tg->css.cgroup = cgrp; - return &tg->css; } @@ -8645,7 +9149,7 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) return (u64) tg->shares; } -#endif +#endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, @@ -8669,7 +9173,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) { return sched_group_rt_period(cgroup_tg(cgrp)); } -#endif +#endif /* CONFIG_RT_GROUP_SCHED */ static struct cftype cpu_files[] = { #ifdef CONFIG_FAIR_GROUP_SCHED diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index ce05271..e8ab096 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -3,25 +3,26 @@ * * Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> * + * Updates and enhancements: + * Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com> + * * Based on code by: * Ingo Molnar <mingo@redhat.com> * Guillaume Chazarain <guichaz@gmail.com> * * Create a semi stable clock from a mixture of other events, including: * - gtod - * - jiffies * - sched_clock() * - explicit idle events * * We use gtod as base and the unstable clock deltas. The deltas are filtered, - * making it monotonic and keeping it within an expected window. This window - * is set up using jiffies. + * making it monotonic and keeping it within an expected window. * * Furthermore, explicit sleep and wakeup hooks allow us to account for time * that is otherwise invisible (TSC gets stopped). * * The clock: sched_clock_cpu() is monotonic per cpu, and should be somewhat - * consistent between cpus (never more than 1 jiffies difference). + * consistent between cpus (never more than 2 jiffies difference). */ #include <linux/sched.h> #include <linux/percpu.h> @@ -29,6 +30,17 @@ #include <linux/ktime.h> #include <linux/module.h> +/* + * Scheduler clock - returns current time in nanosec units. + * This is default implementation. + * Architectures and sub-architectures can override this. + */ +unsigned long long __attribute__((weak)) sched_clock(void) +{ + return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ); +} + +static __read_mostly int sched_clock_running; #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK @@ -40,8 +52,6 @@ struct sched_clock_data { */ raw_spinlock_t lock; - unsigned long prev_jiffies; - u64 prev_raw; u64 tick_raw; u64 tick_gtod; u64 clock; @@ -59,20 +69,15 @@ static inline struct sched_clock_data *cpu_sdc(int cpu) return &per_cpu(sched_clock_data, cpu); } -static __read_mostly int sched_clock_running; - void sched_clock_init(void) { u64 ktime_now = ktime_to_ns(ktime_get()); - unsigned long now_jiffies = jiffies; int cpu; for_each_possible_cpu(cpu) { struct sched_clock_data *scd = cpu_sdc(cpu); scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; - scd->prev_jiffies = now_jiffies; - scd->prev_raw = 0; scd->tick_raw = 0; scd->tick_gtod = ktime_now; scd->clock = ktime_now; @@ -82,45 +87,51 @@ void sched_clock_init(void) } /* + * min,max except they take wrapping into account + */ + +static inline u64 wrap_min(u64 x, u64 y) +{ + return (s64)(x - y) < 0 ? x : y; +} + +static inline u64 wrap_max(u64 x, u64 y) +{ + return (s64)(x - y) > 0 ? x : y; +} + +/* * update the percpu scd from the raw @now value * * - filter out backward motion - * - use jiffies to generate a min,max window to clip the raw values + * - use the GTOD tick value to create a window to filter crazy TSC values */ -static void __update_sched_clock(struct sched_clock_data *scd, u64 now) +static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now) { - unsigned long now_jiffies = jiffies; - long delta_jiffies = now_jiffies - scd->prev_jiffies; - u64 clock = scd->clock; - u64 min_clock, max_clock; - s64 delta = now - scd->prev_raw; + s64 delta = now - scd->tick_raw; + u64 clock, min_clock, max_clock; WARN_ON_ONCE(!irqs_disabled()); - min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC; - if (unlikely(delta < 0)) { - clock++; - goto out; - } + if (unlikely(delta < 0)) + delta = 0; - max_clock = min_clock + TICK_NSEC; + /* + * scd->clock = clamp(scd->tick_gtod + delta, + * max(scd->tick_gtod, scd->clock), + * scd->tick_gtod + TICK_NSEC); + */ - if (unlikely(clock + delta > max_clock)) { - if (clock < max_clock) - clock = max_clock; - else - clock++; - } else { - clock += delta; - } + clock = scd->tick_gtod + delta; + min_clock = wrap_max(scd->tick_gtod, scd->clock); + max_clock = scd->tick_gtod + TICK_NSEC; - out: - if (unlikely(clock < min_clock)) - clock = min_clock; + clock = wrap_max(clock, min_clock); + clock = wrap_min(clock, max_clock); - scd->prev_raw = now; - scd->prev_jiffies = now_jiffies; scd->clock = clock; + + return scd->clock; } static void lock_double_clock(struct sched_clock_data *data1, @@ -138,7 +149,7 @@ static void lock_double_clock(struct sched_clock_data *data1, u64 sched_clock_cpu(int cpu) { struct sched_clock_data *scd = cpu_sdc(cpu); - u64 now, clock; + u64 now, clock, this_clock, remote_clock; if (unlikely(!sched_clock_running)) return 0ull; @@ -147,30 +158,36 @@ u64 sched_clock_cpu(int cpu) now = sched_clock(); if (cpu != raw_smp_processor_id()) { - /* - * in order to update a remote cpu's clock based on our - * unstable raw time rebase it against: - * tick_raw (offset between raw counters) - * tick_gotd (tick offset between cpus) - */ struct sched_clock_data *my_scd = this_scd(); lock_double_clock(scd, my_scd); - now -= my_scd->tick_raw; - now += scd->tick_raw; + this_clock = __update_sched_clock(my_scd, now); + remote_clock = scd->clock; - now -= my_scd->tick_gtod; - now += scd->tick_gtod; + /* + * Use the opportunity that we have both locks + * taken to couple the two clocks: we take the + * larger time as the latest time for both + * runqueues. (this creates monotonic movement) + */ + if (likely((s64)(remote_clock - this_clock) < 0)) { + clock = this_clock; + scd->clock = clock; + } else { + /* + * Should be rare, but possible: + */ + clock = remote_clock; + my_scd->clock = remote_clock; + } __raw_spin_unlock(&my_scd->lock); } else { __raw_spin_lock(&scd->lock); + clock = __update_sched_clock(scd, now); } - __update_sched_clock(scd, now); - clock = scd->clock; - __raw_spin_unlock(&scd->lock); return clock; @@ -186,18 +203,13 @@ void sched_clock_tick(void) WARN_ON_ONCE(!irqs_disabled()); - now = sched_clock(); now_gtod = ktime_to_ns(ktime_get()); + now = sched_clock(); __raw_spin_lock(&scd->lock); - __update_sched_clock(scd, now); - /* - * update tick_gtod after __update_sched_clock() because that will - * already observe 1 new jiffy; adding a new tick_gtod to that would - * increase the clock 2 jiffies. - */ scd->tick_raw = now; scd->tick_gtod = now_gtod; + __update_sched_clock(scd, now); __raw_spin_unlock(&scd->lock); } @@ -215,32 +227,37 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event); */ void sched_clock_idle_wakeup_event(u64 delta_ns) { - struct sched_clock_data *scd = this_scd(); - u64 now = sched_clock(); - - /* - * Override the previous timestamp and ignore all - * sched_clock() deltas that occured while we idled, - * and use the PM-provided delta_ns to advance the - * rq clock: - */ - __raw_spin_lock(&scd->lock); - scd->prev_raw = now; - scd->clock += delta_ns; - __raw_spin_unlock(&scd->lock); - + sched_clock_tick(); touch_softlockup_watchdog(); } EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event); +#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */ + +void sched_clock_init(void) +{ + sched_clock_running = 1; +} + +u64 sched_clock_cpu(int cpu) +{ + if (unlikely(!sched_clock_running)) + return 0; + + return sched_clock(); +} + #endif -/* - * Scheduler clock - returns current time in nanosec units. - * This is default implementation. - * Architectures and sub-architectures can override this. - */ -unsigned long long __attribute__((weak)) sched_clock(void) +unsigned long long cpu_clock(int cpu) { - return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ); + unsigned long long clock; + unsigned long flags; + + local_irq_save(flags); + clock = sched_clock_cpu(cpu); + local_irq_restore(flags); + + return clock; } +EXPORT_SYMBOL_GPL(cpu_clock); diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c new file mode 100644 index 0000000..52154fe --- /dev/null +++ b/kernel/sched_cpupri.c @@ -0,0 +1,174 @@ +/* + * kernel/sched_cpupri.c + * + * CPU priority management + * + * Copyright (C) 2007-2008 Novell + * + * Author: Gregory Haskins <ghaskins@novell.com> + * + * This code tracks the priority of each CPU so that global migration + * decisions are easy to calculate. Each CPU can be in a state as follows: + * + * (INVALID), IDLE, NORMAL, RT1, ... RT99 + * + * going from the lowest priority to the highest. CPUs in the INVALID state + * are not eligible for routing. The system maintains this state with + * a 2 dimensional bitmap (the first for priority class, the second for cpus + * in that class). Therefore a typical application without affinity + * restrictions can find a suitable CPU with O(1) complexity (e.g. two bit + * searches). For tasks with affinity restrictions, the algorithm has a + * worst case complexity of O(min(102, nr_domcpus)), though the scenario that + * yields the worst case search is fairly contrived. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include "sched_cpupri.h" + +/* Convert between a 140 based task->prio, and our 102 based cpupri */ +static int convert_prio(int prio) +{ + int cpupri; + + if (prio == CPUPRI_INVALID) + cpupri = CPUPRI_INVALID; + else if (prio == MAX_PRIO) + cpupri = CPUPRI_IDLE; + else if (prio >= MAX_RT_PRIO) + cpupri = CPUPRI_NORMAL; + else + cpupri = MAX_RT_PRIO - prio + 1; + + return cpupri; +} + +#define for_each_cpupri_active(array, idx) \ + for (idx = find_first_bit(array, CPUPRI_NR_PRIORITIES); \ + idx < CPUPRI_NR_PRIORITIES; \ + idx = find_next_bit(array, CPUPRI_NR_PRIORITIES, idx+1)) + +/** + * cpupri_find - find the best (lowest-pri) CPU in the system + * @cp: The cpupri context + * @p: The task + * @lowest_mask: A mask to fill in with selected CPUs + * + * Note: This function returns the recommended CPUs as calculated during the + * current invokation. By the time the call returns, the CPUs may have in + * fact changed priorities any number of times. While not ideal, it is not + * an issue of correctness since the normal rebalancer logic will correct + * any discrepancies created by racing against the uncertainty of the current + * priority configuration. + * + * Returns: (int)bool - CPUs were found + */ +int cpupri_find(struct cpupri *cp, struct task_struct *p, + cpumask_t *lowest_mask) +{ + int idx = 0; + int task_pri = convert_prio(p->prio); + + for_each_cpupri_active(cp->pri_active, idx) { + struct cpupri_vec *vec = &cp->pri_to_cpu[idx]; + cpumask_t mask; + + if (idx >= task_pri) + break; + + cpus_and(mask, p->cpus_allowed, vec->mask); + + if (cpus_empty(mask)) + continue; + + *lowest_mask = mask; + return 1; + } + + return 0; +} + +/** + * cpupri_set - update the cpu priority setting + * @cp: The cpupri context + * @cpu: The target cpu + * @pri: The priority (INVALID-RT99) to assign to this CPU + * + * Note: Assumes cpu_rq(cpu)->lock is locked + * + * Returns: (void) + */ +void cpupri_set(struct cpupri *cp, int cpu, int newpri) +{ + int *currpri = &cp->cpu_to_pri[cpu]; + int oldpri = *currpri; + unsigned long flags; + + newpri = convert_prio(newpri); + + BUG_ON(newpri >= CPUPRI_NR_PRIORITIES); + + if (newpri == oldpri) + return; + + /* + * If the cpu was currently mapped to a different value, we + * first need to unmap the old value + */ + if (likely(oldpri != CPUPRI_INVALID)) { + struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri]; + + spin_lock_irqsave(&vec->lock, flags); + + vec->count--; + if (!vec->count) + clear_bit(oldpri, cp->pri_active); + cpu_clear(cpu, vec->mask); + + spin_unlock_irqrestore(&vec->lock, flags); + } + + if (likely(newpri != CPUPRI_INVALID)) { + struct cpupri_vec *vec = &cp->pri_to_cpu[newpri]; + + spin_lock_irqsave(&vec->lock, flags); + + cpu_set(cpu, vec->mask); + vec->count++; + if (vec->count == 1) + set_bit(newpri, cp->pri_active); + + spin_unlock_irqrestore(&vec->lock, flags); + } + + *currpri = newpri; +} + +/** + * cpupri_init - initialize the cpupri structure + * @cp: The cpupri context + * + * Returns: (void) + */ +void cpupri_init(struct cpupri *cp) +{ + int i; + + memset(cp, 0, sizeof(*cp)); + + for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) { + struct cpupri_vec *vec = &cp->pri_to_cpu[i]; + + spin_lock_init(&vec->lock); + vec->count = 0; + cpus_clear(vec->mask); + } + + for_each_possible_cpu(i) + cp->cpu_to_pri[i] = CPUPRI_INVALID; +} + + diff --git a/kernel/sched_cpupri.h b/kernel/sched_cpupri.h new file mode 100644 index 0000000..f25811b0 --- /dev/null +++ b/kernel/sched_cpupri.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_CPUPRI_H +#define _LINUX_CPUPRI_H + +#include <linux/sched.h> + +#define CPUPRI_NR_PRIORITIES (MAX_RT_PRIO + 2) +#define CPUPRI_NR_PRI_WORDS BITS_TO_LONGS(CPUPRI_NR_PRIORITIES) + +#define CPUPRI_INVALID -1 +#define CPUPRI_IDLE 0 +#define CPUPRI_NORMAL 1 +/* values 2-101 are RT priorities 0-99 */ + +struct cpupri_vec { + spinlock_t lock; + int count; + cpumask_t mask; +}; + +struct cpupri { + struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES]; + long pri_active[CPUPRI_NR_PRI_WORDS]; + int cpu_to_pri[NR_CPUS]; +}; + +#ifdef CONFIG_SMP +int cpupri_find(struct cpupri *cp, + struct task_struct *p, cpumask_t *lowest_mask); +void cpupri_set(struct cpupri *cp, int cpu, int pri); +void cpupri_init(struct cpupri *cp); +#else +#define cpupri_set(cp, cpu, pri) do { } while (0) +#define cpupri_init() do { } while (0) +#endif + +#endif /* _LINUX_CPUPRI_H */ diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 8bb7130..ad958c1 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -119,9 +119,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) struct sched_entity *last; unsigned long flags; -#if !defined(CONFIG_CGROUP_SCHED) || !defined(CONFIG_USER_SCHED) - SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu); -#else +#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED) char path[128] = ""; struct cgroup *cgroup = NULL; struct task_group *tg = cfs_rq->tg; @@ -133,6 +131,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) cgroup_path(cgroup, path, sizeof(path)); SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path); +#else + SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu); #endif SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock", @@ -162,11 +162,64 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running); SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); #ifdef CONFIG_SCHEDSTATS - SEQ_printf(m, " .%-30s: %d\n", "bkl_count", - rq->bkl_count); +#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n); + + P(yld_exp_empty); + P(yld_act_empty); + P(yld_both_empty); + P(yld_count); + + P(sched_switch); + P(sched_count); + P(sched_goidle); + + P(ttwu_count); + P(ttwu_local); + + P(bkl_count); + +#undef P #endif SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over", cfs_rq->nr_spread_over); +#ifdef CONFIG_FAIR_GROUP_SCHED +#ifdef CONFIG_SMP + SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares); +#endif +#endif +} + +void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq) +{ +#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED) + char path[128] = ""; + struct cgroup *cgroup = NULL; + struct task_group *tg = rt_rq->tg; + + if (tg) + cgroup = tg->css.cgroup; + + if (cgroup) + cgroup_path(cgroup, path, sizeof(path)); + + SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path); +#else + SEQ_printf(m, "\nrt_rq[%d]:\n", cpu); +#endif + + +#define P(x) \ + SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x)) +#define PN(x) \ + SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x)) + + P(rt_nr_running); + P(rt_throttled); + PN(rt_time); + PN(rt_runtime); + +#undef PN +#undef P } static void print_cpu(struct seq_file *m, int cpu) @@ -208,6 +261,7 @@ static void print_cpu(struct seq_file *m, int cpu) #undef PN print_cfs_stats(m, cpu); + print_rt_stats(m, cpu); print_rq(m, rq, cpu); } @@ -279,12 +333,10 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) unsigned long flags; int num_threads = 1; - rcu_read_lock(); if (lock_task_sighand(p, &flags)) { num_threads = atomic_read(&p->signal->count); unlock_task_sighand(p, &flags); } - rcu_read_unlock(); SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads); SEQ_printf(m, diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 08ae848..18fd171 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -63,13 +63,13 @@ unsigned int __read_mostly sysctl_sched_compat_yield; /* * SCHED_OTHER wake-up granularity. - * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -unsigned int sysctl_sched_wakeup_granularity = 10000000UL; +unsigned int sysctl_sched_wakeup_granularity = 5000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; @@ -334,6 +334,34 @@ int sched_nr_latency_handler(struct ctl_table *table, int write, #endif /* + * delta *= w / rw + */ +static inline unsigned long +calc_delta_weight(unsigned long delta, struct sched_entity *se) +{ + for_each_sched_entity(se) { + delta = calc_delta_mine(delta, + se->load.weight, &cfs_rq_of(se)->load); + } + + return delta; +} + +/* + * delta *= rw / w + */ +static inline unsigned long +calc_delta_fair(unsigned long delta, struct sched_entity *se) +{ + for_each_sched_entity(se) { + delta = calc_delta_mine(delta, + cfs_rq_of(se)->load.weight, &se->load); + } + + return delta; +} + +/* * The idea is to set a period in which each task runs once. * * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch @@ -362,47 +390,22 @@ static u64 __sched_period(unsigned long nr_running) */ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se) { - u64 slice = __sched_period(cfs_rq->nr_running); - - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - - slice *= se->load.weight; - do_div(slice, cfs_rq->load.weight); - } - - - return slice; + return calc_delta_weight(__sched_period(cfs_rq->nr_running), se); } /* * We calculate the vruntime slice of a to be inserted task * - * vs = s/w = p/rw + * vs = s*rw/w = p */ static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se) { unsigned long nr_running = cfs_rq->nr_running; - unsigned long weight; - u64 vslice; if (!se->on_rq) nr_running++; - vslice = __sched_period(nr_running); - - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - - weight = cfs_rq->load.weight; - if (!se->on_rq) - weight += se->load.weight; - - vslice *= NICE_0_LOAD; - do_div(vslice, weight); - } - - return vslice; + return __sched_period(nr_running); } /* @@ -419,11 +422,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, curr->sum_exec_runtime += delta_exec; schedstat_add(cfs_rq, exec_clock, delta_exec); - delta_exec_weighted = delta_exec; - if (unlikely(curr->load.weight != NICE_0_LOAD)) { - delta_exec_weighted = calc_delta_fair(delta_exec_weighted, - &curr->load); - } + delta_exec_weighted = calc_delta_fair(delta_exec, curr); curr->vruntime += delta_exec_weighted; } @@ -510,22 +509,45 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) * Scheduling class queueing methods: */ +#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED +static void +add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) +{ + cfs_rq->task_weight += weight; +} +#else +static inline void +add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) +{ +} +#endif + static void account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { update_load_add(&cfs_rq->load, se->load.weight); + if (!parent_entity(se)) + inc_cpu_load(rq_of(cfs_rq), se->load.weight); + if (entity_is_task(se)) { + add_cfs_task_weight(cfs_rq, se->load.weight); + list_add(&se->group_node, &cfs_rq->tasks); + } cfs_rq->nr_running++; se->on_rq = 1; - list_add(&se->group_node, &cfs_rq->tasks); } static void account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) { update_load_sub(&cfs_rq->load, se->load.weight); + if (!parent_entity(se)) + dec_cpu_load(rq_of(cfs_rq), se->load.weight); + if (entity_is_task(se)) { + add_cfs_task_weight(cfs_rq, -se->load.weight); + list_del_init(&se->group_node); + } cfs_rq->nr_running--; se->on_rq = 0; - list_del_init(&se->group_node); } static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) @@ -609,8 +631,17 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (!initial) { /* sleeps upto a single latency don't count. */ - if (sched_feat(NEW_FAIR_SLEEPERS)) - vruntime -= sysctl_sched_latency; + if (sched_feat(NEW_FAIR_SLEEPERS)) { + unsigned long thresh = sysctl_sched_latency; + + /* + * convert the sleeper threshold into virtual time + */ + if (sched_feat(NORMALIZED_SLEEPER)) + thresh = calc_delta_fair(thresh, se); + + vruntime -= thresh; + } /* ensure we never gain time by being placed backwards. */ vruntime = max_vruntime(se->vruntime, vruntime); @@ -639,21 +670,6 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) __enqueue_entity(cfs_rq, se); } -static void update_avg(u64 *avg, u64 sample) -{ - s64 diff = sample - *avg; - *avg += diff >> 3; -} - -static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se) -{ - if (!se->last_wakeup) - return; - - update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup); - se->last_wakeup = 0; -} - static void dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) { @@ -664,7 +680,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) update_stats_dequeue(cfs_rq, se); if (sleep) { - update_avg_stats(cfs_rq, se); #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { struct task_struct *tsk = task_of(se); @@ -726,17 +741,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) se->prev_sum_exec_runtime = se->sum_exec_runtime; } -static int -wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); - static struct sched_entity * pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (!cfs_rq->next) - return se; + struct rq *rq = rq_of(cfs_rq); + u64 pair_slice = rq->clock - cfs_rq->pair_start; - if (wakeup_preempt_entity(cfs_rq->next, se) != 0) + if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) { + cfs_rq->pair_start = rq->clock; return se; + } return cfs_rq->next; } @@ -808,7 +822,6 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) #ifdef CONFIG_SCHED_HRTICK static void hrtick_start_fair(struct rq *rq, struct task_struct *p) { - int requeue = rq->curr == p; struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); @@ -829,13 +842,13 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p) * Don't schedule slices shorter than 10000ns, that just * doesn't make sense. Rely on vruntime for fairness. */ - if (!requeue) - delta = max(10000LL, delta); + if (rq->curr != p) + delta = max_t(s64, 10000LL, delta); - hrtick_start(rq, delta, requeue); + hrtick_start(rq, delta); } } -#else +#else /* !CONFIG_SCHED_HRTICK */ static inline void hrtick_start_fair(struct rq *rq, struct task_struct *p) { @@ -934,6 +947,8 @@ static void yield_task_fair(struct rq *rq) * not idle and an idle cpu is available. The span of cpus to * search starts with cpus closest then further out as needed, * so we always favor a closer, idle cpu. + * Domains may include CPUs that are not usable for migration, + * hence we need to mask them out (cpu_active_map) * * Returns the CPU we should wake onto. */ @@ -961,7 +976,8 @@ static int wake_idle(int cpu, struct task_struct *p) || ((sd->flags & SD_WAKE_IDLE_FAR) && !task_hot(p, task_rq(p)->clock, sd))) { cpus_and(tmp, sd->span, p->cpus_allowed); - for_each_cpu_mask(i, tmp) { + cpus_and(tmp, tmp, cpu_active_map); + for_each_cpu_mask_nr(i, tmp) { if (idle_cpu(i)) { if (i != task_cpu(p)) { schedstat_inc(p, @@ -976,7 +992,7 @@ static int wake_idle(int cpu, struct task_struct *p) } return cpu; } -#else +#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/ static inline int wake_idle(int cpu, struct task_struct *p) { return cpu; @@ -987,46 +1003,143 @@ static inline int wake_idle(int cpu, struct task_struct *p) static const struct sched_class fair_sched_class; +#ifdef CONFIG_FAIR_GROUP_SCHED +/* + * effective_load() calculates the load change as seen from the root_task_group + * + * Adding load to a group doesn't make a group heavier, but can cause movement + * of group shares between cpus. Assuming the shares were perfectly aligned one + * can calculate the shift in shares. + * + * The problem is that perfectly aligning the shares is rather expensive, hence + * we try to avoid doing that too often - see update_shares(), which ratelimits + * this change. + * + * We compensate this by not only taking the current delta into account, but + * also considering the delta between when the shares were last adjusted and + * now. + * + * We still saw a performance dip, some tracing learned us that between + * cgroup:/ and cgroup:/foo balancing the number of affine wakeups increased + * significantly. Therefore try to bias the error in direction of failing + * the affine wakeup. + * + */ +static long effective_load(struct task_group *tg, int cpu, + long wl, long wg) +{ + struct sched_entity *se = tg->se[cpu]; + + if (!tg->parent) + return wl; + + /* + * By not taking the decrease of shares on the other cpu into + * account our error leans towards reducing the affine wakeups. + */ + if (!wl && sched_feat(ASYM_EFF_LOAD)) + return wl; + + for_each_sched_entity(se) { + long S, rw, s, a, b; + long more_w; + + /* + * Instead of using this increment, also add the difference + * between when the shares were last updated and now. + */ + more_w = se->my_q->load.weight - se->my_q->rq_weight; + wl += more_w; + wg += more_w; + + S = se->my_q->tg->shares; + s = se->my_q->shares; + rw = se->my_q->rq_weight; + + a = S*(rw + wl); + b = S*rw + s*wg; + + wl = s*(a-b); + + if (likely(b)) + wl /= b; + + /* + * Assume the group is already running and will + * thus already be accounted for in the weight. + * + * That is, moving shares between CPUs, does not + * alter the group weight. + */ + wg = 0; + } + + return wl; +} + +#else + +static inline unsigned long effective_load(struct task_group *tg, int cpu, + unsigned long wl, unsigned long wg) +{ + return wl; +} + +#endif + static int -wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq, +wake_affine(struct sched_domain *this_sd, struct rq *this_rq, struct task_struct *p, int prev_cpu, int this_cpu, int sync, int idx, unsigned long load, unsigned long this_load, unsigned int imbalance) { struct task_struct *curr = this_rq->curr; + struct task_group *tg; unsigned long tl = this_load; unsigned long tl_per_task; + unsigned long weight; int balanced; if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) return 0; + if (!sync && sched_feat(SYNC_WAKEUPS) && + curr->se.avg_overlap < sysctl_sched_migration_cost && + p->se.avg_overlap < sysctl_sched_migration_cost) + sync = 1; + /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load * of the current CPU: */ - if (sync) - tl -= current->se.load.weight; + if (sync) { + tg = task_group(current); + weight = current->se.load.weight; + + tl += effective_load(tg, this_cpu, -weight, -weight); + load += effective_load(tg, prev_cpu, 0, -weight); + } + + tg = task_group(p); + weight = p->se.load.weight; - balanced = 100*(tl + p->se.load.weight) <= imbalance*load; + balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <= + imbalance*(load + effective_load(tg, prev_cpu, 0, weight)); /* * If the currently running task will sleep within * a reasonable amount of time then attract this newly * woken task: */ - if (sync && balanced && curr->sched_class == &fair_sched_class) { - if (curr->se.avg_overlap < sysctl_sched_migration_cost && - p->se.avg_overlap < sysctl_sched_migration_cost) - return 1; - } + if (sync && balanced) + return 1; schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); - if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) || - balanced) { + if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <= + tl_per_task)) { /* * This domain has SD_WAKE_AFFINE and * p is cache cold in this domain, and @@ -1045,16 +1158,17 @@ static int select_task_rq_fair(struct task_struct *p, int sync) struct sched_domain *sd, *this_sd = NULL; int prev_cpu, this_cpu, new_cpu; unsigned long load, this_load; - struct rq *rq, *this_rq; + struct rq *this_rq; unsigned int imbalance; int idx; prev_cpu = task_cpu(p); - rq = task_rq(p); this_cpu = smp_processor_id(); this_rq = cpu_rq(this_cpu); new_cpu = prev_cpu; + if (prev_cpu == this_cpu) + goto out; /* * 'this_sd' is the first domain that both * this_cpu and prev_cpu are present in: @@ -1082,13 +1196,10 @@ static int select_task_rq_fair(struct task_struct *p, int sync) load = source_load(prev_cpu, idx); this_load = target_load(this_cpu, idx); - if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx, + if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx, load, this_load, imbalance)) return this_cpu; - if (prev_cpu == this_cpu) - goto out; - /* * Start passive balancing when half the imbalance_pct * limit is reached. @@ -1111,64 +1222,24 @@ static unsigned long wakeup_gran(struct sched_entity *se) unsigned long gran = sysctl_sched_wakeup_granularity; /* - * More easily preempt - nice tasks, while not making - * it harder for + nice tasks. + * More easily preempt - nice tasks, while not making it harder for + * + nice tasks. */ - if (unlikely(se->load.weight > NICE_0_LOAD)) - gran = calc_delta_fair(gran, &se->load); + if (sched_feat(ASYM_GRAN)) + gran = calc_delta_mine(gran, NICE_0_LOAD, &se->load); return gran; } /* - * Should 'se' preempt 'curr'. - * - * |s1 - * |s2 - * |s3 - * g - * |<--->|c - * - * w(c, s1) = -1 - * w(c, s2) = 0 - * w(c, s3) = 1 - * - */ -static int -wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) -{ - s64 gran, vdiff = curr->vruntime - se->vruntime; - - if (vdiff < 0) - return -1; - - gran = wakeup_gran(curr); - if (vdiff > gran) - return 1; - - return 0; -} - -/* return depth at which a sched entity is present in the hierarchy */ -static inline int depth_se(struct sched_entity *se) -{ - int depth = 0; - - for_each_sched_entity(se) - depth++; - - return depth; -} - -/* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) { struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); struct sched_entity *se = &curr->se, *pse = &p->se; - int se_depth, pse_depth; + s64 delta_exec; if (unlikely(rt_prio(p->prio))) { update_rq_clock(rq); @@ -1177,13 +1248,19 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) return; } - se->last_wakeup = se->sum_exec_runtime; if (unlikely(se == pse)) return; cfs_rq_of(pse)->next = pse; /* + * We can come here with TIF_NEED_RESCHED already set from new task + * wake up path. + */ + if (test_tsk_need_resched(curr)) + return; + + /* * Batch tasks do not preempt (their preemption is driven by * the tick): */ @@ -1193,33 +1270,15 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) if (!sched_feat(WAKEUP_PREEMPT)) return; - /* - * preemption test can be made between sibling entities who are in the - * same cfs_rq i.e who have a common parent. Walk up the hierarchy of - * both tasks until we find their ancestors who are siblings of common - * parent. - */ - - /* First walk up until both entities are at same depth */ - se_depth = depth_se(se); - pse_depth = depth_se(pse); - - while (se_depth > pse_depth) { - se_depth--; - se = parent_entity(se); - } - - while (pse_depth > se_depth) { - pse_depth--; - pse = parent_entity(pse); - } - - while (!is_same_group(se, pse)) { - se = parent_entity(se); - pse = parent_entity(pse); + if (sched_feat(WAKEUP_OVERLAP) && (sync || + (se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost))) { + resched_task(curr); + return; } - if (wakeup_preempt_entity(se, pse) == 1) + delta_exec = se->sum_exec_runtime - se->prev_sum_exec_runtime; + if (delta_exec > wakeup_gran(pse)) resched_task(curr); } @@ -1278,19 +1337,9 @@ __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next) if (next == &cfs_rq->tasks) return NULL; - /* Skip over entities that are not tasks */ - do { - se = list_entry(next, struct sched_entity, group_node); - next = next->next; - } while (next != &cfs_rq->tasks && !entity_is_task(se)); - - if (next == &cfs_rq->tasks) - return NULL; - - cfs_rq->balance_iterator = next; - - if (entity_is_task(se)) - p = task_of(se); + se = list_entry(next, struct sched_entity, group_node); + p = task_of(se); + cfs_rq->balance_iterator = next->next; return p; } @@ -1309,75 +1358,82 @@ static struct task_struct *load_balance_next_fair(void *arg) return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator); } -#ifdef CONFIG_FAIR_GROUP_SCHED -static int cfs_rq_best_prio(struct cfs_rq *cfs_rq) +static unsigned long +__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, + unsigned long max_load_move, struct sched_domain *sd, + enum cpu_idle_type idle, int *all_pinned, int *this_best_prio, + struct cfs_rq *cfs_rq) { - struct sched_entity *curr; - struct task_struct *p; - - if (!cfs_rq->nr_running || !first_fair(cfs_rq)) - return MAX_PRIO; - - curr = cfs_rq->curr; - if (!curr) - curr = __pick_next_entity(cfs_rq); + struct rq_iterator cfs_rq_iterator; - p = task_of(curr); + cfs_rq_iterator.start = load_balance_start_fair; + cfs_rq_iterator.next = load_balance_next_fair; + cfs_rq_iterator.arg = cfs_rq; - return p->prio; + return balance_tasks(this_rq, this_cpu, busiest, + max_load_move, sd, idle, all_pinned, + this_best_prio, &cfs_rq_iterator); } -#endif +#ifdef CONFIG_FAIR_GROUP_SCHED static unsigned long load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, int *this_best_prio) { - struct cfs_rq *busy_cfs_rq; long rem_load_move = max_load_move; - struct rq_iterator cfs_rq_iterator; - - cfs_rq_iterator.start = load_balance_start_fair; - cfs_rq_iterator.next = load_balance_next_fair; + int busiest_cpu = cpu_of(busiest); + struct task_group *tg; - for_each_leaf_cfs_rq(busiest, busy_cfs_rq) { -#ifdef CONFIG_FAIR_GROUP_SCHED - struct cfs_rq *this_cfs_rq; - long imbalance; - unsigned long maxload; + rcu_read_lock(); + update_h_load(busiest_cpu); - this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu); + list_for_each_entry_rcu(tg, &task_groups, list) { + struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu]; + unsigned long busiest_h_load = busiest_cfs_rq->h_load; + unsigned long busiest_weight = busiest_cfs_rq->load.weight; + u64 rem_load, moved_load; - imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight; - /* Don't pull if this_cfs_rq has more load than busy_cfs_rq */ - if (imbalance <= 0) + /* + * empty group + */ + if (!busiest_cfs_rq->task_weight) continue; - /* Don't pull more than imbalance/2 */ - imbalance /= 2; - maxload = min(rem_load_move, imbalance); + rem_load = (u64)rem_load_move * busiest_weight; + rem_load = div_u64(rem_load, busiest_h_load + 1); - *this_best_prio = cfs_rq_best_prio(this_cfs_rq); -#else -# define maxload rem_load_move -#endif - /* - * pass busy_cfs_rq argument into - * load_balance_[start|next]_fair iterators - */ - cfs_rq_iterator.arg = busy_cfs_rq; - rem_load_move -= balance_tasks(this_rq, this_cpu, busiest, - maxload, sd, idle, all_pinned, - this_best_prio, - &cfs_rq_iterator); + moved_load = __load_balance_fair(this_rq, this_cpu, busiest, + rem_load, sd, idle, all_pinned, this_best_prio, + tg->cfs_rq[busiest_cpu]); + + if (!moved_load) + continue; + + moved_load *= busiest_h_load; + moved_load = div_u64(moved_load, busiest_weight + 1); - if (rem_load_move <= 0) + rem_load_move -= moved_load; + if (rem_load_move < 0) break; } + rcu_read_unlock(); return max_load_move - rem_load_move; } +#else +static unsigned long +load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, + unsigned long max_load_move, + struct sched_domain *sd, enum cpu_idle_type idle, + int *all_pinned, int *this_best_prio) +{ + return __load_balance_fair(this_rq, this_cpu, busiest, + max_load_move, sd, idle, all_pinned, + this_best_prio, &busiest->cfs); +} +#endif static int move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, @@ -1402,7 +1458,7 @@ move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, return 0; } -#endif +#endif /* CONFIG_SMP */ /* * scheduler tick hitting a task of our scheduling class: @@ -1446,10 +1502,10 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) * 'current' within the tree based on its new key value. */ swap(curr->vruntime, se->vruntime); + resched_task(rq->curr); } enqueue_task_fair(rq, p, 0); - resched_task(rq->curr); } /* @@ -1468,7 +1524,7 @@ static void prio_changed_fair(struct rq *rq, struct task_struct *p, if (p->prio > oldprio) resched_task(rq->curr); } else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* @@ -1485,7 +1541,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p, if (running) resched_task(rq->curr); else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* Account for a task changing its policy or group. diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 1c7283c..7c9e8f4 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -1,4 +1,5 @@ SCHED_FEAT(NEW_FAIR_SLEEPERS, 1) +SCHED_FEAT(NORMALIZED_SLEEPER, 1) SCHED_FEAT(WAKEUP_PREEMPT, 1) SCHED_FEAT(START_DEBIT, 1) SCHED_FEAT(AFFINE_WAKEUPS, 1) @@ -6,5 +7,8 @@ SCHED_FEAT(CACHE_HOT_BUDDY, 1) SCHED_FEAT(SYNC_WAKEUPS, 1) SCHED_FEAT(HRTICK, 1) SCHED_FEAT(DOUBLE_TICK, 0) -SCHED_FEAT(NORMALIZED_SLEEPER, 1) -SCHED_FEAT(DEADLINE, 1) +SCHED_FEAT(ASYM_GRAN, 1) +SCHED_FEAT(LB_BIAS, 1) +SCHED_FEAT(LB_WAKEUP_UPDATE, 1) +SCHED_FEAT(ASYM_EFF_LOAD, 1) +SCHED_FEAT(WAKEUP_OVERLAP, 0) diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 3a4f92d..dec4cca 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -14,7 +14,7 @@ static int select_task_rq_idle(struct task_struct *p, int sync) /* * Idle tasks are unconditionally rescheduled: */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p) +static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync) { resched_task(rq->idle); } @@ -76,7 +76,7 @@ static void switched_to_idle(struct rq *rq, struct task_struct *p, if (running) resched_task(rq->curr); else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } static void prio_changed_idle(struct rq *rq, struct task_struct *p, @@ -93,7 +93,7 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p, if (p->prio > oldprio) resched_task(rq->curr); } else - check_preempt_curr(rq, p); + check_preempt_curr(rq, p, 0); } /* diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 0f3c191..cdf5740 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -12,6 +12,9 @@ static inline int rt_overloaded(struct rq *rq) static inline void rt_set_overload(struct rq *rq) { + if (!rq->online) + return; + cpu_set(rq->cpu, rq->rd->rto_mask); /* * Make sure the mask is visible before we set @@ -26,6 +29,9 @@ static inline void rt_set_overload(struct rq *rq) static inline void rt_clear_overload(struct rq *rq) { + if (!rq->online) + return; + /* the order here really doesn't matter */ atomic_dec(&rq->rd->rto_count); cpu_clear(rq->cpu, rq->rd->rto_mask); @@ -96,12 +102,12 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se); static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) { + struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; struct sched_rt_entity *rt_se = rt_rq->rt_se; - if (rt_se && !on_rt_rq(rt_se) && rt_rq->rt_nr_running) { - struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; - - enqueue_rt_entity(rt_se); + if (rt_rq->rt_nr_running) { + if (rt_se && !on_rt_rq(rt_se)) + enqueue_rt_entity(rt_se); if (rt_rq->highest_prio < curr->prio) resched_task(curr); } @@ -155,7 +161,7 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) return &rt_rq->tg->rt_bandwidth; } -#else +#else /* !CONFIG_RT_GROUP_SCHED */ static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) { @@ -193,6 +199,8 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) { + if (rt_rq->rt_nr_running) + resched_task(rq_of_rt_rq(rt_rq)->curr); } static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) @@ -220,14 +228,210 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) return &def_rt_bandwidth; } -#endif +#endif /* CONFIG_RT_GROUP_SCHED */ + +#ifdef CONFIG_SMP +/* + * We ran out of runtime, see if we can borrow some from our neighbours. + */ +static int do_balance_runtime(struct rt_rq *rt_rq) +{ + struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); + struct root_domain *rd = cpu_rq(smp_processor_id())->rd; + int i, weight, more = 0; + u64 rt_period; + + weight = cpus_weight(rd->span); + + spin_lock(&rt_b->rt_runtime_lock); + rt_period = ktime_to_ns(rt_b->rt_period); + for_each_cpu_mask_nr(i, rd->span) { + struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); + s64 diff; + + if (iter == rt_rq) + continue; + + spin_lock(&iter->rt_runtime_lock); + /* + * Either all rqs have inf runtime and there's nothing to steal + * or __disable_runtime() below sets a specific rq to inf to + * indicate its been disabled and disalow stealing. + */ + if (iter->rt_runtime == RUNTIME_INF) + goto next; + + /* + * From runqueues with spare time, take 1/n part of their + * spare time, but no more than our period. + */ + diff = iter->rt_runtime - iter->rt_time; + if (diff > 0) { + diff = div_u64((u64)diff, weight); + if (rt_rq->rt_runtime + diff > rt_period) + diff = rt_period - rt_rq->rt_runtime; + iter->rt_runtime -= diff; + rt_rq->rt_runtime += diff; + more = 1; + if (rt_rq->rt_runtime == rt_period) { + spin_unlock(&iter->rt_runtime_lock); + break; + } + } +next: + spin_unlock(&iter->rt_runtime_lock); + } + spin_unlock(&rt_b->rt_runtime_lock); + + return more; +} + +/* + * Ensure this RQ takes back all the runtime it lend to its neighbours. + */ +static void __disable_runtime(struct rq *rq) +{ + struct root_domain *rd = rq->rd; + struct rt_rq *rt_rq; + + if (unlikely(!scheduler_running)) + return; + + for_each_leaf_rt_rq(rt_rq, rq) { + struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); + s64 want; + int i; + + spin_lock(&rt_b->rt_runtime_lock); + spin_lock(&rt_rq->rt_runtime_lock); + /* + * Either we're all inf and nobody needs to borrow, or we're + * already disabled and thus have nothing to do, or we have + * exactly the right amount of runtime to take out. + */ + if (rt_rq->rt_runtime == RUNTIME_INF || + rt_rq->rt_runtime == rt_b->rt_runtime) + goto balanced; + spin_unlock(&rt_rq->rt_runtime_lock); + + /* + * Calculate the difference between what we started out with + * and what we current have, that's the amount of runtime + * we lend and now have to reclaim. + */ + want = rt_b->rt_runtime - rt_rq->rt_runtime; + + /* + * Greedy reclaim, take back as much as we can. + */ + for_each_cpu_mask(i, rd->span) { + struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); + s64 diff; + + /* + * Can't reclaim from ourselves or disabled runqueues. + */ + if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) + continue; + + spin_lock(&iter->rt_runtime_lock); + if (want > 0) { + diff = min_t(s64, iter->rt_runtime, want); + iter->rt_runtime -= diff; + want -= diff; + } else { + iter->rt_runtime -= want; + want -= want; + } + spin_unlock(&iter->rt_runtime_lock); + + if (!want) + break; + } + + spin_lock(&rt_rq->rt_runtime_lock); + /* + * We cannot be left wanting - that would mean some runtime + * leaked out of the system. + */ + BUG_ON(want); +balanced: + /* + * Disable all the borrow logic by pretending we have inf + * runtime - in which case borrowing doesn't make sense. + */ + rt_rq->rt_runtime = RUNTIME_INF; + spin_unlock(&rt_rq->rt_runtime_lock); + spin_unlock(&rt_b->rt_runtime_lock); + } +} + +static void disable_runtime(struct rq *rq) +{ + unsigned long flags; + + spin_lock_irqsave(&rq->lock, flags); + __disable_runtime(rq); + spin_unlock_irqrestore(&rq->lock, flags); +} + +static void __enable_runtime(struct rq *rq) +{ + struct rt_rq *rt_rq; + + if (unlikely(!scheduler_running)) + return; + + /* + * Reset each runqueue's bandwidth settings + */ + for_each_leaf_rt_rq(rt_rq, rq) { + struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); + + spin_lock(&rt_b->rt_runtime_lock); + spin_lock(&rt_rq->rt_runtime_lock); + rt_rq->rt_runtime = rt_b->rt_runtime; + rt_rq->rt_time = 0; + rt_rq->rt_throttled = 0; + spin_unlock(&rt_rq->rt_runtime_lock); + spin_unlock(&rt_b->rt_runtime_lock); + } +} + +static void enable_runtime(struct rq *rq) +{ + unsigned long flags; + + spin_lock_irqsave(&rq->lock, flags); + __enable_runtime(rq); + spin_unlock_irqrestore(&rq->lock, flags); +} + +static int balance_runtime(struct rt_rq *rt_rq) +{ + int more = 0; + + if (rt_rq->rt_time > rt_rq->rt_runtime) { + spin_unlock(&rt_rq->rt_runtime_lock); + more = do_balance_runtime(rt_rq); + spin_lock(&rt_rq->rt_runtime_lock); + } + + return more; +} +#else /* !CONFIG_SMP */ +static inline int balance_runtime(struct rt_rq *rt_rq) +{ + return 0; +} +#endif /* CONFIG_SMP */ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) { int i, idle = 1; cpumask_t span; - if (rt_b->rt_runtime == RUNTIME_INF) + if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) return 1; span = sched_rt_period_mask(); @@ -241,6 +445,8 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) u64 runtime; spin_lock(&rt_rq->rt_runtime_lock); + if (rt_rq->rt_throttled) + balance_runtime(rt_rq); runtime = rt_rq->rt_runtime; rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { @@ -261,47 +467,6 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) return idle; } -#ifdef CONFIG_SMP -static int balance_runtime(struct rt_rq *rt_rq) -{ - struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); - struct root_domain *rd = cpu_rq(smp_processor_id())->rd; - int i, weight, more = 0; - u64 rt_period; - - weight = cpus_weight(rd->span); - - spin_lock(&rt_b->rt_runtime_lock); - rt_period = ktime_to_ns(rt_b->rt_period); - for_each_cpu_mask(i, rd->span) { - struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); - s64 diff; - - if (iter == rt_rq) - continue; - - spin_lock(&iter->rt_runtime_lock); - diff = iter->rt_runtime - iter->rt_time; - if (diff > 0) { - do_div(diff, weight); - if (rt_rq->rt_runtime + diff > rt_period) - diff = rt_period - rt_rq->rt_runtime; - iter->rt_runtime -= diff; - rt_rq->rt_runtime += diff; - more = 1; - if (rt_rq->rt_runtime == rt_period) { - spin_unlock(&iter->rt_runtime_lock); - break; - } - } - spin_unlock(&iter->rt_runtime_lock); - } - spin_unlock(&rt_b->rt_runtime_lock); - - return more; -} -#endif - static inline int rt_se_prio(struct sched_rt_entity *rt_se) { #ifdef CONFIG_RT_GROUP_SCHED @@ -318,27 +483,16 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) { u64 runtime = sched_rt_runtime(rt_rq); - if (runtime == RUNTIME_INF) - return 0; - if (rt_rq->rt_throttled) return rt_rq_throttled(rt_rq); if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) return 0; -#ifdef CONFIG_SMP - if (rt_rq->rt_time > runtime) { - int more; - - spin_unlock(&rt_rq->rt_runtime_lock); - more = balance_runtime(rt_rq); - spin_lock(&rt_rq->rt_runtime_lock); - - if (more) - runtime = sched_rt_runtime(rt_rq); - } -#endif + balance_runtime(rt_rq); + runtime = sched_rt_runtime(rt_rq); + if (runtime == RUNTIME_INF) + return 0; if (rt_rq->rt_time > runtime) { rt_rq->rt_throttled = 1; @@ -375,13 +529,18 @@ static void update_curr_rt(struct rq *rq) curr->se.exec_start = rq->clock; cpuacct_charge(curr, delta_exec); + if (!rt_bandwidth_enabled()) + return; + for_each_sched_rt_entity(rt_se) { rt_rq = rt_rq_of_se(rt_se); spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_time += delta_exec; - if (sched_rt_runtime_exceeded(rt_rq)) - resched_task(curr); + if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { + rt_rq->rt_time += delta_exec; + if (sched_rt_runtime_exceeded(rt_rq)) + resched_task(curr); + } spin_unlock(&rt_rq->rt_runtime_lock); } } @@ -392,12 +551,23 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) WARN_ON(!rt_prio(rt_se_prio(rt_se))); rt_rq->rt_nr_running++; #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED - if (rt_se_prio(rt_se) < rt_rq->highest_prio) + if (rt_se_prio(rt_se) < rt_rq->highest_prio) { +#ifdef CONFIG_SMP + struct rq *rq = rq_of_rt_rq(rt_rq); +#endif + rt_rq->highest_prio = rt_se_prio(rt_se); +#ifdef CONFIG_SMP + if (rq->online) + cpupri_set(&rq->rd->cpupri, rq->cpu, + rt_se_prio(rt_se)); +#endif + } #endif #ifdef CONFIG_SMP if (rt_se->nr_cpus_allowed > 1) { struct rq *rq = rq_of_rt_rq(rt_rq); + rq->rt.rt_nr_migratory++; } @@ -417,6 +587,10 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) static inline void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) { +#ifdef CONFIG_SMP + int highest_prio = rt_rq->highest_prio; +#endif + WARN_ON(!rt_prio(rt_se_prio(rt_se))); WARN_ON(!rt_rq->rt_nr_running); rt_rq->rt_nr_running--; @@ -440,6 +614,14 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) rq->rt.rt_nr_migratory--; } + if (rt_rq->highest_prio != highest_prio) { + struct rq *rq = rq_of_rt_rq(rt_rq); + + if (rq->online) + cpupri_set(&rq->rd->cpupri, rq->cpu, + rt_rq->highest_prio); + } + update_rt_migration(rq_of_rt_rq(rt_rq)); #endif /* CONFIG_SMP */ #ifdef CONFIG_RT_GROUP_SCHED @@ -455,6 +637,7 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) struct rt_rq *rt_rq = rt_rq_of_se(rt_se); struct rt_prio_array *array = &rt_rq->active; struct rt_rq *group_rq = group_rt_rq(rt_se); + struct list_head *queue = array->queue + rt_se_prio(rt_se); /* * Don't enqueue the group if its throttled, or when empty. @@ -465,7 +648,7 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) return; - list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se)); + list_add_tail(&rt_se->run_list, queue); __set_bit(rt_se_prio(rt_se), array->bitmap); inc_rt_tasks(rt_se, rt_rq); @@ -532,6 +715,8 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) rt_se->timeout = 0; enqueue_rt_entity(rt_se); + + inc_cpu_load(rq, p->se.load.weight); } static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) @@ -540,36 +725,42 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) update_curr_rt(rq); dequeue_rt_entity(rt_se); + + dec_cpu_load(rq, p->se.load.weight); } /* * Put task to the end of the run list without the overhead of dequeue * followed by enqueue. */ -static -void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +static void +requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) { - struct rt_prio_array *array = &rt_rq->active; - struct list_head *queue = array->queue + rt_se_prio(rt_se); + if (on_rt_rq(rt_se)) { + struct rt_prio_array *array = &rt_rq->active; + struct list_head *queue = array->queue + rt_se_prio(rt_se); - if (on_rt_rq(rt_se)) - list_move_tail(&rt_se->run_list, queue); + if (head) + list_move(&rt_se->run_list, queue); + else + list_move_tail(&rt_se->run_list, queue); + } } -static void requeue_task_rt(struct rq *rq, struct task_struct *p) +static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) { struct sched_rt_entity *rt_se = &p->rt; struct rt_rq *rt_rq; for_each_sched_rt_entity(rt_se) { rt_rq = rt_rq_of_se(rt_se); - requeue_rt_entity(rt_rq, rt_se); + requeue_rt_entity(rt_rq, rt_se, head); } } static void yield_task_rt(struct rq *rq) { - requeue_task_rt(rq, rq->curr); + requeue_task_rt(rq, rq->curr, 0); } #ifdef CONFIG_SMP @@ -609,15 +800,58 @@ static int select_task_rq_rt(struct task_struct *p, int sync) */ return task_cpu(p); } + +static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) +{ + cpumask_t mask; + + if (rq->curr->rt.nr_cpus_allowed == 1) + return; + + if (p->rt.nr_cpus_allowed != 1 + && cpupri_find(&rq->rd->cpupri, p, &mask)) + return; + + if (!cpupri_find(&rq->rd->cpupri, rq->curr, &mask)) + return; + + /* + * There appears to be other cpus that can accept + * current and none to run 'p', so lets reschedule + * to try and push current away: + */ + requeue_task_rt(rq, p, 1); + resched_task(rq->curr); +} + #endif /* CONFIG_SMP */ /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p) +static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) { - if (p->prio < rq->curr->prio) + if (p->prio < rq->curr->prio) { resched_task(rq->curr); + return; + } + +#ifdef CONFIG_SMP + /* + * If: + * + * - the newly woken task is of equal priority to the current task + * - the newly woken task is non-migratable while current is migratable + * - current will be preempted on the next reschedule + * + * we should check to see if current can readily move to a different + * cpu. If so, we will reschedule to allow the push logic to try + * to move current somewhere else, making room for our non-migratable + * task. + */ + if (p->prio == rq->curr->prio && !need_resched()) + check_preempt_equal_prio(rq, p); +#endif } static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, @@ -674,6 +908,8 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) #define RT_MAX_TRIES 3 static int double_lock_balance(struct rq *this_rq, struct rq *busiest); +static void double_unlock_balance(struct rq *this_rq, struct rq *busiest); + static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) @@ -720,73 +956,6 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) static DEFINE_PER_CPU(cpumask_t, local_cpu_mask); -static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask) -{ - int lowest_prio = -1; - int lowest_cpu = -1; - int count = 0; - int cpu; - - cpus_and(*lowest_mask, task_rq(task)->rd->online, task->cpus_allowed); - - /* - * Scan each rq for the lowest prio. - */ - for_each_cpu_mask(cpu, *lowest_mask) { - struct rq *rq = cpu_rq(cpu); - - /* We look for lowest RT prio or non-rt CPU */ - if (rq->rt.highest_prio >= MAX_RT_PRIO) { - /* - * if we already found a low RT queue - * and now we found this non-rt queue - * clear the mask and set our bit. - * Otherwise just return the queue as is - * and the count==1 will cause the algorithm - * to use the first bit found. - */ - if (lowest_cpu != -1) { - cpus_clear(*lowest_mask); - cpu_set(rq->cpu, *lowest_mask); - } - return 1; - } - - /* no locking for now */ - if ((rq->rt.highest_prio > task->prio) - && (rq->rt.highest_prio >= lowest_prio)) { - if (rq->rt.highest_prio > lowest_prio) { - /* new low - clear old data */ - lowest_prio = rq->rt.highest_prio; - lowest_cpu = cpu; - count = 0; - } - count++; - } else - cpu_clear(cpu, *lowest_mask); - } - - /* - * Clear out all the set bits that represent - * runqueues that were of higher prio than - * the lowest_prio. - */ - if (lowest_cpu > 0) { - /* - * Perhaps we could add another cpumask op to - * zero out bits. Like cpu_zero_bits(cpumask, nrbits); - * Then that could be optimized to use memset and such. - */ - for_each_cpu_mask(cpu, *lowest_mask) { - if (cpu >= lowest_cpu) - break; - cpu_clear(cpu, *lowest_mask); - } - } - - return count; -} - static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask) { int first; @@ -808,17 +977,19 @@ static int find_lowest_rq(struct task_struct *task) cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask); int this_cpu = smp_processor_id(); int cpu = task_cpu(task); - int count = find_lowest_cpus(task, lowest_mask); - if (!count) + if (task->rt.nr_cpus_allowed == 1) + return -1; /* No other targets possible */ + + if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) return -1; /* No targets found */ /* - * There is no sense in performing an optimal search if only one - * target is found. + * Only consider CPUs that are usable for migration. + * I guess we might want to change cpupri_find() to ignore those + * in the first place. */ - if (count == 1) - return first_cpu(*lowest_mask); + cpus_and(*lowest_mask, *lowest_mask, cpu_active_map); /* * At this point we have built a mask of cpus representing the @@ -900,7 +1071,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) break; /* try again */ - spin_unlock(&lowest_rq->lock); + double_unlock_balance(rq, lowest_rq); lowest_rq = NULL; } @@ -969,7 +1140,7 @@ static int push_rt_task(struct rq *rq) resched_task(lowest_rq->curr); - spin_unlock(&lowest_rq->lock); + double_unlock_balance(rq, lowest_rq); ret = 1; out: @@ -1006,7 +1177,7 @@ static int pull_rt_task(struct rq *this_rq) next = pick_next_task_rt(this_rq); - for_each_cpu_mask(cpu, this_rq->rd->rto_mask) { + for_each_cpu_mask_nr(cpu, this_rq->rd->rto_mask) { if (this_cpu == cpu) continue; @@ -1075,7 +1246,7 @@ static int pull_rt_task(struct rq *this_rq) } skip: - spin_unlock(&src_rq->lock); + double_unlock_balance(this_rq, src_rq); } return ret; @@ -1163,17 +1334,25 @@ static void set_cpus_allowed_rt(struct task_struct *p, } /* Assumes rq->lock is held */ -static void join_domain_rt(struct rq *rq) +static void rq_online_rt(struct rq *rq) { if (rq->rt.overloaded) rt_set_overload(rq); + + __enable_runtime(rq); + + cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio); } /* Assumes rq->lock is held */ -static void leave_domain_rt(struct rq *rq) +static void rq_offline_rt(struct rq *rq) { if (rq->rt.overloaded) rt_clear_overload(rq); + + __disable_runtime(rq); + + cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); } /* @@ -1306,7 +1485,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) * on the queue: */ if (p->rt.run_list.prev != p->rt.run_list.next) { - requeue_task_rt(rq, p); + requeue_task_rt(rq, p, 0); set_tsk_need_resched(p); } } @@ -1336,8 +1515,8 @@ static const struct sched_class rt_sched_class = { .load_balance = load_balance_rt, .move_one_task = move_one_task_rt, .set_cpus_allowed = set_cpus_allowed_rt, - .join_domain = join_domain_rt, - .leave_domain = leave_domain_rt, + .rq_online = rq_online_rt, + .rq_offline = rq_offline_rt, .pre_schedule = pre_schedule_rt, .post_schedule = post_schedule_rt, .task_wake_up = task_wake_up_rt, @@ -1350,3 +1529,17 @@ static const struct sched_class rt_sched_class = { .prio_changed = prio_changed_rt, .switched_to = switched_to_rt, }; + +#ifdef CONFIG_SCHED_DEBUG +extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); + +static void print_rt_stats(struct seq_file *m, int cpu) +{ + struct rt_rq *rt_rq; + + rcu_read_lock(); + for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) + print_rt_rq(m, cpu, rt_rq); + rcu_read_unlock(); +} +#endif /* CONFIG_SCHED_DEBUG */ diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 80179ef..8385d43 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -118,6 +118,13 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta) if (rq) rq->rq_sched_info.cpu_time += delta; } + +static inline void +rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) +{ + if (rq) + rq->rq_sched_info.run_delay += delta; +} # define schedstat_inc(rq, field) do { (rq)->field++; } while (0) # define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0) # define schedstat_set(var, val) do { var = (val); } while (0) @@ -126,6 +133,9 @@ static inline void rq_sched_info_arrive(struct rq *rq, unsigned long long delta) {} static inline void +rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) +{} +static inline void rq_sched_info_depart(struct rq *rq, unsigned long long delta) {} # define schedstat_inc(rq, field) do { } while (0) @@ -134,6 +144,11 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta) #endif #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) +static inline void sched_info_reset_dequeued(struct task_struct *t) +{ + t->sched_info.last_queued = 0; +} + /* * Called when a process is dequeued from the active array and given * the cpu. We should note that with the exception of interactive @@ -143,15 +158,22 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta) * active queue, thus delaying tasks in the expired queue from running; * see scheduler_tick()). * - * This function is only called from sched_info_arrive(), rather than - * dequeue_task(). Even though a task may be queued and dequeued multiple - * times as it is shuffled about, we're really interested in knowing how - * long it was from the *first* time it was queued to the time that it - * finally hit a cpu. + * Though we are interested in knowing how long it was from the *first* time a + * task was queued to the time that it finally hit a cpu, we call this routine + * from dequeue_task() to account for possible rq->clock skew across cpus. The + * delta taken on each cpu would annul the skew. */ static inline void sched_info_dequeued(struct task_struct *t) { - t->sched_info.last_queued = 0; + unsigned long long now = task_rq(t)->clock, delta = 0; + + if (unlikely(sched_info_on())) + if (t->sched_info.last_queued) + delta = now - t->sched_info.last_queued; + sched_info_reset_dequeued(t); + t->sched_info.run_delay += delta; + + rq_sched_info_dequeued(task_rq(t), delta); } /* @@ -165,7 +187,7 @@ static void sched_info_arrive(struct task_struct *t) if (t->sched_info.last_queued) delta = now - t->sched_info.last_queued; - sched_info_dequeued(t); + sched_info_reset_dequeued(t); t->sched_info.run_delay += delta; t->sched_info.last_arrival = now; t->sched_info.pcount++; @@ -242,7 +264,9 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next) __sched_info_switch(prev, next); } #else -#define sched_info_queued(t) do { } while (0) -#define sched_info_switch(t, next) do { } while (0) +#define sched_info_queued(t) do { } while (0) +#define sched_info_reset_dequeued(t) do { } while (0) +#define sched_info_dequeued(t) do { } while (0) +#define sched_info_switch(t, next) do { } while (0) #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */ diff --git a/kernel/semaphore.c b/kernel/semaphore.c index 5c2942e..94a62c0 100644 --- a/kernel/semaphore.c +++ b/kernel/semaphore.c @@ -31,6 +31,7 @@ #include <linux/sched.h> #include <linux/semaphore.h> #include <linux/spinlock.h> +#include <linux/ftrace.h> static noinline void __down(struct semaphore *sem); static noinline int __down_interruptible(struct semaphore *sem); @@ -211,9 +212,7 @@ static inline int __sched __down_common(struct semaphore *sem, long state, waiter.up = 0; for (;;) { - if (state == TASK_INTERRUPTIBLE && signal_pending(task)) - goto interrupted; - if (state == TASK_KILLABLE && fatal_signal_pending(task)) + if (signal_pending_state(state, task)) goto interrupted; if (timeout <= 0) goto timed_out; diff --git a/kernel/signal.c b/kernel/signal.c index 6c0958e..e661b01 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -22,6 +22,7 @@ #include <linux/ptrace.h> #include <linux/signal.h> #include <linux/signalfd.h> +#include <linux/tracehook.h> #include <linux/capability.h> #include <linux/freezer.h> #include <linux/pid_namespace.h> @@ -39,24 +40,21 @@ static struct kmem_cache *sigqueue_cachep; -static int __sig_ignored(struct task_struct *t, int sig) +static void __user *sig_handler(struct task_struct *t, int sig) { - void __user *handler; + return t->sighand->action[sig - 1].sa.sa_handler; +} +static int sig_handler_ignored(void __user *handler, int sig) +{ /* Is it explicitly or implicitly ignored? */ - - handler = t->sighand->action[sig - 1].sa.sa_handler; return handler == SIG_IGN || (handler == SIG_DFL && sig_kernel_ignore(sig)); } static int sig_ignored(struct task_struct *t, int sig) { - /* - * Tracers always want to know about signals.. - */ - if (t->ptrace & PT_PTRACED) - return 0; + void __user *handler; /* * Blocked signals are never ignored, since the @@ -66,7 +64,14 @@ static int sig_ignored(struct task_struct *t, int sig) if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) return 0; - return __sig_ignored(t, sig); + handler = sig_handler(t, sig); + if (!sig_handler_ignored(handler, sig)) + return 0; + + /* + * Tracers may want to know about even ignored signals. + */ + return !tracehook_consider_ignored_signal(t, sig, handler); } /* @@ -129,7 +134,9 @@ void recalc_sigpending_and_wake(struct task_struct *t) void recalc_sigpending(void) { - if (!recalc_sigpending_tsk(current) && !freezing(current)) + if (unlikely(tracehook_force_sigpending())) + set_thread_flag(TIF_SIGPENDING); + else if (!recalc_sigpending_tsk(current) && !freezing(current)) clear_thread_flag(TIF_SIGPENDING); } @@ -295,12 +302,12 @@ flush_signal_handlers(struct task_struct *t, int force_default) int unhandled_signal(struct task_struct *tsk, int sig) { + void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; if (is_global_init(tsk)) return 1; - if (tsk->ptrace & PT_PTRACED) + if (handler != SIG_IGN && handler != SIG_DFL) return 0; - return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) || - (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL); + return !tracehook_consider_fatal_signal(tsk, sig, handler); } @@ -338,13 +345,9 @@ unblock_all_signals(void) spin_unlock_irqrestore(¤t->sighand->siglock, flags); } -static int collect_signal(int sig, struct sigpending *list, siginfo_t *info) +static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) { struct sigqueue *q, *first = NULL; - int still_pending = 0; - - if (unlikely(!sigismember(&list->signal, sig))) - return 0; /* * Collect the siginfo appropriate to this signal. Check if @@ -352,33 +355,30 @@ static int collect_signal(int sig, struct sigpending *list, siginfo_t *info) */ list_for_each_entry(q, &list->list, list) { if (q->info.si_signo == sig) { - if (first) { - still_pending = 1; - break; - } + if (first) + goto still_pending; first = q; } } + + sigdelset(&list->signal, sig); + if (first) { +still_pending: list_del_init(&first->list); copy_siginfo(info, &first->info); __sigqueue_free(first); - if (!still_pending) - sigdelset(&list->signal, sig); } else { - /* Ok, it wasn't in the queue. This must be a fast-pathed signal or we must have been out of queue space. So zero out the info. */ - sigdelset(&list->signal, sig); info->si_signo = sig; info->si_errno = 0; info->si_code = 0; info->si_pid = 0; info->si_uid = 0; } - return 1; } static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, @@ -396,8 +396,7 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, } } - if (!collect_signal(sig, pending, info)) - sig = 0; + collect_signal(sig, pending, info); } return sig; @@ -462,8 +461,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) * is to alert stop-signal processing code when another * processor has come along and cleared the flag. */ - if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) - tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; + tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; } if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { /* @@ -600,9 +598,6 @@ static int check_kill_permission(int sig, struct siginfo *info, return security_task_kill(t, info, sig, 0); } -/* forward decl */ -static void do_notify_parent_cldstop(struct task_struct *tsk, int why); - /* * Handle magic process-wide effects of stop/continue signals. Unlike * the signal actions, these happen immediately at signal-generation @@ -765,7 +760,8 @@ static void complete_signal(int sig, struct task_struct *p, int group) if (sig_fatal(p, sig) && !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && !sigismember(&t->real_blocked, sig) && - (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) { + (sig == SIGKILL || + !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) { /* * This signal will be fatal to the whole group. */ @@ -1125,7 +1121,7 @@ EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); * is probably wrong. Should make it like BSD or SYSV. */ -static int kill_something_info(int sig, struct siginfo *info, int pid) +static int kill_something_info(int sig, struct siginfo *info, pid_t pid) { int ret; @@ -1237,17 +1233,6 @@ int kill_pid(struct pid *pid, int sig, int priv) } EXPORT_SYMBOL(kill_pid); -int -kill_proc(pid_t pid, int sig, int priv) -{ - int ret; - - rcu_read_lock(); - ret = kill_pid_info(sig, __si_special(priv), find_pid(pid)); - rcu_read_unlock(); - return ret; -} - /* * These functions support sending signals using preallocated sigqueue * structures. This is needed "because realtime applications cannot @@ -1319,6 +1304,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) q->info.si_overrun++; goto out; } + q->info.si_overrun = 0; signalfd_notify(t, sig); pending = group ? &t->signal->shared_pending : &t->pending; @@ -1343,13 +1329,16 @@ static inline void __wake_up_parent(struct task_struct *p, /* * Let a parent know about the death of a child. * For a stopped/continued status change, use do_notify_parent_cldstop instead. + * + * Returns -1 if our parent ignored us and so we've switched to + * self-reaping, or else @sig. */ - -void do_notify_parent(struct task_struct *tsk, int sig) +int do_notify_parent(struct task_struct *tsk, int sig) { struct siginfo info; unsigned long flags; struct sighand_struct *psig; + int ret = sig; BUG_ON(sig == -1); @@ -1379,10 +1368,9 @@ void do_notify_parent(struct task_struct *tsk, int sig) info.si_uid = tsk->uid; - /* FIXME: find out whether or not this is supposed to be c*time. */ - info.si_utime = cputime_to_jiffies(cputime_add(tsk->utime, + info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, tsk->signal->utime)); - info.si_stime = cputime_to_jiffies(cputime_add(tsk->stime, + info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, tsk->signal->stime)); info.si_status = tsk->exit_code & 0x7f; @@ -1415,14 +1403,16 @@ void do_notify_parent(struct task_struct *tsk, int sig) * is implementation-defined: we do (if you don't want * it, just use SIG_IGN instead). */ - tsk->exit_signal = -1; + ret = tsk->exit_signal = -1; if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) - sig = 0; + sig = -1; } if (valid_signal(sig) && sig > 0) __group_send_sig_info(sig, &info, tsk->parent); __wake_up_parent(tsk, tsk->parent); spin_unlock_irqrestore(&psig->siglock, flags); + + return ret; } static void do_notify_parent_cldstop(struct task_struct *tsk, int why) @@ -1450,9 +1440,8 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why) info.si_uid = tsk->uid; - /* FIXME: find out whether or not this is supposed to be c*time. */ - info.si_utime = cputime_to_jiffies(tsk->utime); - info.si_stime = cputime_to_jiffies(tsk->stime); + info.si_utime = cputime_to_clock_t(tsk->utime); + info.si_stime = cputime_to_clock_t(tsk->stime); info.si_code = why; switch (why) { @@ -1491,10 +1480,10 @@ static inline int may_ptrace_stop(void) * is a deadlock situation, and pointless because our tracer * is dead so don't allow us to stop. * If SIGKILL was already sent before the caller unlocked - * ->siglock we must see ->core_waiters != 0. Otherwise it + * ->siglock we must see ->core_state != NULL. Otherwise it * is safe to enter schedule(). */ - if (unlikely(current->mm->core_waiters) && + if (unlikely(current->mm->core_state) && unlikely(current->mm == current->parent->mm)) return 0; @@ -1507,9 +1496,8 @@ static inline int may_ptrace_stop(void) */ static int sigkill_pending(struct task_struct *tsk) { - return ((sigismember(&tsk->pending.signal, SIGKILL) || - sigismember(&tsk->signal->shared_pending.signal, SIGKILL)) && - !unlikely(sigismember(&tsk->blocked, SIGKILL))); + return sigismember(&tsk->pending.signal, SIGKILL) || + sigismember(&tsk->signal->shared_pending.signal, SIGKILL); } /* @@ -1525,8 +1513,6 @@ static int sigkill_pending(struct task_struct *tsk) */ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) { - int killed = 0; - if (arch_ptrace_stop_needed(exit_code, info)) { /* * The arch code has something special to do before a @@ -1542,7 +1528,8 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) spin_unlock_irq(¤t->sighand->siglock); arch_ptrace_stop(exit_code, info); spin_lock_irq(¤t->sighand->siglock); - killed = sigkill_pending(current); + if (sigkill_pending(current)) + return; } /* @@ -1559,7 +1546,7 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) __set_current_state(TASK_TRACED); spin_unlock_irq(¤t->sighand->siglock); read_lock(&tasklist_lock); - if (!unlikely(killed) && may_ptrace_stop()) { + if (may_ptrace_stop()) { do_notify_parent_cldstop(current, CLD_TRAPPED); read_unlock(&tasklist_lock); schedule(); @@ -1623,7 +1610,7 @@ finish_stop(int stop_count) * a group stop in progress and we are the last to stop, * report to the parent. When ptraced, every thread reports itself. */ - if (stop_count == 0 || (current->ptrace & PT_PTRACED)) { + if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) { read_lock(&tasklist_lock); do_notify_parent_cldstop(current, CLD_STOPPED); read_unlock(&tasklist_lock); @@ -1658,8 +1645,7 @@ static int do_signal_stop(int signr) } else { struct task_struct *t; - if (unlikely((sig->flags & (SIGNAL_STOP_DEQUEUED | SIGNAL_UNKILLABLE)) - != SIGNAL_STOP_DEQUEUED) || + if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) || unlikely(signal_group_exit(sig))) return 0; /* @@ -1760,6 +1746,9 @@ relock: signal->flags &= ~SIGNAL_CLD_MASK; spin_unlock_irq(&sighand->siglock); + if (unlikely(!tracehook_notify_jctl(1, why))) + goto relock; + read_lock(&tasklist_lock); do_notify_parent_cldstop(current->group_leader, why); read_unlock(&tasklist_lock); @@ -1773,17 +1762,33 @@ relock: do_signal_stop(0)) goto relock; - signr = dequeue_signal(current, ¤t->blocked, info); - if (!signr) - break; /* will return 0 */ + /* + * Tracing can induce an artifical signal and choose sigaction. + * The return value in @signr determines the default action, + * but @info->si_signo is the signal number we will report. + */ + signr = tracehook_get_signal(current, regs, info, return_ka); + if (unlikely(signr < 0)) + goto relock; + if (unlikely(signr != 0)) + ka = return_ka; + else { + signr = dequeue_signal(current, ¤t->blocked, + info); - if (signr != SIGKILL) { - signr = ptrace_signal(signr, info, regs, cookie); if (!signr) - continue; + break; /* will return 0 */ + + if (signr != SIGKILL) { + signr = ptrace_signal(signr, info, + regs, cookie); + if (!signr) + continue; + } + + ka = &sighand->action[signr-1]; } - ka = &sighand->action[signr-1]; if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ continue; if (ka->sa.sa_handler != SIG_DFL) { @@ -1831,7 +1836,7 @@ relock: spin_lock_irq(&sighand->siglock); } - if (likely(do_signal_stop(signr))) { + if (likely(do_signal_stop(info->si_signo))) { /* It released the siglock. */ goto relock; } @@ -1852,7 +1857,7 @@ relock: if (sig_kernel_coredump(signr)) { if (print_fatal_signals) - print_fatal_signal(regs, signr); + print_fatal_signal(regs, info->si_signo); /* * If it was able to dump core, this kills all * other threads in the group and synchronizes with @@ -1861,13 +1866,13 @@ relock: * first and our do_group_exit call below will use * that value and ignore the one we pass it. */ - do_coredump((long)signr, signr, regs); + do_coredump(info->si_signo, info->si_signo, regs); } /* * Death signals, no core dump. */ - do_group_exit(signr); + do_group_exit(info->si_signo); /* NOTREACHED */ } spin_unlock_irq(&sighand->siglock); @@ -1909,7 +1914,7 @@ void exit_signals(struct task_struct *tsk) out: spin_unlock_irq(&tsk->sighand->siglock); - if (unlikely(group_stop)) { + if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) { read_lock(&tasklist_lock); do_notify_parent_cldstop(tsk, CLD_STOPPED); read_unlock(&tasklist_lock); @@ -1920,8 +1925,6 @@ EXPORT_SYMBOL(recalc_sigpending); EXPORT_SYMBOL_GPL(dequeue_signal); EXPORT_SYMBOL(flush_signals); EXPORT_SYMBOL(force_sig); -EXPORT_SYMBOL(kill_proc); -EXPORT_SYMBOL(ptrace_notify); EXPORT_SYMBOL(send_sig); EXPORT_SYMBOL(send_sig_info); EXPORT_SYMBOL(sigprocmask); @@ -2196,7 +2199,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese, } asmlinkage long -sys_kill(int pid, int sig) +sys_kill(pid_t pid, int sig) { struct siginfo info; @@ -2209,7 +2212,7 @@ sys_kill(int pid, int sig) return kill_something_info(sig, &info, pid); } -static int do_tkill(int tgid, int pid, int sig) +static int do_tkill(pid_t tgid, pid_t pid, int sig) { int error; struct siginfo info; @@ -2255,7 +2258,7 @@ static int do_tkill(int tgid, int pid, int sig) * exists but it's not belonging to the target process anymore. This * method solves the problem of threads exiting and PIDs getting reused. */ -asmlinkage long sys_tgkill(int tgid, int pid, int sig) +asmlinkage long sys_tgkill(pid_t tgid, pid_t pid, int sig) { /* This is only valid for single tasks */ if (pid <= 0 || tgid <= 0) @@ -2268,7 +2271,7 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig) * Send a signal to only one task, even if it's a CLONE_THREAD task. */ asmlinkage long -sys_tkill(int pid, int sig) +sys_tkill(pid_t pid, int sig) { /* This is only valid for single tasks */ if (pid <= 0) @@ -2278,7 +2281,7 @@ sys_tkill(int pid, int sig) } asmlinkage long -sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo) +sys_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t __user *uinfo) { siginfo_t info; @@ -2325,7 +2328,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) * (for example, SIGCHLD), shall cause the pending signal to * be discarded, whether or not it is blocked" */ - if (__sig_ignored(t, sig)) { + if (sig_handler_ignored(sig_handler(t, sig), sig)) { sigemptyset(&mask); sigaddset(&mask, sig); rm_from_queue_full(&mask, &t->signal->shared_pending); diff --git a/kernel/smp.c b/kernel/smp.c new file mode 100644 index 0000000..f362a85 --- /dev/null +++ b/kernel/smp.c @@ -0,0 +1,431 @@ +/* + * Generic helpers for smp ipi calls + * + * (C) Jens Axboe <jens.axboe@oracle.com> 2008 + * + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/rcupdate.h> +#include <linux/rculist.h> +#include <linux/smp.h> + +static DEFINE_PER_CPU(struct call_single_queue, call_single_queue); +static LIST_HEAD(call_function_queue); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(call_function_lock); + +enum { + CSD_FLAG_WAIT = 0x01, + CSD_FLAG_ALLOC = 0x02, +}; + +struct call_function_data { + struct call_single_data csd; + spinlock_t lock; + unsigned int refs; + cpumask_t cpumask; + struct rcu_head rcu_head; +}; + +struct call_single_queue { + struct list_head list; + spinlock_t lock; +}; + +static int __cpuinit init_call_single_data(void) +{ + int i; + + for_each_possible_cpu(i) { + struct call_single_queue *q = &per_cpu(call_single_queue, i); + + spin_lock_init(&q->lock); + INIT_LIST_HEAD(&q->list); + } + return 0; +} +early_initcall(init_call_single_data); + +static void csd_flag_wait(struct call_single_data *data) +{ + /* Wait for response */ + do { + /* + * We need to see the flags store in the IPI handler + */ + smp_mb(); + if (!(data->flags & CSD_FLAG_WAIT)) + break; + cpu_relax(); + } while (1); +} + +/* + * Insert a previously allocated call_single_data element for execution + * on the given CPU. data must already have ->func, ->info, and ->flags set. + */ +static void generic_exec_single(int cpu, struct call_single_data *data) +{ + struct call_single_queue *dst = &per_cpu(call_single_queue, cpu); + int wait = data->flags & CSD_FLAG_WAIT, ipi; + unsigned long flags; + + spin_lock_irqsave(&dst->lock, flags); + ipi = list_empty(&dst->list); + list_add_tail(&data->list, &dst->list); + spin_unlock_irqrestore(&dst->lock, flags); + + if (ipi) + arch_send_call_function_single_ipi(cpu); + + if (wait) + csd_flag_wait(data); +} + +static void rcu_free_call_data(struct rcu_head *head) +{ + struct call_function_data *data; + + data = container_of(head, struct call_function_data, rcu_head); + + kfree(data); +} + +/* + * Invoked by arch to handle an IPI for call function. Must be called with + * interrupts disabled. + */ +void generic_smp_call_function_interrupt(void) +{ + struct call_function_data *data; + int cpu = get_cpu(); + + /* + * It's ok to use list_for_each_rcu() here even though we may delete + * 'pos', since list_del_rcu() doesn't clear ->next + */ + rcu_read_lock(); + list_for_each_entry_rcu(data, &call_function_queue, csd.list) { + int refs; + + if (!cpu_isset(cpu, data->cpumask)) + continue; + + data->csd.func(data->csd.info); + + spin_lock(&data->lock); + cpu_clear(cpu, data->cpumask); + WARN_ON(data->refs == 0); + data->refs--; + refs = data->refs; + spin_unlock(&data->lock); + + if (refs) + continue; + + spin_lock(&call_function_lock); + list_del_rcu(&data->csd.list); + spin_unlock(&call_function_lock); + + if (data->csd.flags & CSD_FLAG_WAIT) { + /* + * serialize stores to data with the flag clear + * and wakeup + */ + smp_wmb(); + data->csd.flags &= ~CSD_FLAG_WAIT; + } + if (data->csd.flags & CSD_FLAG_ALLOC) + call_rcu(&data->rcu_head, rcu_free_call_data); + } + rcu_read_unlock(); + + put_cpu(); +} + +/* + * Invoked by arch to handle an IPI for call function single. Must be called + * from the arch with interrupts disabled. + */ +void generic_smp_call_function_single_interrupt(void) +{ + struct call_single_queue *q = &__get_cpu_var(call_single_queue); + LIST_HEAD(list); + + /* + * Need to see other stores to list head for checking whether + * list is empty without holding q->lock + */ + smp_mb(); + while (!list_empty(&q->list)) { + unsigned int data_flags; + + spin_lock(&q->lock); + list_replace_init(&q->list, &list); + spin_unlock(&q->lock); + + while (!list_empty(&list)) { + struct call_single_data *data; + + data = list_entry(list.next, struct call_single_data, + list); + list_del(&data->list); + + /* + * 'data' can be invalid after this call if + * flags == 0 (when called through + * generic_exec_single(), so save them away before + * making the call. + */ + data_flags = data->flags; + + data->func(data->info); + + if (data_flags & CSD_FLAG_WAIT) { + smp_wmb(); + data->flags &= ~CSD_FLAG_WAIT; + } else if (data_flags & CSD_FLAG_ALLOC) + kfree(data); + } + /* + * See comment on outer loop + */ + smp_mb(); + } +} + +/* + * smp_call_function_single - Run a function on a specific CPU + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @wait: If true, wait until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. Note that @wait + * will be implicitly turned on in case of allocation failures, since + * we fall back to on-stack allocation. + */ +int smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int wait) +{ + struct call_single_data d; + unsigned long flags; + /* prevent preemption and reschedule on another processor, + as well as CPU removal */ + int me = get_cpu(); + int err = 0; + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + + if (cpu == me) { + local_irq_save(flags); + func(info); + local_irq_restore(flags); + } else if ((unsigned)cpu < NR_CPUS && cpu_online(cpu)) { + struct call_single_data *data = NULL; + + if (!wait) { + data = kmalloc(sizeof(*data), GFP_ATOMIC); + if (data) + data->flags = CSD_FLAG_ALLOC; + } + if (!data) { + data = &d; + data->flags = CSD_FLAG_WAIT; + } + + data->func = func; + data->info = info; + generic_exec_single(cpu, data); + } else { + err = -ENXIO; /* CPU not online */ + } + + put_cpu(); + return err; +} +EXPORT_SYMBOL(smp_call_function_single); + +/** + * __smp_call_function_single(): Run a function on another CPU + * @cpu: The CPU to run on. + * @data: Pre-allocated and setup data structure + * + * Like smp_call_function_single(), but allow caller to pass in a pre-allocated + * data structure. Useful for embedding @data inside other structures, for + * instance. + * + */ +void __smp_call_function_single(int cpu, struct call_single_data *data) +{ + /* Can deadlock when called with interrupts disabled */ + WARN_ON((data->flags & CSD_FLAG_WAIT) && irqs_disabled()); + + generic_exec_single(cpu, data); +} + +/* Dummy function */ +static void quiesce_dummy(void *unused) +{ +} + +/* + * Ensure stack based data used in call function mask is safe to free. + * + * This is needed by smp_call_function_mask when using on-stack data, because + * a single call function queue is shared by all CPUs, and any CPU may pick up + * the data item on the queue at any time before it is deleted. So we need to + * ensure that all CPUs have transitioned through a quiescent state after + * this call. + * + * This is a very slow function, implemented by sending synchronous IPIs to + * all possible CPUs. For this reason, we have to alloc data rather than use + * stack based data even in the case of synchronous calls. The stack based + * data is then just used for deadlock/oom fallback which will be very rare. + * + * If a faster scheme can be made, we could go back to preferring stack based + * data -- the data allocation/free is non-zero cost. + */ +static void smp_call_function_mask_quiesce_stack(cpumask_t mask) +{ + struct call_single_data data; + int cpu; + + data.func = quiesce_dummy; + data.info = NULL; + + for_each_cpu_mask(cpu, mask) { + data.flags = CSD_FLAG_WAIT; + generic_exec_single(cpu, &data); + } +} + +/** + * smp_call_function_mask(): Run a function on a set of other CPUs. + * @mask: The set of cpus to run on. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @wait: If true, wait (atomically) until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. + * + * If @wait is true, then returns once @func has returned. Note that @wait + * will be implicitly turned on in case of allocation failures, since + * we fall back to on-stack allocation. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. Preemption + * must be disabled when calling this function. + */ +int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info, + int wait) +{ + struct call_function_data d; + struct call_function_data *data = NULL; + cpumask_t allbutself; + unsigned long flags; + int cpu, num_cpus; + int slowpath = 0; + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + + cpu = smp_processor_id(); + allbutself = cpu_online_map; + cpu_clear(cpu, allbutself); + cpus_and(mask, mask, allbutself); + num_cpus = cpus_weight(mask); + + /* + * If zero CPUs, return. If just a single CPU, turn this request + * into a targetted single call instead since it's faster. + */ + if (!num_cpus) + return 0; + else if (num_cpus == 1) { + cpu = first_cpu(mask); + return smp_call_function_single(cpu, func, info, wait); + } + + data = kmalloc(sizeof(*data), GFP_ATOMIC); + if (data) { + data->csd.flags = CSD_FLAG_ALLOC; + if (wait) + data->csd.flags |= CSD_FLAG_WAIT; + } else { + data = &d; + data->csd.flags = CSD_FLAG_WAIT; + wait = 1; + slowpath = 1; + } + + spin_lock_init(&data->lock); + data->csd.func = func; + data->csd.info = info; + data->refs = num_cpus; + data->cpumask = mask; + + spin_lock_irqsave(&call_function_lock, flags); + list_add_tail_rcu(&data->csd.list, &call_function_queue); + spin_unlock_irqrestore(&call_function_lock, flags); + + /* Send a message to all CPUs in the map */ + arch_send_call_function_ipi(mask); + + /* optionally wait for the CPUs to complete */ + if (wait) { + csd_flag_wait(&data->csd); + if (unlikely(slowpath)) + smp_call_function_mask_quiesce_stack(mask); + } + + return 0; +} +EXPORT_SYMBOL(smp_call_function_mask); + +/** + * smp_call_function(): Run a function on all other CPUs. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @wait: If true, wait (atomically) until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. + * + * If @wait is true, then returns once @func has returned; otherwise + * it returns just before the target cpu calls @func. In case of allocation + * failure, @wait will be implicitly turned on. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. + */ +int smp_call_function(void (*func)(void *), void *info, int wait) +{ + int ret; + + preempt_disable(); + ret = smp_call_function_mask(cpu_online_map, func, info, wait); + preempt_enable(); + return ret; +} +EXPORT_SYMBOL(smp_call_function); + +void ipi_call_lock(void) +{ + spin_lock(&call_function_lock); +} + +void ipi_call_unlock(void) +{ + spin_unlock(&call_function_lock); +} + +void ipi_call_lock_irq(void) +{ + spin_lock_irq(&call_function_lock); +} + +void ipi_call_unlock_irq(void) +{ + spin_unlock_irq(&call_function_lock); +} diff --git a/kernel/softirq.c b/kernel/softirq.c index 36e0617..c506f26 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -131,23 +131,17 @@ void _local_bh_enable(void) EXPORT_SYMBOL(_local_bh_enable); -void local_bh_enable(void) +static inline void _local_bh_enable_ip(unsigned long ip) { + WARN_ON_ONCE(in_irq() || irqs_disabled()); #ifdef CONFIG_TRACE_IRQFLAGS - unsigned long flags; - - WARN_ON_ONCE(in_irq()); -#endif - WARN_ON_ONCE(irqs_disabled()); - -#ifdef CONFIG_TRACE_IRQFLAGS - local_irq_save(flags); + local_irq_disable(); #endif /* * Are softirqs going to be turned on now: */ if (softirq_count() == SOFTIRQ_OFFSET) - trace_softirqs_on((unsigned long)__builtin_return_address(0)); + trace_softirqs_on(ip); /* * Keep preemption disabled until we are done with * softirq processing: @@ -159,40 +153,20 @@ void local_bh_enable(void) dec_preempt_count(); #ifdef CONFIG_TRACE_IRQFLAGS - local_irq_restore(flags); + local_irq_enable(); #endif preempt_check_resched(); } + +void local_bh_enable(void) +{ + _local_bh_enable_ip((unsigned long)__builtin_return_address(0)); +} EXPORT_SYMBOL(local_bh_enable); void local_bh_enable_ip(unsigned long ip) { -#ifdef CONFIG_TRACE_IRQFLAGS - unsigned long flags; - - WARN_ON_ONCE(in_irq()); - - local_irq_save(flags); -#endif - /* - * Are softirqs going to be turned on now: - */ - if (softirq_count() == SOFTIRQ_OFFSET) - trace_softirqs_on(ip); - /* - * Keep preemption disabled until we are done with - * softirq processing: - */ - sub_preempt_count(SOFTIRQ_OFFSET - 1); - - if (unlikely(!in_interrupt() && local_softirq_pending())) - do_softirq(); - - dec_preempt_count(); -#ifdef CONFIG_TRACE_IRQFLAGS - local_irq_restore(flags); -#endif - preempt_check_resched(); + _local_bh_enable_ip(ip); } EXPORT_SYMBOL(local_bh_enable_ip); @@ -312,7 +286,7 @@ void irq_exit(void) #ifdef CONFIG_NO_HZ /* Make sure that timer wheel updates are propagated */ if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched()) - tick_nohz_stop_sched_tick(); + tick_nohz_stop_sched_tick(0); rcu_irq_exit(); #endif preempt_enable_no_resched(); @@ -347,9 +321,8 @@ void raise_softirq(unsigned int nr) local_irq_restore(flags); } -void open_softirq(int nr, void (*action)(struct softirq_action*), void *data) +void open_softirq(int nr, void (*action)(struct softirq_action *)) { - softirq_vec[nr].data = data; softirq_vec[nr].action = action; } @@ -360,10 +333,8 @@ struct tasklet_head struct tasklet_struct **tail; }; -/* Some compilers disobey section attribute on statics when not - initialized -- RR */ -static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec) = { NULL }; -static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec) = { NULL }; +static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec); +static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec); void __tasklet_schedule(struct tasklet_struct *t) { @@ -503,8 +474,8 @@ void __init softirq_init(void) &per_cpu(tasklet_hi_vec, cpu).head; } - open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); - open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); + open_softirq(TASKLET_SOFTIRQ, tasklet_action); + open_softirq(HI_SOFTIRQ, tasklet_hi_action); } static int ksoftirqd(void * __bind_cpu) @@ -645,7 +616,7 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb, p = per_cpu(ksoftirqd, hotcpu); per_cpu(ksoftirqd, hotcpu) = NULL; - sched_setscheduler(p, SCHED_FIFO, ¶m); + sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); kthread_stop(p); takeover_tasklets(hotcpu); break; @@ -659,7 +630,7 @@ static struct notifier_block __cpuinitdata cpu_nfb = { .notifier_call = cpu_callback }; -__init int spawn_ksoftirqd(void) +static __init int spawn_ksoftirqd(void) { void *cpu = (void *)(long)smp_processor_id(); int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); @@ -669,17 +640,18 @@ __init int spawn_ksoftirqd(void) register_cpu_notifier(&cpu_nfb); return 0; } +early_initcall(spawn_ksoftirqd); #ifdef CONFIG_SMP /* * Call a function on all processors */ -int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait) +int on_each_cpu(void (*func) (void *info), void *info, int wait) { int ret = 0; preempt_disable(); - ret = smp_call_function(func, info, retry, wait); + ret = smp_call_function(func, info, wait); local_irq_disable(); func(info); local_irq_enable(); diff --git a/kernel/softlockup.c b/kernel/softlockup.c index c828c23..cb838ee 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -13,6 +13,7 @@ #include <linux/delay.h> #include <linux/freezer.h> #include <linux/kthread.h> +#include <linux/lockdep.h> #include <linux/notifier.h> #include <linux/module.h> @@ -25,7 +26,22 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp); static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int __read_mostly did_panic; -unsigned long __read_mostly softlockup_thresh = 60; +int __read_mostly softlockup_thresh = 60; + +/* + * Should we panic (and reboot, if panic_timeout= is set) when a + * soft-lockup occurs: + */ +unsigned int __read_mostly softlockup_panic = + CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; + +static int __init softlockup_panic_setup(char *str) +{ + softlockup_panic = simple_strtoul(str, NULL, 0); + + return 1; +} +__setup("softlockup_panic=", softlockup_panic_setup); static int softlock_panic(struct notifier_block *this, unsigned long event, void *ptr) @@ -84,6 +100,14 @@ void softlockup_tick(void) struct pt_regs *regs = get_irq_regs(); unsigned long now; + /* Is detection switched off? */ + if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) { + /* Be sure we don't false trigger if switched back on */ + if (touch_timestamp) + per_cpu(touch_timestamp, this_cpu) = 0; + return; + } + if (touch_timestamp == 0) { __touch_softlockup_watchdog(); return; @@ -92,11 +116,8 @@ void softlockup_tick(void) print_timestamp = per_cpu(print_timestamp, this_cpu); /* report at most once a second */ - if ((print_timestamp >= touch_timestamp && - print_timestamp < (touch_timestamp + 1)) || - did_panic || !per_cpu(watchdog_task, this_cpu)) { + if (print_timestamp == touch_timestamp || did_panic) return; - } /* do not print during early bootup: */ if (unlikely(system_state != SYSTEM_RUNNING)) { @@ -106,8 +127,11 @@ void softlockup_tick(void) now = get_timestamp(this_cpu); - /* Wake up the high-prio watchdog task every second: */ - if (now > (touch_timestamp + 1)) + /* + * Wake up the high-prio watchdog task twice per + * threshold timespan. + */ + if (now > touch_timestamp + softlockup_thresh/2) wake_up_process(per_cpu(watchdog_task, this_cpu)); /* Warn about unreasonable delays: */ @@ -120,11 +144,16 @@ void softlockup_tick(void) printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n", this_cpu, now - touch_timestamp, current->comm, task_pid_nr(current)); + print_modules(); + print_irqtrace_events(current); if (regs) show_regs(regs); else dump_stack(); spin_unlock(&print_lock); + + if (softlockup_panic) + panic("softlockup: hung tasks"); } /* @@ -177,6 +206,9 @@ static void check_hung_task(struct task_struct *t, unsigned long now) t->last_switch_timestamp = now; touch_nmi_watchdog(); + + if (softlockup_panic) + panic("softlockup: blocked tasks"); } /* @@ -201,7 +233,8 @@ static void check_hung_uninterruptible_tasks(int this_cpu) do_each_thread(g, t) { if (!--max_count) goto unlock; - if (t->state & TASK_UNINTERRUPTIBLE) + /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */ + if (t->state == TASK_UNINTERRUPTIBLE) check_hung_task(t, now); } while_each_thread(g, t); unlock: @@ -306,14 +339,33 @@ static struct notifier_block __cpuinitdata cpu_nfb = { .notifier_call = cpu_callback }; -__init void spawn_softlockup_task(void) +static int __initdata nosoftlockup; + +static int __init nosoftlockup_setup(char *str) +{ + nosoftlockup = 1; + return 1; +} +__setup("nosoftlockup", nosoftlockup_setup); + +static int __init spawn_softlockup_task(void) { void *cpu = (void *)(long)smp_processor_id(); - int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + int err; + + if (nosoftlockup) + return 0; - BUG_ON(err == NOTIFY_BAD); + err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + if (err == NOTIFY_BAD) { + BUG(); + return 1; + } cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); register_cpu_notifier(&cpu_nfb); atomic_notifier_chain_register(&panic_notifier_list, &panic_block); + + return 0; } +early_initcall(spawn_softlockup_task); diff --git a/kernel/spinlock.c b/kernel/spinlock.c index ae28c82..29ab207 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -290,8 +290,8 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass) spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); } - EXPORT_SYMBOL(_spin_lock_nested); + unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) { unsigned long flags; @@ -311,9 +311,17 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas #endif return flags; } - EXPORT_SYMBOL(_spin_lock_irqsave_nested); +void __lockfunc _spin_lock_nest_lock(spinlock_t *lock, + struct lockdep_map *nest_lock) +{ + preempt_disable(); + spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_); + LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); +} +EXPORT_SYMBOL(_spin_lock_nest_lock); + #endif void __lockfunc _spin_unlock(spinlock_t *lock) @@ -436,7 +444,7 @@ int __lockfunc _spin_trylock_bh(spinlock_t *lock) } EXPORT_SYMBOL(_spin_trylock_bh); -int in_lock_functions(unsigned long addr) +notrace int in_lock_functions(unsigned long addr) { /* Linker adds these: start and end of __lockfunc functions */ extern char __lock_text_start[], __lock_text_end[]; diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index b71816e..94b527e 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -6,19 +6,21 @@ * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> */ #include <linux/sched.h> +#include <linux/module.h> #include <linux/kallsyms.h> #include <linux/stacktrace.h> void print_stack_trace(struct stack_trace *trace, int spaces) { - int i, j; + int i; - for (i = 0; i < trace->nr_entries; i++) { - unsigned long ip = trace->entries[i]; + if (WARN_ON(!trace->entries)) + return; - for (j = 0; j < spaces + 1; j++) - printk(" "); - print_ip_sym(ip); + for (i = 0; i < trace->nr_entries; i++) { + printk("%*c", 1 + spaces, ' '); + print_ip_sym(trace->entries[i]); } } +EXPORT_SYMBOL_GPL(print_stack_trace); diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index b7350bb..af3c7ce 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -1,4 +1,4 @@ -/* Copyright 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation. +/* Copyright 2008, 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation. * GPL v2 and any later version. */ #include <linux/cpu.h> @@ -13,203 +13,177 @@ #include <asm/atomic.h> #include <asm/uaccess.h> -/* Since we effect priority and affinity (both of which are visible - * to, and settable by outside processes) we do indirection via a - * kthread. */ - -/* Thread to stop each CPU in user context. */ +/* This controls the threads on each CPU. */ enum stopmachine_state { - STOPMACHINE_WAIT, + /* Dummy starting state for thread. */ + STOPMACHINE_NONE, + /* Awaiting everyone to be scheduled. */ STOPMACHINE_PREPARE, + /* Disable interrupts. */ STOPMACHINE_DISABLE_IRQ, + /* Run the function */ + STOPMACHINE_RUN, + /* Exit */ STOPMACHINE_EXIT, }; +static enum stopmachine_state state; -static enum stopmachine_state stopmachine_state; -static unsigned int stopmachine_num_threads; -static atomic_t stopmachine_thread_ack; - -static int stopmachine(void *cpu) -{ - int irqs_disabled = 0; - int prepared = 0; - - set_cpus_allowed_ptr(current, &cpumask_of_cpu((int)(long)cpu)); - - /* Ack: we are alive */ - smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */ - atomic_inc(&stopmachine_thread_ack); - - /* Simple state machine */ - while (stopmachine_state != STOPMACHINE_EXIT) { - if (stopmachine_state == STOPMACHINE_DISABLE_IRQ - && !irqs_disabled) { - local_irq_disable(); - hard_irq_disable(); - irqs_disabled = 1; - /* Ack: irqs disabled. */ - smp_mb(); /* Must read state first. */ - atomic_inc(&stopmachine_thread_ack); - } else if (stopmachine_state == STOPMACHINE_PREPARE - && !prepared) { - /* Everyone is in place, hold CPU. */ - preempt_disable(); - prepared = 1; - smp_mb(); /* Must read state first. */ - atomic_inc(&stopmachine_thread_ack); - } - /* Yield in first stage: migration threads need to - * help our sisters onto their CPUs. */ - if (!prepared && !irqs_disabled) - yield(); - cpu_relax(); - } - - /* Ack: we are exiting. */ - smp_mb(); /* Must read state first. */ - atomic_inc(&stopmachine_thread_ack); - - if (irqs_disabled) - local_irq_enable(); - if (prepared) - preempt_enable(); +struct stop_machine_data { + int (*fn)(void *); + void *data; + int fnret; +}; - return 0; -} +/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ +static unsigned int num_threads; +static atomic_t thread_ack; +static struct completion finished; +static DEFINE_MUTEX(lock); -/* Change the thread state */ -static void stopmachine_set_state(enum stopmachine_state state) +static void set_state(enum stopmachine_state newstate) { - atomic_set(&stopmachine_thread_ack, 0); + /* Reset ack counter. */ + atomic_set(&thread_ack, num_threads); smp_wmb(); - stopmachine_state = state; - while (atomic_read(&stopmachine_thread_ack) != stopmachine_num_threads) - cpu_relax(); + state = newstate; } -static int stop_machine(void) +/* Last one to ack a state moves to the next state. */ +static void ack_state(void) { - int i, ret = 0; - - atomic_set(&stopmachine_thread_ack, 0); - stopmachine_num_threads = 0; - stopmachine_state = STOPMACHINE_WAIT; - - for_each_online_cpu(i) { - if (i == raw_smp_processor_id()) - continue; - ret = kernel_thread(stopmachine, (void *)(long)i,CLONE_KERNEL); - if (ret < 0) - break; - stopmachine_num_threads++; - } - - /* Wait for them all to come to life. */ - while (atomic_read(&stopmachine_thread_ack) != stopmachine_num_threads) { - yield(); - cpu_relax(); + if (atomic_dec_and_test(&thread_ack)) { + /* If we're the last one to ack the EXIT, we're finished. */ + if (state == STOPMACHINE_EXIT) + complete(&finished); + else + set_state(state + 1); } +} - /* If some failed, kill them all. */ - if (ret < 0) { - stopmachine_set_state(STOPMACHINE_EXIT); - return ret; - } +/* This is the actual thread which stops the CPU. It exits by itself rather + * than waiting for kthread_stop(), because it's easier for hotplug CPU. */ +static int stop_cpu(struct stop_machine_data *smdata) +{ + enum stopmachine_state curstate = STOPMACHINE_NONE; - /* Now they are all started, make them hold the CPUs, ready. */ - preempt_disable(); - stopmachine_set_state(STOPMACHINE_PREPARE); + /* Simple state machine */ + do { + /* Chill out and ensure we re-read stopmachine_state. */ + cpu_relax(); + if (state != curstate) { + curstate = state; + switch (curstate) { + case STOPMACHINE_DISABLE_IRQ: + local_irq_disable(); + hard_irq_disable(); + break; + case STOPMACHINE_RUN: + /* |= allows error detection if functions on + * multiple CPUs. */ + smdata->fnret |= smdata->fn(smdata->data); + break; + default: + break; + } + ack_state(); + } + } while (curstate != STOPMACHINE_EXIT); - /* Make them disable irqs. */ - local_irq_disable(); - hard_irq_disable(); - stopmachine_set_state(STOPMACHINE_DISABLE_IRQ); + local_irq_enable(); + do_exit(0); +} +/* Callback for CPUs which aren't supposed to do anything. */ +static int chill(void *unused) +{ return 0; } -static void restart_machine(void) +int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { - stopmachine_set_state(STOPMACHINE_EXIT); - local_irq_enable(); - preempt_enable_no_resched(); -} + int i, err; + struct stop_machine_data active, idle; + struct task_struct **threads; + + active.fn = fn; + active.data = data; + active.fnret = 0; + idle.fn = chill; + idle.data = NULL; + + /* This could be too big for stack on large machines. */ + threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL); + if (!threads) + return -ENOMEM; + + /* Set up initial state. */ + mutex_lock(&lock); + init_completion(&finished); + num_threads = num_online_cpus(); + set_state(STOPMACHINE_PREPARE); -struct stop_machine_data { - int (*fn)(void *); - void *data; - struct completion done; -}; + for_each_online_cpu(i) { + struct stop_machine_data *smdata = &idle; + struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; -static int do_stop(void *_smdata) -{ - struct stop_machine_data *smdata = _smdata; - int ret; + if (!cpus) { + if (i == first_cpu(cpu_online_map)) + smdata = &active; + } else { + if (cpu_isset(i, *cpus)) + smdata = &active; + } - ret = stop_machine(); - if (ret == 0) { - ret = smdata->fn(smdata->data); - restart_machine(); - } + threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u", + i); + if (IS_ERR(threads[i])) { + err = PTR_ERR(threads[i]); + threads[i] = NULL; + goto kill_threads; + } - /* We're done: you can kthread_stop us now */ - complete(&smdata->done); + /* Place it onto correct cpu. */ + kthread_bind(threads[i], i); - /* Wait for kthread_stop */ - set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) { - schedule(); - set_current_state(TASK_INTERRUPTIBLE); + /* Make it highest prio. */ + if (sched_setscheduler_nocheck(threads[i], SCHED_FIFO, ¶m)) + BUG(); } - __set_current_state(TASK_RUNNING); - return ret; -} -struct task_struct *__stop_machine_run(int (*fn)(void *), void *data, - unsigned int cpu) -{ - static DEFINE_MUTEX(stopmachine_mutex); - struct stop_machine_data smdata; - struct task_struct *p; + /* We've created all the threads. Wake them all: hold this CPU so one + * doesn't hit this CPU until we're ready. */ + get_cpu(); + for_each_online_cpu(i) + wake_up_process(threads[i]); - smdata.fn = fn; - smdata.data = data; - init_completion(&smdata.done); + /* This will release the thread on our CPU. */ + put_cpu(); + wait_for_completion(&finished); + mutex_unlock(&lock); - mutex_lock(&stopmachine_mutex); + kfree(threads); - /* If they don't care which CPU fn runs on, bind to any online one. */ - if (cpu == NR_CPUS) - cpu = raw_smp_processor_id(); + return active.fnret; - p = kthread_create(do_stop, &smdata, "kstopmachine"); - if (!IS_ERR(p)) { - struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; +kill_threads: + for_each_online_cpu(i) + if (threads[i]) + kthread_stop(threads[i]); + mutex_unlock(&lock); - /* One high-prio thread per cpu. We'll do this one. */ - sched_setscheduler(p, SCHED_FIFO, ¶m); - kthread_bind(p, cpu); - wake_up_process(p); - wait_for_completion(&smdata.done); - } - mutex_unlock(&stopmachine_mutex); - return p; + kfree(threads); + return err; } -int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) +int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { - struct task_struct *p; int ret; /* No CPUs can come up or down during this. */ get_online_cpus(); - p = __stop_machine_run(fn, data, cpu); - if (!IS_ERR(p)) - ret = kthread_stop(p); - else - ret = PTR_ERR(p); + ret = __stop_machine(fn, data, cpus); put_online_cpus(); return ret; } -EXPORT_SYMBOL_GPL(stop_machine_run); +EXPORT_SYMBOL_GPL(stop_machine); diff --git a/kernel/sys.c b/kernel/sys.c index 14e9728..234d945 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -169,9 +169,9 @@ asmlinkage long sys_setpriority(int which, int who, int niceval) pgrp = find_vpid(who); else pgrp = task_pgrp(current); - do_each_pid_task(pgrp, PIDTYPE_PGID, p) { + do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { error = set_one_prio(p, niceval, error); - } while_each_pid_task(pgrp, PIDTYPE_PGID, p); + } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: user = current->user; @@ -229,11 +229,11 @@ asmlinkage long sys_getpriority(int which, int who) pgrp = find_vpid(who); else pgrp = task_pgrp(current); - do_each_pid_task(pgrp, PIDTYPE_PGID, p) { + do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; - } while_each_pid_task(pgrp, PIDTYPE_PGID, p); + } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: user = current->user; @@ -274,7 +274,7 @@ void emergency_restart(void) } EXPORT_SYMBOL_GPL(emergency_restart); -static void kernel_restart_prepare(char *cmd) +void kernel_restart_prepare(char *cmd) { blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; @@ -301,26 +301,6 @@ void kernel_restart(char *cmd) } EXPORT_SYMBOL_GPL(kernel_restart); -/** - * kernel_kexec - reboot the system - * - * Move into place and start executing a preloaded standalone - * executable. If nothing was preloaded return an error. - */ -static void kernel_kexec(void) -{ -#ifdef CONFIG_KEXEC - struct kimage *image; - image = xchg(&kexec_image, NULL); - if (!image) - return; - kernel_restart_prepare(NULL); - printk(KERN_EMERG "Starting new kernel\n"); - machine_shutdown(); - machine_kexec(image); -#endif -} - static void kernel_shutdown_prepare(enum system_states state) { blocking_notifier_call_chain(&reboot_notifier_list, @@ -425,10 +405,15 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user kernel_restart(buffer); break; +#ifdef CONFIG_KEXEC case LINUX_REBOOT_CMD_KEXEC: - kernel_kexec(); - unlock_kernel(); - return -EINVAL; + { + int ret; + ret = kernel_kexec(); + unlock_kernel(); + return ret; + } +#endif #ifdef CONFIG_HIBERNATION case LINUX_REBOOT_CMD_SW_SUSPEND: @@ -1075,9 +1060,7 @@ asmlinkage long sys_setsid(void) group_leader->signal->leader = 1; __set_special_pids(sid); - spin_lock(&group_leader->sighand->siglock); - group_leader->signal->tty = NULL; - spin_unlock(&group_leader->sighand->siglock); + proc_clear_tty(group_leader); err = session; out: @@ -1343,8 +1326,6 @@ EXPORT_SYMBOL(in_egroup_p); DECLARE_RWSEM(uts_sem); -EXPORT_SYMBOL(uts_sem); - asmlinkage long sys_newuname(struct new_utsname __user * name) { int errno = 0; @@ -1795,7 +1776,7 @@ int orderly_poweroff(bool force) goto out; } - info = call_usermodehelper_setup(argv[0], argv, envp); + info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); if (info == NULL) { argv_free(argv); goto out; diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 5b9b467..503d8d4 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -31,6 +31,7 @@ cond_syscall(sys_socketpair); cond_syscall(sys_bind); cond_syscall(sys_listen); cond_syscall(sys_accept); +cond_syscall(sys_paccept); cond_syscall(sys_connect); cond_syscall(sys_getsockname); cond_syscall(sys_getpeername); @@ -56,9 +57,11 @@ cond_syscall(compat_sys_set_robust_list); cond_syscall(sys_get_robust_list); cond_syscall(compat_sys_get_robust_list); cond_syscall(sys_epoll_create); +cond_syscall(sys_epoll_create1); cond_syscall(sys_epoll_ctl); cond_syscall(sys_epoll_wait); cond_syscall(sys_epoll_pwait); +cond_syscall(compat_sys_epoll_pwait); cond_syscall(sys_semget); cond_syscall(sys_semop); cond_syscall(sys_semtimedop); @@ -94,6 +97,7 @@ cond_syscall(sys_keyctl); cond_syscall(compat_sys_keyctl); cond_syscall(compat_sys_socketcall); cond_syscall(sys_inotify_init); +cond_syscall(sys_inotify_init1); cond_syscall(sys_inotify_add_watch); cond_syscall(sys_inotify_rm_watch); cond_syscall(sys_migrate_pages); @@ -121,6 +125,7 @@ cond_syscall(sys_vm86old); cond_syscall(sys_vm86); cond_syscall(compat_sys_ipc); cond_syscall(compat_sys_sysctl); +cond_syscall(sys_flock); /* arch-specific weak syscall entries */ cond_syscall(sys_pciconfig_read); @@ -154,10 +159,13 @@ cond_syscall(sys_ioprio_get); /* New file descriptors */ cond_syscall(sys_signalfd); +cond_syscall(sys_signalfd4); cond_syscall(compat_sys_signalfd); +cond_syscall(compat_sys_signalfd4); cond_syscall(sys_timerfd_create); cond_syscall(sys_timerfd_settime); cond_syscall(sys_timerfd_gettime); cond_syscall(compat_sys_timerfd_settime); cond_syscall(compat_sys_timerfd_gettime); cond_syscall(sys_eventfd); +cond_syscall(sys_eventfd2); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2911665..cfc5295 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -43,9 +43,11 @@ #include <linux/limits.h> #include <linux/dcache.h> #include <linux/syscalls.h> +#include <linux/vmstat.h> #include <linux/nfs_fs.h> #include <linux/acpi.h> #include <linux/reboot.h> +#include <linux/ftrace.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -78,21 +80,23 @@ extern int pid_max_min, pid_max_max; extern int sysctl_drop_caches; extern int percpu_pagelist_fraction; extern int compat_log; -extern int maps_protect; -extern int sysctl_stat_interval; extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; +#ifdef CONFIG_RCU_TORTURE_TEST +extern int rcutorture_runnable; +#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */ /* Constants used for minimum and maximum */ -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP) static int one = 1; #endif #ifdef CONFIG_DETECT_SOFTLOCKUP static int sixty = 60; +static int neg_one = -1; #endif -#ifdef CONFIG_MMU +#if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING) static int two = 2; #endif @@ -106,17 +110,15 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES extern char modprobe_path[]; #endif #ifdef CONFIG_CHR_DEV_SG extern int sg_big_buff; #endif -#ifdef __sparc__ -extern char reboot_command []; -extern int stop_a_enabled; -extern int scons_pwroff; +#ifdef CONFIG_SPARC +#include <asm/system.h> #endif #ifdef __hppa__ @@ -132,8 +134,6 @@ extern int sysctl_userprocess_debug; extern int spin_retry; #endif -extern int sysctl_hz_timer; - #ifdef CONFIG_BSD_PROCESS_ACCT extern int acct_parm[]; #endif @@ -156,13 +156,15 @@ static int proc_dointvec_taint(struct ctl_table *table, int write, struct file * static struct ctl_table root_table[]; static struct ctl_table_root sysctl_table_root; static struct ctl_table_header root_table_header = { + .count = 1, .ctl_table = root_table, - .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list), + .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list), .root = &sysctl_table_root, + .set = &sysctl_table_root.default_set, }; static struct ctl_table_root sysctl_table_root = { .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), - .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry), + .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), }; static struct ctl_table kern_table[]; @@ -266,6 +268,14 @@ static struct ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, + .procname = "sched_shares_ratelimit", + .data = &sysctl_sched_shares_ratelimit, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "sched_child_runs_first", .data = &sysctl_sched_child_runs_first, .maxlen = sizeof(unsigned int), @@ -402,7 +412,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, -#ifdef __sparc__ +#ifdef CONFIG_SPARC { .ctl_name = KERN_SPARC_REBOOT, .procname = "reboot-cmd", @@ -455,7 +465,17 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, -#ifdef CONFIG_KMOD +#ifdef CONFIG_FTRACE + { + .ctl_name = CTL_UNNUMBERED, + .procname = "ftrace_enabled", + .data = &ftrace_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &ftrace_enable_sysctl, + }, +#endif +#ifdef CONFIG_MODULES { .ctl_name = KERN_MODPROBE, .procname = "modprobe", @@ -563,16 +583,6 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif -#ifdef CONFIG_NO_IDLE_HZ - { - .ctl_name = KERN_HZ_TIMER, - .procname = "hz_timer", - .data = &sysctl_hz_timer, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, -#endif { .ctl_name = KERN_S390_USER_DEBUG_LOGGING, .procname = "userprocess_debug", @@ -613,7 +623,7 @@ static struct ctl_table kern_table[] = { { .ctl_name = KERN_PRINTK_RATELIMIT, .procname = "printk_ratelimit", - .data = &printk_ratelimit_jiffies, + .data = &printk_ratelimit_state.interval, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec_jiffies, @@ -622,7 +632,7 @@ static struct ctl_table kern_table[] = { { .ctl_name = KERN_PRINTK_RATELIMIT_BURST, .procname = "printk_ratelimit_burst", - .data = &printk_ratelimit_burst, + .data = &printk_ratelimit_state.burst, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec, @@ -729,13 +739,24 @@ static struct ctl_table kern_table[] = { #ifdef CONFIG_DETECT_SOFTLOCKUP { .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_panic", + .data = &softlockup_panic, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", .data = &softlockup_thresh, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, - .extra1 = &one, + .extra1 = &neg_one, .extra2 = &sixty, }, { @@ -786,16 +807,6 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif -#ifdef CONFIG_PROC_FS - { - .ctl_name = CTL_UNNUMBERED, - .procname = "maps_protect", - .data = &maps_protect, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, -#endif { .ctl_name = CTL_UNNUMBERED, .procname = "poweroff_cmd", @@ -813,6 +824,16 @@ static struct ctl_table kern_table[] = { .child = key_sysctls, }, #endif +#ifdef CONFIG_RCU_TORTURE_TEST + { + .ctl_name = CTL_UNNUMBERED, + .procname = "rcutorture_runnable", + .data = &rcutorture_runnable, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, +#endif /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt @@ -927,7 +948,7 @@ static struct ctl_table vm_table[] = { #ifdef CONFIG_HUGETLB_PAGE { .procname = "nr_hugepages", - .data = &max_huge_pages, + .data = NULL, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &hugetlb_sysctl_handler, @@ -953,10 +974,12 @@ static struct ctl_table vm_table[] = { { .ctl_name = CTL_UNNUMBERED, .procname = "nr_overcommit_hugepages", - .data = &sysctl_overcommit_huge_pages, - .maxlen = sizeof(sysctl_overcommit_huge_pages), + .data = NULL, + .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &hugetlb_overcommit_handler, + .extra1 = (void *)&hugetlb_zero, + .extra2 = (void *)&hugetlb_infinity, }, #endif { @@ -1225,6 +1248,7 @@ static struct ctl_table fs_table[] = { .extra1 = &minolduid, .extra2 = &maxolduid, }, +#ifdef CONFIG_FILE_LOCKING { .ctl_name = FS_LEASES, .procname = "leases-enable", @@ -1233,6 +1257,7 @@ static struct ctl_table fs_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, +#endif #ifdef CONFIG_DNOTIFY { .ctl_name = FS_DIR_NOTIFY, @@ -1244,6 +1269,7 @@ static struct ctl_table fs_table[] = { }, #endif #ifdef CONFIG_MMU +#ifdef CONFIG_FILE_LOCKING { .ctl_name = FS_LEASE_TIME, .procname = "lease-break-time", @@ -1255,6 +1281,7 @@ static struct ctl_table fs_table[] = { .extra1 = &zero, .extra2 = &two, }, +#endif { .procname = "aio-nr", .data = &aio_nr, @@ -1352,6 +1379,9 @@ static void start_unregistering(struct ctl_table_header *p) spin_unlock(&sysctl_lock); wait_for_completion(&wait); spin_lock(&sysctl_lock); + } else { + /* anything non-NULL; we'll never dereference it */ + p->unregistering = ERR_PTR(-EINVAL); } /* * do not remove from the list until nobody holds it; walking the @@ -1360,6 +1390,32 @@ static void start_unregistering(struct ctl_table_header *p) list_del_init(&p->ctl_entry); } +void sysctl_head_get(struct ctl_table_header *head) +{ + spin_lock(&sysctl_lock); + head->count++; + spin_unlock(&sysctl_lock); +} + +void sysctl_head_put(struct ctl_table_header *head) +{ + spin_lock(&sysctl_lock); + if (!--head->count) + kfree(head); + spin_unlock(&sysctl_lock); +} + +struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) +{ + if (!head) + BUG(); + spin_lock(&sysctl_lock); + if (!use_table(head)) + head = ERR_PTR(-ENOENT); + spin_unlock(&sysctl_lock); + return head; +} + void sysctl_head_finish(struct ctl_table_header *head) { if (!head) @@ -1369,14 +1425,20 @@ void sysctl_head_finish(struct ctl_table_header *head) spin_unlock(&sysctl_lock); } +static struct ctl_table_set * +lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) +{ + struct ctl_table_set *set = &root->default_set; + if (root->lookup) + set = root->lookup(root, namespaces); + return set; +} + static struct list_head * lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) { - struct list_head *header_list; - header_list = &root->header_list; - if (root->lookup) - header_list = root->lookup(root, namespaces); - return header_list; + struct ctl_table_set *set = lookup_header_set(root, namespaces); + return &set->list; } struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, @@ -1446,9 +1508,9 @@ static int do_sysctl_strategy(struct ctl_table_root *root, int op = 0, rc; if (oldval) - op |= 004; + op |= MAY_READ; if (newval) - op |= 002; + op |= MAY_WRITE; if (sysctl_perm(root, table, op)) return -EPERM; @@ -1490,7 +1552,7 @@ repeat: if (n == table->ctl_name) { int error; if (table->child) { - if (sysctl_perm(root, table, 001)) + if (sysctl_perm(root, table, MAY_EXEC)) return -EPERM; name++; nlen--; @@ -1565,7 +1627,7 @@ static int test_perm(int mode, int op) mode >>= 6; else if (in_egroup_p(0)) mode >>= 3; - if ((mode & op & 0007) == op) + if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) return 0; return -EACCES; } @@ -1575,7 +1637,7 @@ int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) int error; int mode; - error = security_sysctl(table, op); + error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC)); if (error) return error; @@ -1610,6 +1672,54 @@ static __init int sysctl_init(void) core_initcall(sysctl_init); +static struct ctl_table *is_branch_in(struct ctl_table *branch, + struct ctl_table *table) +{ + struct ctl_table *p; + const char *s = branch->procname; + + /* branch should have named subdirectory as its first element */ + if (!s || !branch->child) + return NULL; + + /* ... and nothing else */ + if (branch[1].procname || branch[1].ctl_name) + return NULL; + + /* table should contain subdirectory with the same name */ + for (p = table; p->procname || p->ctl_name; p++) { + if (!p->child) + continue; + if (p->procname && strcmp(p->procname, s) == 0) + return p; + } + return NULL; +} + +/* see if attaching q to p would be an improvement */ +static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) +{ + struct ctl_table *to = p->ctl_table, *by = q->ctl_table; + struct ctl_table *next; + int is_better = 0; + int not_in_parent = !p->attached_by; + + while ((next = is_branch_in(by, to)) != NULL) { + if (by == q->attached_by) + is_better = 1; + if (to == p->attached_by) + not_in_parent = 1; + by = by->child; + to = next->child; + } + + if (is_better && not_in_parent) { + q->attached_by = by; + q->attached_to = to; + q->parent = p; + } +} + /** * __register_sysctl_paths - register a sysctl hierarchy * @root: List of sysctl headers to register on @@ -1686,10 +1796,10 @@ struct ctl_table_header *__register_sysctl_paths( struct nsproxy *namespaces, const struct ctl_path *path, struct ctl_table *table) { - struct list_head *header_list; struct ctl_table_header *header; struct ctl_table *new, **prevp; unsigned int n, npath; + struct ctl_table_set *set; /* Count the path components */ for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath) @@ -1731,6 +1841,7 @@ struct ctl_table_header *__register_sysctl_paths( header->unregistering = NULL; header->root = root; sysctl_set_parent(NULL, header->ctl_table); + header->count = 1; #ifdef CONFIG_SYSCTL_SYSCALL_CHECK if (sysctl_check_table(namespaces, header->ctl_table)) { kfree(header); @@ -1738,8 +1849,20 @@ struct ctl_table_header *__register_sysctl_paths( } #endif spin_lock(&sysctl_lock); - header_list = lookup_header_list(root, namespaces); - list_add_tail(&header->ctl_entry, header_list); + header->set = lookup_header_set(root, namespaces); + header->attached_by = header->ctl_table; + header->attached_to = root_table; + header->parent = &root_table_header; + for (set = header->set; set; set = set->parent) { + struct ctl_table_header *p; + list_for_each_entry(p, &set->list, ctl_entry) { + if (p->unregistering) + continue; + try_attach(p, header); + } + } + header->parent->count++; + list_add_tail(&header->ctl_entry, &header->set->list); spin_unlock(&sysctl_lock); return header; @@ -1794,8 +1917,37 @@ void unregister_sysctl_table(struct ctl_table_header * header) spin_lock(&sysctl_lock); start_unregistering(header); + if (!--header->parent->count) { + WARN_ON(1); + kfree(header->parent); + } + if (!--header->count) + kfree(header); spin_unlock(&sysctl_lock); - kfree(header); +} + +int sysctl_is_seen(struct ctl_table_header *p) +{ + struct ctl_table_set *set = p->set; + int res; + spin_lock(&sysctl_lock); + if (p->unregistering) + res = 0; + else if (!set->is_seen) + res = 1; + else + res = set->is_seen(set); + spin_unlock(&sysctl_lock); + return res; +} + +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ + INIT_LIST_HEAD(&p->list); + p->parent = parent ? parent : &sysctl_table_root.default_set; + p->is_seen = is_seen; } #else /* !CONFIG_SYSCTL */ @@ -1814,6 +1966,16 @@ void unregister_sysctl_table(struct ctl_table_header * table) { } +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ +} + +void sysctl_head_put(struct ctl_table_header *head) +{ +} + #endif /* CONFIG_SYSCTL */ /* diff --git a/kernel/sysctl_check.c b/kernel/sysctl_check.c index c09350d..c35da23a 100644 --- a/kernel/sysctl_check.c +++ b/kernel/sysctl_check.c @@ -1532,6 +1532,8 @@ int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table) sysctl_check_leaf(namespaces, table, &fail); } sysctl_check_bin_path(table, &fail); + if (table->mode > 0777) + set_fail(&fail, table, "bogus .mode"); if (fail) { set_fail(&fail, table, NULL); error = -EINVAL; diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 4a23517..bd6be76 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -35,7 +35,7 @@ */ #define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS) -static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; +static DEFINE_PER_CPU(__u32, taskstats_seqnum); static int family_registered; struct kmem_cache *taskstats_cache; @@ -301,7 +301,7 @@ static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) return -EINVAL; if (isadd == REGISTER) { - for_each_cpu_mask(cpu, mask) { + for_each_cpu_mask_nr(cpu, mask) { s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, cpu_to_node(cpu)); if (!s) @@ -320,7 +320,7 @@ static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) /* Deregister or cleanup */ cleanup: - for_each_cpu_mask(cpu, mask) { + for_each_cpu_mask_nr(cpu, mask) { listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); list_for_each_entry_safe(s, tmp, &listeners->list, list) { diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 3d1e3e1..f8d9680 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -72,6 +72,16 @@ void clockevents_set_mode(struct clock_event_device *dev, } /** + * clockevents_shutdown - shutdown the device and clear next_event + * @dev: device to shutdown + */ +void clockevents_shutdown(struct clock_event_device *dev) +{ + clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); + dev->next_event.tv64 = KTIME_MAX; +} + +/** * clockevents_program_event - Reprogram the clock event device. * @expires: absolute expiry time (monotonic clock) * @@ -177,7 +187,7 @@ void clockevents_register_device(struct clock_event_device *dev) /* * Noop handler when we shut down an event device */ -static void clockevents_handle_noop(struct clock_event_device *dev) +void clockevents_handle_noop(struct clock_event_device *dev) { } @@ -199,7 +209,6 @@ void clockevents_exchange_device(struct clock_event_device *old, * released list and do a notify add later. */ if (old) { - old->event_handler = clockevents_handle_noop; clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); list_del(&old->list); list_add(&old->list, &clockevents_released); @@ -207,7 +216,7 @@ void clockevents_exchange_device(struct clock_event_device *old, if (new) { BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED); - clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_shutdown(new); } local_irq_restore(flags); } diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index dadde53..093d4ac 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -145,9 +145,9 @@ static void clocksource_watchdog(unsigned long data) * Cycle through CPUs to check if the CPUs stay * synchronized to each other. */ - int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map); + int next_cpu = next_cpu_nr(raw_smp_processor_id(), cpu_online_map); - if (next_cpu >= NR_CPUS) + if (next_cpu >= nr_cpu_ids) next_cpu = first_cpu(cpu_online_map); watchdog_timer.expires += WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, next_cpu); @@ -376,7 +376,8 @@ void clocksource_unregister(struct clocksource *cs) * Provides sysfs interface for listing current clocksource. */ static ssize_t -sysfs_show_current_clocksources(struct sys_device *dev, char *buf) +sysfs_show_current_clocksources(struct sys_device *dev, + struct sysdev_attribute *attr, char *buf) { ssize_t count = 0; @@ -397,6 +398,7 @@ sysfs_show_current_clocksources(struct sys_device *dev, char *buf) * clocksource selction. */ static ssize_t sysfs_override_clocksource(struct sys_device *dev, + struct sysdev_attribute *attr, const char *buf, size_t count) { struct clocksource *ovr = NULL; @@ -449,7 +451,9 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, * Provides sysfs interface for listing registered clocksources */ static ssize_t -sysfs_show_available_clocksources(struct sys_device *dev, char *buf) +sysfs_show_available_clocksources(struct sys_device *dev, + struct sysdev_attribute *attr, + char *buf) { struct clocksource *src; ssize_t count = 0; diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 5125ddd..1ad46f3 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -245,7 +245,7 @@ static void sync_cmos_clock(unsigned long dummy) if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) fail = update_persistent_clock(now); - next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec; + next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2); if (next.tv_nsec <= 0) next.tv_nsec += NSEC_PER_SEC; diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 57a1f02..cb01cd8 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -30,6 +30,7 @@ struct tick_device tick_broadcast_device; static cpumask_t tick_broadcast_mask; static DEFINE_SPINLOCK(tick_broadcast_lock); +static int tick_broadcast_force; #ifdef CONFIG_TICK_ONESHOT static void tick_broadcast_clear_oneshot(int cpu); @@ -174,6 +175,8 @@ static void tick_do_periodic_broadcast(void) */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { + ktime_t next; + tick_do_periodic_broadcast(); /* @@ -184,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) /* * Setup the next period for devices, which do not have - * periodic mode: + * periodic mode. We read dev->next_event first and add to it + * when the event alrady expired. clockevents_program_event() + * sets dev->next_event only when the event is really + * programmed to the device. */ - for (;;) { - ktime_t next = ktime_add(dev->next_event, tick_period); + for (next = dev->next_event; ;) { + next = ktime_add(next, tick_period); if (!clockevents_program_event(dev, next, ktime_get())) return; @@ -204,7 +210,7 @@ static void tick_do_broadcast_on_off(void *why) struct clock_event_device *bc, *dev; struct tick_device *td; unsigned long flags, *reason = why; - int cpu; + int cpu, bc_stopped; spin_lock_irqsave(&tick_broadcast_lock, flags); @@ -222,30 +228,35 @@ static void tick_do_broadcast_on_off(void *why) if (!tick_device_is_functional(dev)) goto out; + bc_stopped = cpus_empty(tick_broadcast_mask); + switch (*reason) { case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: if (!cpu_isset(cpu, tick_broadcast_mask)) { cpu_set(cpu, tick_broadcast_mask); - if (td->mode == TICKDEV_MODE_PERIODIC) - clockevents_set_mode(dev, - CLOCK_EVT_MODE_SHUTDOWN); + if (tick_broadcast_device.mode == + TICKDEV_MODE_PERIODIC) + clockevents_shutdown(dev); } if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE) - dev->features |= CLOCK_EVT_FEAT_DUMMY; + tick_broadcast_force = 1; break; case CLOCK_EVT_NOTIFY_BROADCAST_OFF: - if (cpu_isset(cpu, tick_broadcast_mask)) { + if (!tick_broadcast_force && + cpu_isset(cpu, tick_broadcast_mask)) { cpu_clear(cpu, tick_broadcast_mask); - if (td->mode == TICKDEV_MODE_PERIODIC) + if (tick_broadcast_device.mode == + TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } break; } - if (cpus_empty(tick_broadcast_mask)) - clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN); - else { + if (cpus_empty(tick_broadcast_mask)) { + if (!bc_stopped) + clockevents_shutdown(bc); + } else if (bc_stopped) { if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) tick_broadcast_start_periodic(bc); else @@ -266,7 +277,7 @@ void tick_broadcast_on_off(unsigned long reason, int *oncpu) "offline CPU #%d\n", *oncpu); else smp_call_function_single(*oncpu, tick_do_broadcast_on_off, - &reason, 1, 1); + &reason, 1); } /* @@ -296,7 +307,7 @@ void tick_shutdown_broadcast(unsigned int *cpup) if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) { if (bc && cpus_empty(tick_broadcast_mask)) - clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_shutdown(bc); } spin_unlock_irqrestore(&tick_broadcast_lock, flags); @@ -311,7 +322,7 @@ void tick_suspend_broadcast(void) bc = tick_broadcast_device.evtdev; if (bc) - clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_shutdown(bc); spin_unlock_irqrestore(&tick_broadcast_lock, flags); } @@ -362,16 +373,8 @@ cpumask_t *tick_get_broadcast_oneshot_mask(void) static int tick_broadcast_set_event(ktime_t expires, int force) { struct clock_event_device *bc = tick_broadcast_device.evtdev; - ktime_t now = ktime_get(); - int res; - - for(;;) { - res = clockevents_program_event(bc, expires, now); - if (!res || !force) - return res; - now = ktime_get(); - expires = ktime_add(now, ktime_set(0, bc->min_delta_ns)); - } + + return tick_dev_program_event(bc, expires, force); } int tick_resume_broadcast_oneshot(struct clock_event_device *bc) @@ -397,8 +400,7 @@ again: mask = CPU_MASK_NONE; now = ktime_get(); /* Find all expired events */ - for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS; - cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) { + for_each_cpu_mask_nr(cpu, tick_broadcast_oneshot_mask) { td = &per_cpu(tick_cpu_device, cpu); if (td->evtdev->next_event.tv64 <= now.tv64) cpu_set(cpu, mask); @@ -490,14 +492,52 @@ static void tick_broadcast_clear_oneshot(int cpu) cpu_clear(cpu, tick_broadcast_oneshot_mask); } +static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires) +{ + struct tick_device *td; + int cpu; + + for_each_cpu_mask_nr(cpu, *mask) { + td = &per_cpu(tick_cpu_device, cpu); + if (td->evtdev) + td->evtdev->next_event = expires; + } +} + /** * tick_broadcast_setup_oneshot - setup the broadcast device */ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { - bc->event_handler = tick_handle_oneshot_broadcast; - clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); - bc->next_event.tv64 = KTIME_MAX; + /* Set it up only once ! */ + if (bc->event_handler != tick_handle_oneshot_broadcast) { + int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC; + int cpu = smp_processor_id(); + cpumask_t mask; + + bc->event_handler = tick_handle_oneshot_broadcast; + clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); + + /* Take the do_timer update */ + tick_do_timer_cpu = cpu; + + /* + * We must be careful here. There might be other CPUs + * waiting for periodic broadcast. We need to set the + * oneshot_mask bits for those and program the + * broadcast device to fire. + */ + mask = tick_broadcast_mask; + cpu_clear(cpu, mask); + cpus_or(tick_broadcast_oneshot_mask, + tick_broadcast_oneshot_mask, mask); + + if (was_periodic && !cpus_empty(mask)) { + tick_broadcast_init_next_event(&mask, tick_next_period); + tick_broadcast_set_event(tick_next_period, 1); + } else + bc->next_event.tv64 = KTIME_MAX; + } } /* @@ -537,4 +577,12 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup) spin_unlock_irqrestore(&tick_broadcast_lock, flags); } +/* + * Check, whether the broadcast device is in one shot mode + */ +int tick_broadcast_oneshot_active(void) +{ + return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT; +} + #endif diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 4f38865..df12434 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -33,7 +33,7 @@ DEFINE_PER_CPU(struct tick_device, tick_cpu_device); */ ktime_t tick_next_period; ktime_t tick_period; -int tick_do_timer_cpu __read_mostly = -1; +int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT; DEFINE_SPINLOCK(tick_device_lock); /* @@ -109,7 +109,8 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast) if (!tick_device_is_functional(dev)) return; - if (dev->features & CLOCK_EVT_FEAT_PERIODIC) { + if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) && + !tick_broadcast_oneshot_active()) { clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC); } else { unsigned long seq; @@ -135,7 +136,7 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast) */ static void tick_setup_device(struct tick_device *td, struct clock_event_device *newdev, int cpu, - cpumask_t cpumask) + const cpumask_t *cpumask) { ktime_t next_event; void (*handler)(struct clock_event_device *) = NULL; @@ -148,7 +149,7 @@ static void tick_setup_device(struct tick_device *td, * If no cpu took the do_timer update, assign it to * this cpu: */ - if (tick_do_timer_cpu == -1) { + if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) { tick_do_timer_cpu = cpu; tick_next_period = ktime_get(); tick_period = ktime_set(0, NSEC_PER_SEC / HZ); @@ -161,6 +162,7 @@ static void tick_setup_device(struct tick_device *td, } else { handler = td->evtdev->event_handler; next_event = td->evtdev->next_event; + td->evtdev->event_handler = clockevents_handle_noop; } td->evtdev = newdev; @@ -169,8 +171,8 @@ static void tick_setup_device(struct tick_device *td, * When the device is not per cpu, pin the interrupt to the * current cpu: */ - if (!cpus_equal(newdev->cpumask, cpumask)) - irq_set_affinity(newdev->irq, cpumask); + if (!cpus_equal(newdev->cpumask, *cpumask)) + irq_set_affinity(newdev->irq, *cpumask); /* * When global broadcasting is active, check if the current @@ -196,7 +198,6 @@ static int tick_check_new_device(struct clock_event_device *newdev) struct tick_device *td; int cpu, ret = NOTIFY_OK; unsigned long flags; - cpumask_t cpumask; spin_lock_irqsave(&tick_device_lock, flags); @@ -206,10 +207,9 @@ static int tick_check_new_device(struct clock_event_device *newdev) td = &per_cpu(tick_cpu_device, cpu); curdev = td->evtdev; - cpumask = cpumask_of_cpu(cpu); /* cpu local device ? */ - if (!cpus_equal(newdev->cpumask, cpumask)) { + if (!cpus_equal(newdev->cpumask, cpumask_of_cpu(cpu))) { /* * If the cpu affinity of the device interrupt can not @@ -222,7 +222,7 @@ static int tick_check_new_device(struct clock_event_device *newdev) * If we have a cpu local device already, do not replace it * by a non cpu local device */ - if (curdev && cpus_equal(curdev->cpumask, cpumask)) + if (curdev && cpus_equal(curdev->cpumask, cpumask_of_cpu(cpu))) goto out_bc; } @@ -250,11 +250,11 @@ static int tick_check_new_device(struct clock_event_device *newdev) * not give it back to the clockevents layer ! */ if (tick_is_broadcast_device(curdev)) { - clockevents_set_mode(curdev, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_shutdown(curdev); curdev = NULL; } clockevents_exchange_device(curdev, newdev); - tick_setup_device(td, newdev, cpu, cpumask); + tick_setup_device(td, newdev, cpu, &cpumask_of_cpu(cpu)); if (newdev->features & CLOCK_EVT_FEAT_ONESHOT) tick_oneshot_notify(); @@ -301,7 +301,8 @@ static void tick_shutdown(unsigned int *cpup) if (*cpup == tick_do_timer_cpu) { int cpu = first_cpu(cpu_online_map); - tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu : -1; + tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu : + TICK_DO_TIMER_NONE; } spin_unlock_irqrestore(&tick_device_lock, flags); } @@ -312,7 +313,7 @@ static void tick_suspend(void) unsigned long flags; spin_lock_irqsave(&tick_device_lock, flags); - clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN); + clockevents_shutdown(td->evtdev); spin_unlock_irqrestore(&tick_device_lock, flags); } diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index f13f2b7..4692487 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -1,6 +1,10 @@ /* * tick internal variable and functions used by low/high res code */ + +#define TICK_DO_TIMER_NONE -1 +#define TICK_DO_TIMER_BOOT -2 + DECLARE_PER_CPU(struct tick_device, tick_cpu_device); extern spinlock_t tick_device_lock; extern ktime_t tick_next_period; @@ -10,6 +14,8 @@ extern int tick_do_timer_cpu __read_mostly; extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast); extern void tick_handle_periodic(struct clock_event_device *dev); +extern void clockevents_shutdown(struct clock_event_device *dev); + /* * NO_HZ / high resolution timer shared code */ @@ -17,6 +23,8 @@ extern void tick_handle_periodic(struct clock_event_device *dev); extern void tick_setup_oneshot(struct clock_event_device *newdev, void (*handler)(struct clock_event_device *), ktime_t nextevt); +extern int tick_dev_program_event(struct clock_event_device *dev, + ktime_t expires, int force); extern int tick_program_event(ktime_t expires, int force); extern void tick_oneshot_notify(void); extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *)); @@ -27,6 +35,7 @@ extern void tick_broadcast_oneshot_control(unsigned long reason); extern void tick_broadcast_switch_to_oneshot(void); extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup); extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc); +extern int tick_broadcast_oneshot_active(void); # else /* BROADCAST */ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { @@ -35,6 +44,7 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) static inline void tick_broadcast_oneshot_control(unsigned long reason) { } static inline void tick_broadcast_switch_to_oneshot(void) { } static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { } +static inline int tick_broadcast_oneshot_active(void) { return 0; } # endif /* !BROADCAST */ #else /* !ONESHOT */ @@ -64,6 +74,7 @@ static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc) { return 0; } +static inline int tick_broadcast_oneshot_active(void) { return 0; } #endif /* !TICK_ONESHOT */ /* diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index 450c049..2e8de67 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -23,24 +23,56 @@ #include "tick-internal.h" /** - * tick_program_event + * tick_program_event internal worker function */ -int tick_program_event(ktime_t expires, int force) +int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires, + int force) { - struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; ktime_t now = ktime_get(); + int i; - while (1) { + for (i = 0;;) { int ret = clockevents_program_event(dev, expires, now); if (!ret || !force) return ret; + + /* + * We tried 2 times to program the device with the given + * min_delta_ns. If that's not working then we double it + * and emit a warning. + */ + if (++i > 2) { + /* Increase the min. delta and try again */ + if (!dev->min_delta_ns) + dev->min_delta_ns = 5000; + else + dev->min_delta_ns += dev->min_delta_ns >> 1; + + printk(KERN_WARNING + "CE: %s increasing min_delta_ns to %lu nsec\n", + dev->name ? dev->name : "?", + dev->min_delta_ns << 1); + + i = 0; + } + now = ktime_get(); - expires = ktime_add(now, ktime_set(0, dev->min_delta_ns)); + expires = ktime_add_ns(now, dev->min_delta_ns); } } /** + * tick_program_event + */ +int tick_program_event(ktime_t expires, int force) +{ + struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; + + return tick_dev_program_event(dev, expires, force); +} + +/** * tick_resume_onshot - resume oneshot mode */ void tick_resume_oneshot(void) @@ -61,7 +93,7 @@ void tick_setup_oneshot(struct clock_event_device *newdev, { newdev->event_handler = handler; clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT); - clockevents_program_event(newdev, next_event, ktime_get()); + tick_dev_program_event(newdev, next_event, 1); } /** diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index b854a89..a4d2193 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -20,6 +20,7 @@ #include <linux/profile.h> #include <linux/sched.h> #include <linux/tick.h> +#include <linux/module.h> #include <asm/irq_regs.h> @@ -48,6 +49,13 @@ static void tick_do_update_jiffies64(ktime_t now) unsigned long ticks = 0; ktime_t delta; + /* + * Do a quick check without holding xtime_lock: + */ + delta = ktime_sub(now, last_jiffies_update); + if (delta.tv64 < tick_period.tv64) + return; + /* Reevalute with xtime_lock held */ write_seqlock(&xtime_lock); @@ -68,6 +76,9 @@ static void tick_do_update_jiffies64(ktime_t now) incr * ticks); } do_timer(++ticks); + + /* Keep the tick_next_period variable up to date */ + tick_next_period = ktime_add(last_jiffies_update, tick_period); } write_sequnlock(&xtime_lock); } @@ -133,8 +144,6 @@ void tick_nohz_update_jiffies(void) if (!ts->tick_stopped) return; - touch_softlockup_watchdog(); - cpu_clear(cpu, nohz_cpu_mask); now = ktime_get(); ts->idle_waketime = now; @@ -142,6 +151,8 @@ void tick_nohz_update_jiffies(void) local_irq_save(flags); tick_do_update_jiffies64(now); local_irq_restore(flags); + + touch_softlockup_watchdog(); } void tick_nohz_stop_idle(int cpu) @@ -155,6 +166,8 @@ void tick_nohz_stop_idle(int cpu) ts->idle_lastupdate = now; ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); ts->idle_active = 0; + + sched_clock_idle_wakeup_event(0); } } @@ -170,6 +183,7 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts) } ts->idle_entrytime = now; ts->idle_active = 1; + sched_clock_idle_sleep_event(); return now; } @@ -177,9 +191,17 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); - *last_update_time = ktime_to_us(ts->idle_lastupdate); + if (!tick_nohz_enabled) + return -1; + + if (ts->idle_active) + *last_update_time = ktime_to_us(ts->idle_lastupdate); + else + *last_update_time = ktime_to_us(ktime_get()); + return ktime_to_us(ts->idle_sleeptime); } +EXPORT_SYMBOL_GPL(get_cpu_idle_time_us); /** * tick_nohz_stop_sched_tick - stop the idle tick from the idle task @@ -188,7 +210,7 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) * Called either from the idle loop or from irq_exit() when an idle period was * just interrupted by an interrupt which did not cause a reschedule. */ -void tick_nohz_stop_sched_tick(void) +void tick_nohz_stop_sched_tick(int inidle) { unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags; struct tick_sched *ts; @@ -211,12 +233,17 @@ void tick_nohz_stop_sched_tick(void) */ if (unlikely(!cpu_online(cpu))) { if (cpu == tick_do_timer_cpu) - tick_do_timer_cpu = -1; + tick_do_timer_cpu = TICK_DO_TIMER_NONE; } if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) goto end; + if (!inidle && !ts->inidle) + goto end; + + ts->inidle = 1; + if (need_resched()) goto end; @@ -228,6 +255,7 @@ void tick_nohz_stop_sched_tick(void) local_softirq_pending()); ratelimit++; } + goto end; } ts->idle_calls++; @@ -287,7 +315,7 @@ void tick_nohz_stop_sched_tick(void) * invoked. */ if (cpu == tick_do_timer_cpu) - tick_do_timer_cpu = -1; + tick_do_timer_cpu = TICK_DO_TIMER_NONE; ts->idle_sleeps++; @@ -364,11 +392,14 @@ void tick_nohz_restart_sched_tick(void) local_irq_disable(); tick_nohz_stop_idle(cpu); - if (!ts->tick_stopped) { + if (!ts->inidle || !ts->tick_stopped) { + ts->inidle = 0; local_irq_enable(); return; } + ts->inidle = 0; + rcu_exit_nohz(); /* Update jiffies first */ @@ -449,7 +480,7 @@ static void tick_nohz_handler(struct clock_event_device *dev) * this duty, then the jiffies update is still serialized by * xtime_lock. */ - if (unlikely(tick_do_timer_cpu == -1)) + if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) tick_do_timer_cpu = cpu; /* Check, if the jiffies need an update */ @@ -551,7 +582,7 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer) * this duty, then the jiffies update is still serialized by * xtime_lock. */ - if (unlikely(tick_do_timer_cpu == -1)) + if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) tick_do_timer_cpu = cpu; #endif @@ -603,7 +634,7 @@ void tick_setup_sched_timer(void) */ hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); ts->sched_timer.function = tick_sched_timer; - ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; + ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU; /* Get the next period (per cpu) */ ts->sched_timer.expires = tick_init_jiffy_update(); @@ -627,17 +658,21 @@ void tick_setup_sched_timer(void) ts->nohz_mode = NOHZ_MODE_HIGHRES; #endif } +#endif /* HIGH_RES_TIMERS */ +#if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS void tick_cancel_sched_timer(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); +# ifdef CONFIG_HIGH_RES_TIMERS if (ts->sched_timer.base) hrtimer_cancel(&ts->sched_timer); +# endif ts->nohz_mode = NOHZ_MODE_INACTIVE; } -#endif /* HIGH_RES_TIMERS */ +#endif /** * Async notification about clocksource changes diff --git a/kernel/timer.c b/kernel/timer.c index ceacc66..03bc7f1 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -812,7 +812,7 @@ static inline void __run_timers(struct tvec_base *base) spin_unlock_irq(&base->lock); } -#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) +#ifdef CONFIG_NO_HZ /* * Find out when the next timer event is due to happen. This * is used on S/390 to stop all activity when a cpus is idle. @@ -947,14 +947,6 @@ unsigned long get_next_timer_interrupt(unsigned long now) return cmp_next_hrtimer_event(now, expires); } - -#ifdef CONFIG_NO_IDLE_HZ -unsigned long next_timer_interrupt(void) -{ - return get_next_timer_interrupt(jiffies); -} -#endif - #endif #ifndef CONFIG_VIRT_CPU_ACCOUNTING @@ -1502,7 +1494,7 @@ void __init init_timers(void) BUG_ON(err == NOTIFY_BAD); register_cpu_notifier(&timers_nb); - open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); + open_softirq(TIMER_SOFTIRQ, run_timer_softirq); } /** diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig new file mode 100644 index 0000000..263e9e6 --- /dev/null +++ b/kernel/trace/Kconfig @@ -0,0 +1,135 @@ +# +# Architectures that offer an FTRACE implementation should select HAVE_FTRACE: +# +config HAVE_FTRACE + bool + +config HAVE_DYNAMIC_FTRACE + bool + +config TRACER_MAX_TRACE + bool + +config TRACING + bool + select DEBUG_FS + select STACKTRACE + +config FTRACE + bool "Kernel Function Tracer" + depends on HAVE_FTRACE + select FRAME_POINTER + select TRACING + select CONTEXT_SWITCH_TRACER + help + Enable the kernel to trace every kernel function. This is done + by using a compiler feature to insert a small, 5-byte No-Operation + instruction to the beginning of every kernel function, which NOP + sequence is then dynamically patched into a tracer call when + tracing is enabled by the administrator. If it's runtime disabled + (the bootup default), then the overhead of the instructions is very + small and not measurable even in micro-benchmarks. + +config IRQSOFF_TRACER + bool "Interrupts-off Latency Tracer" + default n + depends on TRACE_IRQFLAGS_SUPPORT + depends on GENERIC_TIME + depends on HAVE_FTRACE + select TRACE_IRQFLAGS + select TRACING + select TRACER_MAX_TRACE + help + This option measures the time spent in irqs-off critical + sections, with microsecond accuracy. + + The default measurement method is a maximum search, which is + disabled by default and can be runtime (re-)started + via: + + echo 0 > /debugfs/tracing/tracing_max_latency + + (Note that kernel size and overhead increases with this option + enabled. This option and the preempt-off timing option can be + used together or separately.) + +config PREEMPT_TRACER + bool "Preemption-off Latency Tracer" + default n + depends on GENERIC_TIME + depends on PREEMPT + depends on HAVE_FTRACE + select TRACING + select TRACER_MAX_TRACE + help + This option measures the time spent in preemption off critical + sections, with microsecond accuracy. + + The default measurement method is a maximum search, which is + disabled by default and can be runtime (re-)started + via: + + echo 0 > /debugfs/tracing/tracing_max_latency + + (Note that kernel size and overhead increases with this option + enabled. This option and the irqs-off timing option can be + used together or separately.) + +config SYSPROF_TRACER + bool "Sysprof Tracer" + depends on X86 + select TRACING + help + This tracer provides the trace needed by the 'Sysprof' userspace + tool. + +config SCHED_TRACER + bool "Scheduling Latency Tracer" + depends on HAVE_FTRACE + select TRACING + select CONTEXT_SWITCH_TRACER + select TRACER_MAX_TRACE + help + This tracer tracks the latency of the highest priority task + to be scheduled in, starting from the point it has woken up. + +config CONTEXT_SWITCH_TRACER + bool "Trace process context switches" + depends on HAVE_FTRACE + select TRACING + select MARKERS + help + This tracer gets called from the context switch and records + all switching of tasks. + +config DYNAMIC_FTRACE + bool "enable/disable ftrace tracepoints dynamically" + depends on FTRACE + depends on HAVE_DYNAMIC_FTRACE + default y + help + This option will modify all the calls to ftrace dynamically + (will patch them out of the binary image and replaces them + with a No-Op instruction) as they are called. A table is + created to dynamically enable them again. + + This way a CONFIG_FTRACE kernel is slightly larger, but otherwise + has native performance as long as no tracing is active. + + The changes to the code are done by a kernel thread that + wakes up once a second and checks to see if any ftrace calls + were made. If so, it runs stop_machine (stops all CPUS) + and modifies the code to jump over the call to ftrace. + +config FTRACE_SELFTEST + bool + +config FTRACE_STARTUP_TEST + bool "Perform a startup test on ftrace" + depends on TRACING + select FTRACE_SELFTEST + help + This option performs a series of startup tests on ftrace. On bootup + a series of tests are made to verify that the tracer is + functioning properly. It will do tests on all the configured + tracers of ftrace. diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile new file mode 100644 index 0000000..71d17de --- /dev/null +++ b/kernel/trace/Makefile @@ -0,0 +1,24 @@ + +# Do not instrument the tracer itself: + +ifdef CONFIG_FTRACE +ORIG_CFLAGS := $(KBUILD_CFLAGS) +KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) + +# selftest needs instrumentation +CFLAGS_trace_selftest_dynamic.o = -pg +obj-y += trace_selftest_dynamic.o +endif + +obj-$(CONFIG_FTRACE) += libftrace.o + +obj-$(CONFIG_TRACING) += trace.o +obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o +obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o +obj-$(CONFIG_FTRACE) += trace_functions.o +obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o +obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o +obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o +obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o + +libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c new file mode 100644 index 0000000..f6e3af3 --- /dev/null +++ b/kernel/trace/ftrace.c @@ -0,0 +1,1727 @@ +/* + * Infrastructure for profiling code inserted by 'gcc -pg'. + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> + * + * Originally ported from the -rt patch by: + * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> + * + * Based on code in the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ + +#include <linux/stop_machine.h> +#include <linux/clocksource.h> +#include <linux/kallsyms.h> +#include <linux/seq_file.h> +#include <linux/debugfs.h> +#include <linux/hardirq.h> +#include <linux/kthread.h> +#include <linux/uaccess.h> +#include <linux/kprobes.h> +#include <linux/ftrace.h> +#include <linux/sysctl.h> +#include <linux/ctype.h> +#include <linux/hash.h> +#include <linux/list.h> + +#include <asm/ftrace.h> + +#include "trace.h" + +/* ftrace_enabled is a method to turn ftrace on or off */ +int ftrace_enabled __read_mostly; +static int last_ftrace_enabled; + +/* + * ftrace_disabled is set when an anomaly is discovered. + * ftrace_disabled is much stronger than ftrace_enabled. + */ +static int ftrace_disabled __read_mostly; + +static DEFINE_SPINLOCK(ftrace_lock); +static DEFINE_MUTEX(ftrace_sysctl_lock); + +static struct ftrace_ops ftrace_list_end __read_mostly = +{ + .func = ftrace_stub, +}; + +static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; +ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; + +static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) +{ + struct ftrace_ops *op = ftrace_list; + + /* in case someone actually ports this to alpha! */ + read_barrier_depends(); + + while (op != &ftrace_list_end) { + /* silly alpha */ + read_barrier_depends(); + op->func(ip, parent_ip); + op = op->next; + }; +} + +/** + * clear_ftrace_function - reset the ftrace function + * + * This NULLs the ftrace function and in essence stops + * tracing. There may be lag + */ +void clear_ftrace_function(void) +{ + ftrace_trace_function = ftrace_stub; +} + +static int __register_ftrace_function(struct ftrace_ops *ops) +{ + /* Should never be called by interrupts */ + spin_lock(&ftrace_lock); + + ops->next = ftrace_list; + /* + * We are entering ops into the ftrace_list but another + * CPU might be walking that list. We need to make sure + * the ops->next pointer is valid before another CPU sees + * the ops pointer included into the ftrace_list. + */ + smp_wmb(); + ftrace_list = ops; + + if (ftrace_enabled) { + /* + * For one func, simply call it directly. + * For more than one func, call the chain. + */ + if (ops->next == &ftrace_list_end) + ftrace_trace_function = ops->func; + else + ftrace_trace_function = ftrace_list_func; + } + + spin_unlock(&ftrace_lock); + + return 0; +} + +static int __unregister_ftrace_function(struct ftrace_ops *ops) +{ + struct ftrace_ops **p; + int ret = 0; + + spin_lock(&ftrace_lock); + + /* + * If we are removing the last function, then simply point + * to the ftrace_stub. + */ + if (ftrace_list == ops && ops->next == &ftrace_list_end) { + ftrace_trace_function = ftrace_stub; + ftrace_list = &ftrace_list_end; + goto out; + } + + for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) + if (*p == ops) + break; + + if (*p != ops) { + ret = -1; + goto out; + } + + *p = (*p)->next; + + if (ftrace_enabled) { + /* If we only have one func left, then call that directly */ + if (ftrace_list == &ftrace_list_end || + ftrace_list->next == &ftrace_list_end) + ftrace_trace_function = ftrace_list->func; + } + + out: + spin_unlock(&ftrace_lock); + + return ret; +} + +#ifdef CONFIG_DYNAMIC_FTRACE + +static struct task_struct *ftraced_task; + +enum { + FTRACE_ENABLE_CALLS = (1 << 0), + FTRACE_DISABLE_CALLS = (1 << 1), + FTRACE_UPDATE_TRACE_FUNC = (1 << 2), + FTRACE_ENABLE_MCOUNT = (1 << 3), + FTRACE_DISABLE_MCOUNT = (1 << 4), +}; + +static int ftrace_filtered; +static int tracing_on; +static int frozen_record_count; + +static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; + +static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); + +static DEFINE_SPINLOCK(ftrace_shutdown_lock); +static DEFINE_MUTEX(ftraced_lock); +static DEFINE_MUTEX(ftrace_regex_lock); + +struct ftrace_page { + struct ftrace_page *next; + unsigned long index; + struct dyn_ftrace records[]; +}; + +#define ENTRIES_PER_PAGE \ + ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) + +/* estimate from running different kernels */ +#define NR_TO_INIT 10000 + +static struct ftrace_page *ftrace_pages_start; +static struct ftrace_page *ftrace_pages; + +static int ftraced_trigger; +static int ftraced_suspend; +static int ftraced_stop; + +static int ftrace_record_suspend; + +static struct dyn_ftrace *ftrace_free_records; + + +#ifdef CONFIG_KPROBES +static inline void freeze_record(struct dyn_ftrace *rec) +{ + if (!(rec->flags & FTRACE_FL_FROZEN)) { + rec->flags |= FTRACE_FL_FROZEN; + frozen_record_count++; + } +} + +static inline void unfreeze_record(struct dyn_ftrace *rec) +{ + if (rec->flags & FTRACE_FL_FROZEN) { + rec->flags &= ~FTRACE_FL_FROZEN; + frozen_record_count--; + } +} + +static inline int record_frozen(struct dyn_ftrace *rec) +{ + return rec->flags & FTRACE_FL_FROZEN; +} +#else +# define freeze_record(rec) ({ 0; }) +# define unfreeze_record(rec) ({ 0; }) +# define record_frozen(rec) ({ 0; }) +#endif /* CONFIG_KPROBES */ + +int skip_trace(unsigned long ip) +{ + unsigned long fl; + struct dyn_ftrace *rec; + struct hlist_node *t; + struct hlist_head *head; + + if (frozen_record_count == 0) + return 0; + + head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; + hlist_for_each_entry_rcu(rec, t, head, node) { + if (rec->ip == ip) { + if (record_frozen(rec)) { + if (rec->flags & FTRACE_FL_FAILED) + return 1; + + if (!(rec->flags & FTRACE_FL_CONVERTED)) + return 1; + + if (!tracing_on || !ftrace_enabled) + return 1; + + if (ftrace_filtered) { + fl = rec->flags & (FTRACE_FL_FILTER | + FTRACE_FL_NOTRACE); + if (!fl || (fl & FTRACE_FL_NOTRACE)) + return 1; + } + } + break; + } + } + + return 0; +} + +static inline int +ftrace_ip_in_hash(unsigned long ip, unsigned long key) +{ + struct dyn_ftrace *p; + struct hlist_node *t; + int found = 0; + + hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { + if (p->ip == ip) { + found = 1; + break; + } + } + + return found; +} + +static inline void +ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) +{ + hlist_add_head_rcu(&node->node, &ftrace_hash[key]); +} + +/* called from kstop_machine */ +static inline void ftrace_del_hash(struct dyn_ftrace *node) +{ + hlist_del(&node->node); +} + +static void ftrace_free_rec(struct dyn_ftrace *rec) +{ + /* no locking, only called from kstop_machine */ + + rec->ip = (unsigned long)ftrace_free_records; + ftrace_free_records = rec; + rec->flags |= FTRACE_FL_FREE; +} + +static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) +{ + struct dyn_ftrace *rec; + + /* First check for freed records */ + if (ftrace_free_records) { + rec = ftrace_free_records; + + if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { + WARN_ON_ONCE(1); + ftrace_free_records = NULL; + ftrace_disabled = 1; + ftrace_enabled = 0; + return NULL; + } + + ftrace_free_records = (void *)rec->ip; + memset(rec, 0, sizeof(*rec)); + return rec; + } + + if (ftrace_pages->index == ENTRIES_PER_PAGE) { + if (!ftrace_pages->next) + return NULL; + ftrace_pages = ftrace_pages->next; + } + + return &ftrace_pages->records[ftrace_pages->index++]; +} + +static void +ftrace_record_ip(unsigned long ip) +{ + struct dyn_ftrace *node; + unsigned long flags; + unsigned long key; + int resched; + int atomic; + int cpu; + + if (!ftrace_enabled || ftrace_disabled) + return; + + resched = need_resched(); + preempt_disable_notrace(); + + /* + * We simply need to protect against recursion. + * Use the the raw version of smp_processor_id and not + * __get_cpu_var which can call debug hooks that can + * cause a recursive crash here. + */ + cpu = raw_smp_processor_id(); + per_cpu(ftrace_shutdown_disable_cpu, cpu)++; + if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) + goto out; + + if (unlikely(ftrace_record_suspend)) + goto out; + + key = hash_long(ip, FTRACE_HASHBITS); + + WARN_ON_ONCE(key >= FTRACE_HASHSIZE); + + if (ftrace_ip_in_hash(ip, key)) + goto out; + + atomic = irqs_disabled(); + + spin_lock_irqsave(&ftrace_shutdown_lock, flags); + + /* This ip may have hit the hash before the lock */ + if (ftrace_ip_in_hash(ip, key)) + goto out_unlock; + + node = ftrace_alloc_dyn_node(ip); + if (!node) + goto out_unlock; + + node->ip = ip; + + ftrace_add_hash(node, key); + + ftraced_trigger = 1; + + out_unlock: + spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); + out: + per_cpu(ftrace_shutdown_disable_cpu, cpu)--; + + /* prevent recursion with scheduler */ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + +#define FTRACE_ADDR ((long)(ftrace_caller)) + +static int +__ftrace_replace_code(struct dyn_ftrace *rec, + unsigned char *old, unsigned char *new, int enable) +{ + unsigned long ip, fl; + + ip = rec->ip; + + if (ftrace_filtered && enable) { + /* + * If filtering is on: + * + * If this record is set to be filtered and + * is enabled then do nothing. + * + * If this record is set to be filtered and + * it is not enabled, enable it. + * + * If this record is not set to be filtered + * and it is not enabled do nothing. + * + * If this record is set not to trace then + * do nothing. + * + * If this record is set not to trace and + * it is enabled then disable it. + * + * If this record is not set to be filtered and + * it is enabled, disable it. + */ + + fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | + FTRACE_FL_ENABLED); + + if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || + (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || + !fl || (fl == FTRACE_FL_NOTRACE)) + return 0; + + /* + * If it is enabled disable it, + * otherwise enable it! + */ + if (fl & FTRACE_FL_ENABLED) { + /* swap new and old */ + new = old; + old = ftrace_call_replace(ip, FTRACE_ADDR); + rec->flags &= ~FTRACE_FL_ENABLED; + } else { + new = ftrace_call_replace(ip, FTRACE_ADDR); + rec->flags |= FTRACE_FL_ENABLED; + } + } else { + + if (enable) { + /* + * If this record is set not to trace and is + * not enabled, do nothing. + */ + fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); + if (fl == FTRACE_FL_NOTRACE) + return 0; + + new = ftrace_call_replace(ip, FTRACE_ADDR); + } else + old = ftrace_call_replace(ip, FTRACE_ADDR); + + if (enable) { + if (rec->flags & FTRACE_FL_ENABLED) + return 0; + rec->flags |= FTRACE_FL_ENABLED; + } else { + if (!(rec->flags & FTRACE_FL_ENABLED)) + return 0; + rec->flags &= ~FTRACE_FL_ENABLED; + } + } + + return ftrace_modify_code(ip, old, new); +} + +static void ftrace_replace_code(int enable) +{ + int i, failed; + unsigned char *new = NULL, *old = NULL; + struct dyn_ftrace *rec; + struct ftrace_page *pg; + + if (enable) + old = ftrace_nop_replace(); + else + new = ftrace_nop_replace(); + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + + /* don't modify code that has already faulted */ + if (rec->flags & FTRACE_FL_FAILED) + continue; + + /* ignore updates to this record's mcount site */ + if (get_kprobe((void *)rec->ip)) { + freeze_record(rec); + continue; + } else { + unfreeze_record(rec); + } + + failed = __ftrace_replace_code(rec, old, new, enable); + if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { + rec->flags |= FTRACE_FL_FAILED; + if ((system_state == SYSTEM_BOOTING) || + !core_kernel_text(rec->ip)) { + ftrace_del_hash(rec); + ftrace_free_rec(rec); + } + } + } + } +} + +static void ftrace_shutdown_replenish(void) +{ + if (ftrace_pages->next) + return; + + /* allocate another page */ + ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); +} + +static int +ftrace_code_disable(struct dyn_ftrace *rec) +{ + unsigned long ip; + unsigned char *nop, *call; + int failed; + + ip = rec->ip; + + nop = ftrace_nop_replace(); + call = ftrace_call_replace(ip, MCOUNT_ADDR); + + failed = ftrace_modify_code(ip, call, nop); + if (failed) { + rec->flags |= FTRACE_FL_FAILED; + return 0; + } + return 1; +} + +static int __ftrace_update_code(void *ignore); + +static int __ftrace_modify_code(void *data) +{ + unsigned long addr; + int *command = data; + + if (*command & FTRACE_ENABLE_CALLS) { + /* + * Update any recorded ips now that we have the + * machine stopped + */ + __ftrace_update_code(NULL); + ftrace_replace_code(1); + tracing_on = 1; + } else if (*command & FTRACE_DISABLE_CALLS) { + ftrace_replace_code(0); + tracing_on = 0; + } + + if (*command & FTRACE_UPDATE_TRACE_FUNC) + ftrace_update_ftrace_func(ftrace_trace_function); + + if (*command & FTRACE_ENABLE_MCOUNT) { + addr = (unsigned long)ftrace_record_ip; + ftrace_mcount_set(&addr); + } else if (*command & FTRACE_DISABLE_MCOUNT) { + addr = (unsigned long)ftrace_stub; + ftrace_mcount_set(&addr); + } + + return 0; +} + +static void ftrace_run_update_code(int command) +{ + stop_machine(__ftrace_modify_code, &command, NULL); +} + +void ftrace_disable_daemon(void) +{ + /* Stop the daemon from calling kstop_machine */ + mutex_lock(&ftraced_lock); + ftraced_stop = 1; + mutex_unlock(&ftraced_lock); + + ftrace_force_update(); +} + +void ftrace_enable_daemon(void) +{ + mutex_lock(&ftraced_lock); + ftraced_stop = 0; + mutex_unlock(&ftraced_lock); + + ftrace_force_update(); +} + +static ftrace_func_t saved_ftrace_func; + +static void ftrace_startup(void) +{ + int command = 0; + + if (unlikely(ftrace_disabled)) + return; + + mutex_lock(&ftraced_lock); + ftraced_suspend++; + if (ftraced_suspend == 1) + command |= FTRACE_ENABLE_CALLS; + + if (saved_ftrace_func != ftrace_trace_function) { + saved_ftrace_func = ftrace_trace_function; + command |= FTRACE_UPDATE_TRACE_FUNC; + } + + if (!command || !ftrace_enabled) + goto out; + + ftrace_run_update_code(command); + out: + mutex_unlock(&ftraced_lock); +} + +static void ftrace_shutdown(void) +{ + int command = 0; + + if (unlikely(ftrace_disabled)) + return; + + mutex_lock(&ftraced_lock); + ftraced_suspend--; + if (!ftraced_suspend) + command |= FTRACE_DISABLE_CALLS; + + if (saved_ftrace_func != ftrace_trace_function) { + saved_ftrace_func = ftrace_trace_function; + command |= FTRACE_UPDATE_TRACE_FUNC; + } + + if (!command || !ftrace_enabled) + goto out; + + ftrace_run_update_code(command); + out: + mutex_unlock(&ftraced_lock); +} + +static void ftrace_startup_sysctl(void) +{ + int command = FTRACE_ENABLE_MCOUNT; + + if (unlikely(ftrace_disabled)) + return; + + mutex_lock(&ftraced_lock); + /* Force update next time */ + saved_ftrace_func = NULL; + /* ftraced_suspend is true if we want ftrace running */ + if (ftraced_suspend) + command |= FTRACE_ENABLE_CALLS; + + ftrace_run_update_code(command); + mutex_unlock(&ftraced_lock); +} + +static void ftrace_shutdown_sysctl(void) +{ + int command = FTRACE_DISABLE_MCOUNT; + + if (unlikely(ftrace_disabled)) + return; + + mutex_lock(&ftraced_lock); + /* ftraced_suspend is true if ftrace is running */ + if (ftraced_suspend) + command |= FTRACE_DISABLE_CALLS; + + ftrace_run_update_code(command); + mutex_unlock(&ftraced_lock); +} + +static cycle_t ftrace_update_time; +static unsigned long ftrace_update_cnt; +unsigned long ftrace_update_tot_cnt; + +static int __ftrace_update_code(void *ignore) +{ + int i, save_ftrace_enabled; + cycle_t start, stop; + struct dyn_ftrace *p; + struct hlist_node *t, *n; + struct hlist_head *head, temp_list; + + /* Don't be recording funcs now */ + ftrace_record_suspend++; + save_ftrace_enabled = ftrace_enabled; + ftrace_enabled = 0; + + start = ftrace_now(raw_smp_processor_id()); + ftrace_update_cnt = 0; + + /* No locks needed, the machine is stopped! */ + for (i = 0; i < FTRACE_HASHSIZE; i++) { + INIT_HLIST_HEAD(&temp_list); + head = &ftrace_hash[i]; + + /* all CPUS are stopped, we are safe to modify code */ + hlist_for_each_entry_safe(p, t, n, head, node) { + /* Skip over failed records which have not been + * freed. */ + if (p->flags & FTRACE_FL_FAILED) + continue; + + /* Unconverted records are always at the head of the + * hash bucket. Once we encounter a converted record, + * simply skip over to the next bucket. Saves ftraced + * some processor cycles (ftrace does its bid for + * global warming :-p ). */ + if (p->flags & (FTRACE_FL_CONVERTED)) + break; + + /* Ignore updates to this record's mcount site. + * Reintroduce this record at the head of this + * bucket to attempt to "convert" it again if + * the kprobe on it is unregistered before the + * next run. */ + if (get_kprobe((void *)p->ip)) { + ftrace_del_hash(p); + INIT_HLIST_NODE(&p->node); + hlist_add_head(&p->node, &temp_list); + freeze_record(p); + continue; + } else { + unfreeze_record(p); + } + + /* convert record (i.e, patch mcount-call with NOP) */ + if (ftrace_code_disable(p)) { + p->flags |= FTRACE_FL_CONVERTED; + ftrace_update_cnt++; + } else { + if ((system_state == SYSTEM_BOOTING) || + !core_kernel_text(p->ip)) { + ftrace_del_hash(p); + ftrace_free_rec(p); + } + } + } + + hlist_for_each_entry_safe(p, t, n, &temp_list, node) { + hlist_del(&p->node); + INIT_HLIST_NODE(&p->node); + hlist_add_head(&p->node, head); + } + } + + stop = ftrace_now(raw_smp_processor_id()); + ftrace_update_time = stop - start; + ftrace_update_tot_cnt += ftrace_update_cnt; + ftraced_trigger = 0; + + ftrace_enabled = save_ftrace_enabled; + ftrace_record_suspend--; + + return 0; +} + +static int ftrace_update_code(void) +{ + if (unlikely(ftrace_disabled) || + !ftrace_enabled || !ftraced_trigger) + return 0; + + stop_machine(__ftrace_update_code, NULL, NULL); + + return 1; +} + +static int ftraced(void *ignore) +{ + unsigned long usecs; + + while (!kthread_should_stop()) { + + set_current_state(TASK_INTERRUPTIBLE); + + /* check once a second */ + schedule_timeout(HZ); + + if (unlikely(ftrace_disabled)) + continue; + + mutex_lock(&ftrace_sysctl_lock); + mutex_lock(&ftraced_lock); + if (!ftraced_suspend && !ftraced_stop && + ftrace_update_code()) { + usecs = nsecs_to_usecs(ftrace_update_time); + if (ftrace_update_tot_cnt > 100000) { + ftrace_update_tot_cnt = 0; + pr_info("hm, dftrace overflow: %lu change%s" + " (%lu total) in %lu usec%s\n", + ftrace_update_cnt, + ftrace_update_cnt != 1 ? "s" : "", + ftrace_update_tot_cnt, + usecs, usecs != 1 ? "s" : ""); + ftrace_disabled = 1; + WARN_ON_ONCE(1); + } + } + mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_sysctl_lock); + + ftrace_shutdown_replenish(); + } + __set_current_state(TASK_RUNNING); + return 0; +} + +static int __init ftrace_dyn_table_alloc(void) +{ + struct ftrace_page *pg; + int cnt; + int i; + + /* allocate a few pages */ + ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); + if (!ftrace_pages_start) + return -1; + + /* + * Allocate a few more pages. + * + * TODO: have some parser search vmlinux before + * final linking to find all calls to ftrace. + * Then we can: + * a) know how many pages to allocate. + * and/or + * b) set up the table then. + * + * The dynamic code is still necessary for + * modules. + */ + + pg = ftrace_pages = ftrace_pages_start; + + cnt = NR_TO_INIT / ENTRIES_PER_PAGE; + + for (i = 0; i < cnt; i++) { + pg->next = (void *)get_zeroed_page(GFP_KERNEL); + + /* If we fail, we'll try later anyway */ + if (!pg->next) + break; + + pg = pg->next; + } + + return 0; +} + +enum { + FTRACE_ITER_FILTER = (1 << 0), + FTRACE_ITER_CONT = (1 << 1), + FTRACE_ITER_NOTRACE = (1 << 2), + FTRACE_ITER_FAILURES = (1 << 3), +}; + +#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ + +struct ftrace_iterator { + loff_t pos; + struct ftrace_page *pg; + unsigned idx; + unsigned flags; + unsigned char buffer[FTRACE_BUFF_MAX+1]; + unsigned buffer_idx; + unsigned filtered; +}; + +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct ftrace_iterator *iter = m->private; + struct dyn_ftrace *rec = NULL; + + (*pos)++; + + retry: + if (iter->idx >= iter->pg->index) { + if (iter->pg->next) { + iter->pg = iter->pg->next; + iter->idx = 0; + goto retry; + } + } else { + rec = &iter->pg->records[iter->idx++]; + if ((!(iter->flags & FTRACE_ITER_FAILURES) && + (rec->flags & FTRACE_FL_FAILED)) || + + ((iter->flags & FTRACE_ITER_FAILURES) && + (!(rec->flags & FTRACE_FL_FAILED) || + (rec->flags & FTRACE_FL_FREE))) || + + ((iter->flags & FTRACE_ITER_FILTER) && + !(rec->flags & FTRACE_FL_FILTER)) || + + ((iter->flags & FTRACE_ITER_NOTRACE) && + !(rec->flags & FTRACE_FL_NOTRACE))) { + rec = NULL; + goto retry; + } + } + + iter->pos = *pos; + + return rec; +} + +static void *t_start(struct seq_file *m, loff_t *pos) +{ + struct ftrace_iterator *iter = m->private; + void *p = NULL; + loff_t l = -1; + + if (*pos != iter->pos) { + for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) + ; + } else { + l = *pos; + p = t_next(m, p, &l); + } + + return p; +} + +static void t_stop(struct seq_file *m, void *p) +{ +} + +static int t_show(struct seq_file *m, void *v) +{ + struct dyn_ftrace *rec = v; + char str[KSYM_SYMBOL_LEN]; + + if (!rec) + return 0; + + kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); + + seq_printf(m, "%s\n", str); + + return 0; +} + +static struct seq_operations show_ftrace_seq_ops = { + .start = t_start, + .next = t_next, + .stop = t_stop, + .show = t_show, +}; + +static int +ftrace_avail_open(struct inode *inode, struct file *file) +{ + struct ftrace_iterator *iter; + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->pos = -1; + + ret = seq_open(file, &show_ftrace_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + + m->private = iter; + } else { + kfree(iter); + } + + return ret; +} + +int ftrace_avail_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = (struct seq_file *)file->private_data; + struct ftrace_iterator *iter = m->private; + + seq_release(inode, file); + kfree(iter); + + return 0; +} + +static int +ftrace_failures_open(struct inode *inode, struct file *file) +{ + int ret; + struct seq_file *m; + struct ftrace_iterator *iter; + + ret = ftrace_avail_open(inode, file); + if (!ret) { + m = (struct seq_file *)file->private_data; + iter = (struct ftrace_iterator *)m->private; + iter->flags = FTRACE_ITER_FAILURES; + } + + return ret; +} + + +static void ftrace_filter_reset(int enable) +{ + struct ftrace_page *pg; + struct dyn_ftrace *rec; + unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; + unsigned i; + + /* keep kstop machine from running */ + preempt_disable(); + if (enable) + ftrace_filtered = 0; + pg = ftrace_pages_start; + while (pg) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + if (rec->flags & FTRACE_FL_FAILED) + continue; + rec->flags &= ~type; + } + pg = pg->next; + } + preempt_enable(); +} + +static int +ftrace_regex_open(struct inode *inode, struct file *file, int enable) +{ + struct ftrace_iterator *iter; + int ret = 0; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return -ENOMEM; + + mutex_lock(&ftrace_regex_lock); + if ((file->f_mode & FMODE_WRITE) && + !(file->f_flags & O_APPEND)) + ftrace_filter_reset(enable); + + if (file->f_mode & FMODE_READ) { + iter->pg = ftrace_pages_start; + iter->pos = -1; + iter->flags = enable ? FTRACE_ITER_FILTER : + FTRACE_ITER_NOTRACE; + + ret = seq_open(file, &show_ftrace_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = iter; + } else + kfree(iter); + } else + file->private_data = iter; + mutex_unlock(&ftrace_regex_lock); + + return ret; +} + +static int +ftrace_filter_open(struct inode *inode, struct file *file) +{ + return ftrace_regex_open(inode, file, 1); +} + +static int +ftrace_notrace_open(struct inode *inode, struct file *file) +{ + return ftrace_regex_open(inode, file, 0); +} + +static ssize_t +ftrace_regex_read(struct file *file, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + if (file->f_mode & FMODE_READ) + return seq_read(file, ubuf, cnt, ppos); + else + return -EPERM; +} + +static loff_t +ftrace_regex_lseek(struct file *file, loff_t offset, int origin) +{ + loff_t ret; + + if (file->f_mode & FMODE_READ) + ret = seq_lseek(file, offset, origin); + else + file->f_pos = ret = 1; + + return ret; +} + +enum { + MATCH_FULL, + MATCH_FRONT_ONLY, + MATCH_MIDDLE_ONLY, + MATCH_END_ONLY, +}; + +static void +ftrace_match(unsigned char *buff, int len, int enable) +{ + char str[KSYM_SYMBOL_LEN]; + char *search = NULL; + struct ftrace_page *pg; + struct dyn_ftrace *rec; + int type = MATCH_FULL; + unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; + unsigned i, match = 0, search_len = 0; + + for (i = 0; i < len; i++) { + if (buff[i] == '*') { + if (!i) { + search = buff + i + 1; + type = MATCH_END_ONLY; + search_len = len - (i + 1); + } else { + if (type == MATCH_END_ONLY) { + type = MATCH_MIDDLE_ONLY; + } else { + match = i; + type = MATCH_FRONT_ONLY; + } + buff[i] = 0; + break; + } + } + } + + /* keep kstop machine from running */ + preempt_disable(); + if (enable) + ftrace_filtered = 1; + pg = ftrace_pages_start; + while (pg) { + for (i = 0; i < pg->index; i++) { + int matched = 0; + char *ptr; + + rec = &pg->records[i]; + if (rec->flags & FTRACE_FL_FAILED) + continue; + kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); + switch (type) { + case MATCH_FULL: + if (strcmp(str, buff) == 0) + matched = 1; + break; + case MATCH_FRONT_ONLY: + if (memcmp(str, buff, match) == 0) + matched = 1; + break; + case MATCH_MIDDLE_ONLY: + if (strstr(str, search)) + matched = 1; + break; + case MATCH_END_ONLY: + ptr = strstr(str, search); + if (ptr && (ptr[search_len] == 0)) + matched = 1; + break; + } + if (matched) + rec->flags |= flag; + } + pg = pg->next; + } + preempt_enable(); +} + +static ssize_t +ftrace_regex_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos, int enable) +{ + struct ftrace_iterator *iter; + char ch; + size_t read = 0; + ssize_t ret; + + if (!cnt || cnt < 0) + return 0; + + mutex_lock(&ftrace_regex_lock); + + if (file->f_mode & FMODE_READ) { + struct seq_file *m = file->private_data; + iter = m->private; + } else + iter = file->private_data; + + if (!*ppos) { + iter->flags &= ~FTRACE_ITER_CONT; + iter->buffer_idx = 0; + } + + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + + if (!(iter->flags & ~FTRACE_ITER_CONT)) { + /* skip white space */ + while (cnt && isspace(ch)) { + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + + if (isspace(ch)) { + file->f_pos += read; + ret = read; + goto out; + } + + iter->buffer_idx = 0; + } + + while (cnt && !isspace(ch)) { + if (iter->buffer_idx < FTRACE_BUFF_MAX) + iter->buffer[iter->buffer_idx++] = ch; + else { + ret = -EINVAL; + goto out; + } + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + + if (isspace(ch)) { + iter->filtered++; + iter->buffer[iter->buffer_idx] = 0; + ftrace_match(iter->buffer, iter->buffer_idx, enable); + iter->buffer_idx = 0; + } else + iter->flags |= FTRACE_ITER_CONT; + + + file->f_pos += read; + + ret = read; + out: + mutex_unlock(&ftrace_regex_lock); + + return ret; +} + +static ssize_t +ftrace_filter_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return ftrace_regex_write(file, ubuf, cnt, ppos, 1); +} + +static ssize_t +ftrace_notrace_write(struct file *file, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return ftrace_regex_write(file, ubuf, cnt, ppos, 0); +} + +static void +ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) +{ + if (unlikely(ftrace_disabled)) + return; + + mutex_lock(&ftrace_regex_lock); + if (reset) + ftrace_filter_reset(enable); + if (buf) + ftrace_match(buf, len, enable); + mutex_unlock(&ftrace_regex_lock); +} + +/** + * ftrace_set_filter - set a function to filter on in ftrace + * @buf - the string that holds the function filter text. + * @len - the length of the string. + * @reset - non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled. + * If @buf is NULL and reset is set, all functions will be enabled for tracing. + */ +void ftrace_set_filter(unsigned char *buf, int len, int reset) +{ + ftrace_set_regex(buf, len, reset, 1); +} + +/** + * ftrace_set_notrace - set a function to not trace in ftrace + * @buf - the string that holds the function notrace text. + * @len - the length of the string. + * @reset - non zero to reset all filters before applying this filter. + * + * Notrace Filters denote which functions should not be enabled when tracing + * is enabled. If @buf is NULL and reset is set, all functions will be enabled + * for tracing. + */ +void ftrace_set_notrace(unsigned char *buf, int len, int reset) +{ + ftrace_set_regex(buf, len, reset, 0); +} + +static int +ftrace_regex_release(struct inode *inode, struct file *file, int enable) +{ + struct seq_file *m = (struct seq_file *)file->private_data; + struct ftrace_iterator *iter; + + mutex_lock(&ftrace_regex_lock); + if (file->f_mode & FMODE_READ) { + iter = m->private; + + seq_release(inode, file); + } else + iter = file->private_data; + + if (iter->buffer_idx) { + iter->filtered++; + iter->buffer[iter->buffer_idx] = 0; + ftrace_match(iter->buffer, iter->buffer_idx, enable); + } + + mutex_lock(&ftrace_sysctl_lock); + mutex_lock(&ftraced_lock); + if (iter->filtered && ftraced_suspend && ftrace_enabled) + ftrace_run_update_code(FTRACE_ENABLE_CALLS); + mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_sysctl_lock); + + kfree(iter); + mutex_unlock(&ftrace_regex_lock); + return 0; +} + +static int +ftrace_filter_release(struct inode *inode, struct file *file) +{ + return ftrace_regex_release(inode, file, 1); +} + +static int +ftrace_notrace_release(struct inode *inode, struct file *file) +{ + return ftrace_regex_release(inode, file, 0); +} + +static ssize_t +ftraced_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + /* don't worry about races */ + char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; + int r = strlen(buf); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +ftraced_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[64]; + long val; + int ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + if (strncmp(buf, "enable", 6) == 0) + val = 1; + else if (strncmp(buf, "disable", 7) == 0) + val = 0; + else { + buf[cnt] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + val = !!val; + } + + if (val) + ftrace_enable_daemon(); + else + ftrace_disable_daemon(); + + filp->f_pos += cnt; + + return cnt; +} + +static struct file_operations ftrace_avail_fops = { + .open = ftrace_avail_open, + .read = seq_read, + .llseek = seq_lseek, + .release = ftrace_avail_release, +}; + +static struct file_operations ftrace_failures_fops = { + .open = ftrace_failures_open, + .read = seq_read, + .llseek = seq_lseek, + .release = ftrace_avail_release, +}; + +static struct file_operations ftrace_filter_fops = { + .open = ftrace_filter_open, + .read = ftrace_regex_read, + .write = ftrace_filter_write, + .llseek = ftrace_regex_lseek, + .release = ftrace_filter_release, +}; + +static struct file_operations ftrace_notrace_fops = { + .open = ftrace_notrace_open, + .read = ftrace_regex_read, + .write = ftrace_notrace_write, + .llseek = ftrace_regex_lseek, + .release = ftrace_notrace_release, +}; + +static struct file_operations ftraced_fops = { + .open = tracing_open_generic, + .read = ftraced_read, + .write = ftraced_write, +}; + +/** + * ftrace_force_update - force an update to all recording ftrace functions + */ +int ftrace_force_update(void) +{ + int ret = 0; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + mutex_lock(&ftrace_sysctl_lock); + mutex_lock(&ftraced_lock); + + /* + * If ftraced_trigger is not set, then there is nothing + * to update. + */ + if (ftraced_trigger && !ftrace_update_code()) + ret = -EBUSY; + + mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_sysctl_lock); + + return ret; +} + +static void ftrace_force_shutdown(void) +{ + struct task_struct *task; + int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; + + mutex_lock(&ftraced_lock); + task = ftraced_task; + ftraced_task = NULL; + ftraced_suspend = -1; + ftrace_run_update_code(command); + mutex_unlock(&ftraced_lock); + + if (task) + kthread_stop(task); +} + +static __init int ftrace_init_debugfs(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + + d_tracer = tracing_init_dentry(); + + entry = debugfs_create_file("available_filter_functions", 0444, + d_tracer, NULL, &ftrace_avail_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'available_filter_functions' entry\n"); + + entry = debugfs_create_file("failures", 0444, + d_tracer, NULL, &ftrace_failures_fops); + if (!entry) + pr_warning("Could not create debugfs 'failures' entry\n"); + + entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, + NULL, &ftrace_filter_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'set_ftrace_filter' entry\n"); + + entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, + NULL, &ftrace_notrace_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'set_ftrace_notrace' entry\n"); + + entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, + NULL, &ftraced_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'ftraced_enabled' entry\n"); + return 0; +} + +fs_initcall(ftrace_init_debugfs); + +static int __init ftrace_dynamic_init(void) +{ + struct task_struct *p; + unsigned long addr; + int ret; + + addr = (unsigned long)ftrace_record_ip; + + stop_machine(ftrace_dyn_arch_init, &addr, NULL); + + /* ftrace_dyn_arch_init places the return code in addr */ + if (addr) { + ret = (int)addr; + goto failed; + } + + ret = ftrace_dyn_table_alloc(); + if (ret) + goto failed; + + p = kthread_run(ftraced, NULL, "ftraced"); + if (IS_ERR(p)) { + ret = -1; + goto failed; + } + + last_ftrace_enabled = ftrace_enabled = 1; + ftraced_task = p; + + return 0; + + failed: + ftrace_disabled = 1; + return ret; +} + +core_initcall(ftrace_dynamic_init); +#else +# define ftrace_startup() do { } while (0) +# define ftrace_shutdown() do { } while (0) +# define ftrace_startup_sysctl() do { } while (0) +# define ftrace_shutdown_sysctl() do { } while (0) +# define ftrace_force_shutdown() do { } while (0) +#endif /* CONFIG_DYNAMIC_FTRACE */ + +/** + * ftrace_kill_atomic - kill ftrace from critical sections + * + * This function should be used by panic code. It stops ftrace + * but in a not so nice way. If you need to simply kill ftrace + * from a non-atomic section, use ftrace_kill. + */ +void ftrace_kill_atomic(void) +{ + ftrace_disabled = 1; + ftrace_enabled = 0; +#ifdef CONFIG_DYNAMIC_FTRACE + ftraced_suspend = -1; +#endif + clear_ftrace_function(); +} + +/** + * ftrace_kill - totally shutdown ftrace + * + * This is a safety measure. If something was detected that seems + * wrong, calling this function will keep ftrace from doing + * any more modifications, and updates. + * used when something went wrong. + */ +void ftrace_kill(void) +{ + mutex_lock(&ftrace_sysctl_lock); + ftrace_disabled = 1; + ftrace_enabled = 0; + + clear_ftrace_function(); + mutex_unlock(&ftrace_sysctl_lock); + + /* Try to totally disable ftrace */ + ftrace_force_shutdown(); +} + +/** + * register_ftrace_function - register a function for profiling + * @ops - ops structure that holds the function for profiling. + * + * Register a function to be called by all functions in the + * kernel. + * + * Note: @ops->func and all the functions it calls must be labeled + * with "notrace", otherwise it will go into a + * recursive loop. + */ +int register_ftrace_function(struct ftrace_ops *ops) +{ + int ret; + + if (unlikely(ftrace_disabled)) + return -1; + + mutex_lock(&ftrace_sysctl_lock); + ret = __register_ftrace_function(ops); + ftrace_startup(); + mutex_unlock(&ftrace_sysctl_lock); + + return ret; +} + +/** + * unregister_ftrace_function - unresgister a function for profiling. + * @ops - ops structure that holds the function to unregister + * + * Unregister a function that was added to be called by ftrace profiling. + */ +int unregister_ftrace_function(struct ftrace_ops *ops) +{ + int ret; + + mutex_lock(&ftrace_sysctl_lock); + ret = __unregister_ftrace_function(ops); + ftrace_shutdown(); + mutex_unlock(&ftrace_sysctl_lock); + + return ret; +} + +int +ftrace_enable_sysctl(struct ctl_table *table, int write, + struct file *file, void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + mutex_lock(&ftrace_sysctl_lock); + + ret = proc_dointvec(table, write, file, buffer, lenp, ppos); + + if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) + goto out; + + last_ftrace_enabled = ftrace_enabled; + + if (ftrace_enabled) { + + ftrace_startup_sysctl(); + + /* we are starting ftrace again */ + if (ftrace_list != &ftrace_list_end) { + if (ftrace_list->next == &ftrace_list_end) + ftrace_trace_function = ftrace_list->func; + else + ftrace_trace_function = ftrace_list_func; + } + + } else { + /* stopping ftrace calls (just send to ftrace_stub) */ + ftrace_trace_function = ftrace_stub; + + ftrace_shutdown_sysctl(); + } + + out: + mutex_unlock(&ftrace_sysctl_lock); + return ret; +} diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c new file mode 100644 index 0000000..8f3fb3d --- /dev/null +++ b/kernel/trace/trace.c @@ -0,0 +1,3157 @@ +/* + * ring buffer based function tracer + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + * + * Originally taken from the RT patch by: + * Arnaldo Carvalho de Melo <acme@redhat.com> + * + * Based on code from the latency_tracer, that is: + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ +#include <linux/utsrelease.h> +#include <linux/kallsyms.h> +#include <linux/seq_file.h> +#include <linux/debugfs.h> +#include <linux/pagemap.h> +#include <linux/hardirq.h> +#include <linux/linkage.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/ctype.h> +#include <linux/init.h> +#include <linux/poll.h> +#include <linux/gfp.h> +#include <linux/fs.h> +#include <linux/kprobes.h> +#include <linux/writeback.h> + +#include <linux/stacktrace.h> + +#include "trace.h" + +unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; +unsigned long __read_mostly tracing_thresh; + +static unsigned long __read_mostly tracing_nr_buffers; +static cpumask_t __read_mostly tracing_buffer_mask; + +#define for_each_tracing_cpu(cpu) \ + for_each_cpu_mask(cpu, tracing_buffer_mask) + +static int trace_alloc_page(void); +static int trace_free_page(void); + +static int tracing_disabled = 1; + +static unsigned long tracing_pages_allocated; + +long +ns2usecs(cycle_t nsec) +{ + nsec += 500; + do_div(nsec, 1000); + return nsec; +} + +cycle_t ftrace_now(int cpu) +{ + return cpu_clock(cpu); +} + +/* + * The global_trace is the descriptor that holds the tracing + * buffers for the live tracing. For each CPU, it contains + * a link list of pages that will store trace entries. The + * page descriptor of the pages in the memory is used to hold + * the link list by linking the lru item in the page descriptor + * to each of the pages in the buffer per CPU. + * + * For each active CPU there is a data field that holds the + * pages for the buffer for that CPU. Each CPU has the same number + * of pages allocated for its buffer. + */ +static struct trace_array global_trace; + +static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); + +/* + * The max_tr is used to snapshot the global_trace when a maximum + * latency is reached. Some tracers will use this to store a maximum + * trace while it continues examining live traces. + * + * The buffers for the max_tr are set up the same as the global_trace. + * When a snapshot is taken, the link list of the max_tr is swapped + * with the link list of the global_trace and the buffers are reset for + * the global_trace so the tracing can continue. + */ +static struct trace_array max_tr; + +static DEFINE_PER_CPU(struct trace_array_cpu, max_data); + +/* tracer_enabled is used to toggle activation of a tracer */ +static int tracer_enabled = 1; + +/* function tracing enabled */ +int ftrace_function_enabled; + +/* + * trace_nr_entries is the number of entries that is allocated + * for a buffer. Note, the number of entries is always rounded + * to ENTRIES_PER_PAGE. + */ +static unsigned long trace_nr_entries = 65536UL; + +/* trace_types holds a link list of available tracers. */ +static struct tracer *trace_types __read_mostly; + +/* current_trace points to the tracer that is currently active */ +static struct tracer *current_trace __read_mostly; + +/* + * max_tracer_type_len is used to simplify the allocating of + * buffers to read userspace tracer names. We keep track of + * the longest tracer name registered. + */ +static int max_tracer_type_len; + +/* + * trace_types_lock is used to protect the trace_types list. + * This lock is also used to keep user access serialized. + * Accesses from userspace will grab this lock while userspace + * activities happen inside the kernel. + */ +static DEFINE_MUTEX(trace_types_lock); + +/* trace_wait is a waitqueue for tasks blocked on trace_poll */ +static DECLARE_WAIT_QUEUE_HEAD(trace_wait); + +/* trace_flags holds iter_ctrl options */ +unsigned long trace_flags = TRACE_ITER_PRINT_PARENT; + +static notrace void no_trace_init(struct trace_array *tr) +{ + int cpu; + + ftrace_function_enabled = 0; + if(tr->ctrl) + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); + tracer_enabled = 0; +} + +/* dummy trace to disable tracing */ +static struct tracer no_tracer __read_mostly = { + .name = "none", + .init = no_trace_init +}; + + +/** + * trace_wake_up - wake up tasks waiting for trace input + * + * Simply wakes up any task that is blocked on the trace_wait + * queue. These is used with trace_poll for tasks polling the trace. + */ +void trace_wake_up(void) +{ + /* + * The runqueue_is_locked() can fail, but this is the best we + * have for now: + */ + if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) + wake_up(&trace_wait); +} + +#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) + +static int __init set_nr_entries(char *str) +{ + unsigned long nr_entries; + int ret; + + if (!str) + return 0; + ret = strict_strtoul(str, 0, &nr_entries); + /* nr_entries can not be zero */ + if (ret < 0 || nr_entries == 0) + return 0; + trace_nr_entries = nr_entries; + return 1; +} +__setup("trace_entries=", set_nr_entries); + +unsigned long nsecs_to_usecs(unsigned long nsecs) +{ + return nsecs / 1000; +} + +/* + * trace_flag_type is an enumeration that holds different + * states when a trace occurs. These are: + * IRQS_OFF - interrupts were disabled + * NEED_RESCED - reschedule is requested + * HARDIRQ - inside an interrupt handler + * SOFTIRQ - inside a softirq handler + */ +enum trace_flag_type { + TRACE_FLAG_IRQS_OFF = 0x01, + TRACE_FLAG_NEED_RESCHED = 0x02, + TRACE_FLAG_HARDIRQ = 0x04, + TRACE_FLAG_SOFTIRQ = 0x08, +}; + +/* + * TRACE_ITER_SYM_MASK masks the options in trace_flags that + * control the output of kernel symbols. + */ +#define TRACE_ITER_SYM_MASK \ + (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) + +/* These must match the bit postions in trace_iterator_flags */ +static const char *trace_options[] = { + "print-parent", + "sym-offset", + "sym-addr", + "verbose", + "raw", + "hex", + "bin", + "block", + "stacktrace", + "sched-tree", + NULL +}; + +/* + * ftrace_max_lock is used to protect the swapping of buffers + * when taking a max snapshot. The buffers themselves are + * protected by per_cpu spinlocks. But the action of the swap + * needs its own lock. + * + * This is defined as a raw_spinlock_t in order to help + * with performance when lockdep debugging is enabled. + */ +static raw_spinlock_t ftrace_max_lock = + (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + +/* + * Copy the new maximum trace into the separate maximum-trace + * structure. (this way the maximum trace is permanently saved, + * for later retrieval via /debugfs/tracing/latency_trace) + */ +static void +__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) +{ + struct trace_array_cpu *data = tr->data[cpu]; + + max_tr.cpu = cpu; + max_tr.time_start = data->preempt_timestamp; + + data = max_tr.data[cpu]; + data->saved_latency = tracing_max_latency; + + memcpy(data->comm, tsk->comm, TASK_COMM_LEN); + data->pid = tsk->pid; + data->uid = tsk->uid; + data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; + data->policy = tsk->policy; + data->rt_priority = tsk->rt_priority; + + /* record this tasks comm */ + tracing_record_cmdline(current); +} + +#define CHECK_COND(cond) \ + if (unlikely(cond)) { \ + tracing_disabled = 1; \ + WARN_ON(1); \ + return -1; \ + } + +/** + * check_pages - integrity check of trace buffers + * + * As a safty measure we check to make sure the data pages have not + * been corrupted. + */ +int check_pages(struct trace_array_cpu *data) +{ + struct page *page, *tmp; + + CHECK_COND(data->trace_pages.next->prev != &data->trace_pages); + CHECK_COND(data->trace_pages.prev->next != &data->trace_pages); + + list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { + CHECK_COND(page->lru.next->prev != &page->lru); + CHECK_COND(page->lru.prev->next != &page->lru); + } + + return 0; +} + +/** + * head_page - page address of the first page in per_cpu buffer. + * + * head_page returns the page address of the first page in + * a per_cpu buffer. This also preforms various consistency + * checks to make sure the buffer has not been corrupted. + */ +void *head_page(struct trace_array_cpu *data) +{ + struct page *page; + + if (list_empty(&data->trace_pages)) + return NULL; + + page = list_entry(data->trace_pages.next, struct page, lru); + BUG_ON(&page->lru == &data->trace_pages); + + return page_address(page); +} + +/** + * trace_seq_printf - sequence printing of trace information + * @s: trace sequence descriptor + * @fmt: printf format string + * + * The tracer may use either sequence operations or its own + * copy to user routines. To simplify formating of a trace + * trace_seq_printf is used to store strings into a special + * buffer (@s). Then the output may be either used by + * the sequencer or pulled into another buffer. + */ +int +trace_seq_printf(struct trace_seq *s, const char *fmt, ...) +{ + int len = (PAGE_SIZE - 1) - s->len; + va_list ap; + int ret; + + if (!len) + return 0; + + va_start(ap, fmt); + ret = vsnprintf(s->buffer + s->len, len, fmt, ap); + va_end(ap); + + /* If we can't write it all, don't bother writing anything */ + if (ret >= len) + return 0; + + s->len += ret; + + return len; +} + +/** + * trace_seq_puts - trace sequence printing of simple string + * @s: trace sequence descriptor + * @str: simple string to record + * + * The tracer may use either the sequence operations or its own + * copy to user routines. This function records a simple string + * into a special buffer (@s) for later retrieval by a sequencer + * or other mechanism. + */ +static int +trace_seq_puts(struct trace_seq *s, const char *str) +{ + int len = strlen(str); + + if (len > ((PAGE_SIZE - 1) - s->len)) + return 0; + + memcpy(s->buffer + s->len, str, len); + s->len += len; + + return len; +} + +static int +trace_seq_putc(struct trace_seq *s, unsigned char c) +{ + if (s->len >= (PAGE_SIZE - 1)) + return 0; + + s->buffer[s->len++] = c; + + return 1; +} + +static int +trace_seq_putmem(struct trace_seq *s, void *mem, size_t len) +{ + if (len > ((PAGE_SIZE - 1) - s->len)) + return 0; + + memcpy(s->buffer + s->len, mem, len); + s->len += len; + + return len; +} + +#define HEX_CHARS 17 +static const char hex2asc[] = "0123456789abcdef"; + +static int +trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) +{ + unsigned char hex[HEX_CHARS]; + unsigned char *data = mem; + unsigned char byte; + int i, j; + + BUG_ON(len >= HEX_CHARS); + +#ifdef __BIG_ENDIAN + for (i = 0, j = 0; i < len; i++) { +#else + for (i = len-1, j = 0; i >= 0; i--) { +#endif + byte = data[i]; + + hex[j++] = hex2asc[byte & 0x0f]; + hex[j++] = hex2asc[byte >> 4]; + } + hex[j++] = ' '; + + return trace_seq_putmem(s, hex, j); +} + +static void +trace_seq_reset(struct trace_seq *s) +{ + s->len = 0; + s->readpos = 0; +} + +ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) +{ + int len; + int ret; + + if (s->len <= s->readpos) + return -EBUSY; + + len = s->len - s->readpos; + if (cnt > len) + cnt = len; + ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); + if (ret) + return -EFAULT; + + s->readpos += len; + return cnt; +} + +static void +trace_print_seq(struct seq_file *m, struct trace_seq *s) +{ + int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; + + s->buffer[len] = 0; + seq_puts(m, s->buffer); + + trace_seq_reset(s); +} + +/* + * flip the trace buffers between two trace descriptors. + * This usually is the buffers between the global_trace and + * the max_tr to record a snapshot of a current trace. + * + * The ftrace_max_lock must be held. + */ +static void +flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) +{ + struct list_head flip_pages; + + INIT_LIST_HEAD(&flip_pages); + + memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, + sizeof(struct trace_array_cpu) - + offsetof(struct trace_array_cpu, trace_head_idx)); + + check_pages(tr1); + check_pages(tr2); + list_splice_init(&tr1->trace_pages, &flip_pages); + list_splice_init(&tr2->trace_pages, &tr1->trace_pages); + list_splice_init(&flip_pages, &tr2->trace_pages); + BUG_ON(!list_empty(&flip_pages)); + check_pages(tr1); + check_pages(tr2); +} + +/** + * update_max_tr - snapshot all trace buffers from global_trace to max_tr + * @tr: tracer + * @tsk: the task with the latency + * @cpu: The cpu that initiated the trace. + * + * Flip the buffers between the @tr and the max_tr and record information + * about which task was the cause of this latency. + */ +void +update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) +{ + struct trace_array_cpu *data; + int i; + + WARN_ON_ONCE(!irqs_disabled()); + __raw_spin_lock(&ftrace_max_lock); + /* clear out all the previous traces */ + for_each_tracing_cpu(i) { + data = tr->data[i]; + flip_trace(max_tr.data[i], data); + tracing_reset(data); + } + + __update_max_tr(tr, tsk, cpu); + __raw_spin_unlock(&ftrace_max_lock); +} + +/** + * update_max_tr_single - only copy one trace over, and reset the rest + * @tr - tracer + * @tsk - task with the latency + * @cpu - the cpu of the buffer to copy. + * + * Flip the trace of a single CPU buffer between the @tr and the max_tr. + */ +void +update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) +{ + struct trace_array_cpu *data = tr->data[cpu]; + int i; + + WARN_ON_ONCE(!irqs_disabled()); + __raw_spin_lock(&ftrace_max_lock); + for_each_tracing_cpu(i) + tracing_reset(max_tr.data[i]); + + flip_trace(max_tr.data[cpu], data); + tracing_reset(data); + + __update_max_tr(tr, tsk, cpu); + __raw_spin_unlock(&ftrace_max_lock); +} + +/** + * register_tracer - register a tracer with the ftrace system. + * @type - the plugin for the tracer + * + * Register a new plugin tracer. + */ +int register_tracer(struct tracer *type) +{ + struct tracer *t; + int len; + int ret = 0; + + if (!type->name) { + pr_info("Tracer must have a name\n"); + return -1; + } + + mutex_lock(&trace_types_lock); + for (t = trace_types; t; t = t->next) { + if (strcmp(type->name, t->name) == 0) { + /* already found */ + pr_info("Trace %s already registered\n", + type->name); + ret = -1; + goto out; + } + } + +#ifdef CONFIG_FTRACE_STARTUP_TEST + if (type->selftest) { + struct tracer *saved_tracer = current_trace; + struct trace_array_cpu *data; + struct trace_array *tr = &global_trace; + int saved_ctrl = tr->ctrl; + int i; + /* + * Run a selftest on this tracer. + * Here we reset the trace buffer, and set the current + * tracer to be this tracer. The tracer can then run some + * internal tracing to verify that everything is in order. + * If we fail, we do not register this tracer. + */ + for_each_tracing_cpu(i) { + data = tr->data[i]; + if (!head_page(data)) + continue; + tracing_reset(data); + } + current_trace = type; + tr->ctrl = 0; + /* the test is responsible for initializing and enabling */ + pr_info("Testing tracer %s: ", type->name); + ret = type->selftest(type, tr); + /* the test is responsible for resetting too */ + current_trace = saved_tracer; + tr->ctrl = saved_ctrl; + if (ret) { + printk(KERN_CONT "FAILED!\n"); + goto out; + } + /* Only reset on passing, to avoid touching corrupted buffers */ + for_each_tracing_cpu(i) { + data = tr->data[i]; + if (!head_page(data)) + continue; + tracing_reset(data); + } + printk(KERN_CONT "PASSED\n"); + } +#endif + + type->next = trace_types; + trace_types = type; + len = strlen(type->name); + if (len > max_tracer_type_len) + max_tracer_type_len = len; + + out: + mutex_unlock(&trace_types_lock); + + return ret; +} + +void unregister_tracer(struct tracer *type) +{ + struct tracer **t; + int len; + + mutex_lock(&trace_types_lock); + for (t = &trace_types; *t; t = &(*t)->next) { + if (*t == type) + goto found; + } + pr_info("Trace %s not registered\n", type->name); + goto out; + + found: + *t = (*t)->next; + if (strlen(type->name) != max_tracer_type_len) + goto out; + + max_tracer_type_len = 0; + for (t = &trace_types; *t; t = &(*t)->next) { + len = strlen((*t)->name); + if (len > max_tracer_type_len) + max_tracer_type_len = len; + } + out: + mutex_unlock(&trace_types_lock); +} + +void tracing_reset(struct trace_array_cpu *data) +{ + data->trace_idx = 0; + data->overrun = 0; + data->trace_head = data->trace_tail = head_page(data); + data->trace_head_idx = 0; + data->trace_tail_idx = 0; +} + +#define SAVED_CMDLINES 128 +static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; +static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; +static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; +static int cmdline_idx; +static DEFINE_SPINLOCK(trace_cmdline_lock); + +/* temporary disable recording */ +atomic_t trace_record_cmdline_disabled __read_mostly; + +static void trace_init_cmdlines(void) +{ + memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); + memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); + cmdline_idx = 0; +} + +void trace_stop_cmdline_recording(void); + +static void trace_save_cmdline(struct task_struct *tsk) +{ + unsigned map; + unsigned idx; + + if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) + return; + + /* + * It's not the end of the world if we don't get + * the lock, but we also don't want to spin + * nor do we want to disable interrupts, + * so if we miss here, then better luck next time. + */ + if (!spin_trylock(&trace_cmdline_lock)) + return; + + idx = map_pid_to_cmdline[tsk->pid]; + if (idx >= SAVED_CMDLINES) { + idx = (cmdline_idx + 1) % SAVED_CMDLINES; + + map = map_cmdline_to_pid[idx]; + if (map <= PID_MAX_DEFAULT) + map_pid_to_cmdline[map] = (unsigned)-1; + + map_pid_to_cmdline[tsk->pid] = idx; + + cmdline_idx = idx; + } + + memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); + + spin_unlock(&trace_cmdline_lock); +} + +static char *trace_find_cmdline(int pid) +{ + char *cmdline = "<...>"; + unsigned map; + + if (!pid) + return "<idle>"; + + if (pid > PID_MAX_DEFAULT) + goto out; + + map = map_pid_to_cmdline[pid]; + if (map >= SAVED_CMDLINES) + goto out; + + cmdline = saved_cmdlines[map]; + + out: + return cmdline; +} + +void tracing_record_cmdline(struct task_struct *tsk) +{ + if (atomic_read(&trace_record_cmdline_disabled)) + return; + + trace_save_cmdline(tsk); +} + +static inline struct list_head * +trace_next_list(struct trace_array_cpu *data, struct list_head *next) +{ + /* + * Roundrobin - but skip the head (which is not a real page): + */ + next = next->next; + if (unlikely(next == &data->trace_pages)) + next = next->next; + BUG_ON(next == &data->trace_pages); + + return next; +} + +static inline void * +trace_next_page(struct trace_array_cpu *data, void *addr) +{ + struct list_head *next; + struct page *page; + + page = virt_to_page(addr); + + next = trace_next_list(data, &page->lru); + page = list_entry(next, struct page, lru); + + return page_address(page); +} + +static inline struct trace_entry * +tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) +{ + unsigned long idx, idx_next; + struct trace_entry *entry; + + data->trace_idx++; + idx = data->trace_head_idx; + idx_next = idx + 1; + + BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); + + entry = data->trace_head + idx * TRACE_ENTRY_SIZE; + + if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { + data->trace_head = trace_next_page(data, data->trace_head); + idx_next = 0; + } + + if (data->trace_head == data->trace_tail && + idx_next == data->trace_tail_idx) { + /* overrun */ + data->overrun++; + data->trace_tail_idx++; + if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { + data->trace_tail = + trace_next_page(data, data->trace_tail); + data->trace_tail_idx = 0; + } + } + + data->trace_head_idx = idx_next; + + return entry; +} + +static inline void +tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) +{ + struct task_struct *tsk = current; + unsigned long pc; + + pc = preempt_count(); + + entry->preempt_count = pc & 0xff; + entry->pid = (tsk) ? tsk->pid : 0; + entry->t = ftrace_now(raw_smp_processor_id()); + entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | + ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | + ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | + (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); +} + +void +trace_function(struct trace_array *tr, struct trace_array_cpu *data, + unsigned long ip, unsigned long parent_ip, unsigned long flags) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, flags); + entry->type = TRACE_FN; + entry->fn.ip = ip; + entry->fn.parent_ip = parent_ip; + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); +} + +void +ftrace(struct trace_array *tr, struct trace_array_cpu *data, + unsigned long ip, unsigned long parent_ip, unsigned long flags) +{ + if (likely(!atomic_read(&data->disabled))) + trace_function(tr, data, ip, parent_ip, flags); +} + +#ifdef CONFIG_MMIOTRACE +void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, + struct mmiotrace_rw *rw) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_RW; + entry->mmiorw = *rw; + + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} + +void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, + struct mmiotrace_map *map) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_MAP; + entry->mmiomap = *map; + + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} +#endif + +void __trace_stack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags, + int skip) +{ + struct trace_entry *entry; + struct stack_trace trace; + + if (!(trace_flags & TRACE_ITER_STACKTRACE)) + return; + + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, flags); + entry->type = TRACE_STACK; + + memset(&entry->stack, 0, sizeof(entry->stack)); + + trace.nr_entries = 0; + trace.max_entries = FTRACE_STACK_ENTRIES; + trace.skip = skip; + trace.entries = entry->stack.caller; + + save_stack_trace(&trace); +} + +void +__trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + struct trace_array_cpu *data = __data; + struct trace_array *tr = __tr; + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_SPECIAL; + entry->special.arg1 = arg1; + entry->special.arg2 = arg2; + entry->special.arg3 = arg3; + __trace_stack(tr, data, irq_flags, 4); + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} + +void +tracing_sched_switch_trace(struct trace_array *tr, + struct trace_array_cpu *data, + struct task_struct *prev, + struct task_struct *next, + unsigned long flags) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, flags); + entry->type = TRACE_CTX; + entry->ctx.prev_pid = prev->pid; + entry->ctx.prev_prio = prev->prio; + entry->ctx.prev_state = prev->state; + entry->ctx.next_pid = next->pid; + entry->ctx.next_prio = next->prio; + entry->ctx.next_state = next->state; + __trace_stack(tr, data, flags, 5); + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); +} + +void +tracing_sched_wakeup_trace(struct trace_array *tr, + struct trace_array_cpu *data, + struct task_struct *wakee, + struct task_struct *curr, + unsigned long flags) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + raw_local_irq_save(irq_flags); + __raw_spin_lock(&data->lock); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, flags); + entry->type = TRACE_WAKE; + entry->ctx.prev_pid = curr->pid; + entry->ctx.prev_prio = curr->prio; + entry->ctx.prev_state = curr->state; + entry->ctx.next_pid = wakee->pid; + entry->ctx.next_prio = wakee->prio; + entry->ctx.next_state = wakee->state; + __trace_stack(tr, data, flags, 6); + __raw_spin_unlock(&data->lock); + raw_local_irq_restore(irq_flags); + + trace_wake_up(); +} + +void +ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl) + return; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + __trace_special(tr, data, arg1, arg2, arg3); + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +#ifdef CONFIG_FTRACE +static void +function_trace_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + if (unlikely(!ftrace_function_enabled)) + return; + + if (skip_trace(ip)) + return; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + trace_function(tr, data, ip, parent_ip, flags); + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = function_trace_call, +}; + +void tracing_start_function_trace(void) +{ + ftrace_function_enabled = 0; + register_ftrace_function(&trace_ops); + if (tracer_enabled) + ftrace_function_enabled = 1; +} + +void tracing_stop_function_trace(void) +{ + ftrace_function_enabled = 0; + unregister_ftrace_function(&trace_ops); +} +#endif + +enum trace_file_type { + TRACE_FILE_LAT_FMT = 1, +}; + +static struct trace_entry * +trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, + struct trace_iterator *iter, int cpu) +{ + struct page *page; + struct trace_entry *array; + + if (iter->next_idx[cpu] >= tr->entries || + iter->next_idx[cpu] >= data->trace_idx || + (data->trace_head == data->trace_tail && + data->trace_head_idx == data->trace_tail_idx)) + return NULL; + + if (!iter->next_page[cpu]) { + /* Initialize the iterator for this cpu trace buffer */ + WARN_ON(!data->trace_tail); + page = virt_to_page(data->trace_tail); + iter->next_page[cpu] = &page->lru; + iter->next_page_idx[cpu] = data->trace_tail_idx; + } + + page = list_entry(iter->next_page[cpu], struct page, lru); + BUG_ON(&data->trace_pages == &page->lru); + + array = page_address(page); + + WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); + return &array[iter->next_page_idx[cpu]]; +} + +static struct trace_entry * +find_next_entry(struct trace_iterator *iter, int *ent_cpu) +{ + struct trace_array *tr = iter->tr; + struct trace_entry *ent, *next = NULL; + int next_cpu = -1; + int cpu; + + for_each_tracing_cpu(cpu) { + if (!head_page(tr->data[cpu])) + continue; + ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + /* + * Pick the entry with the smallest timestamp: + */ + if (ent && (!next || ent->t < next->t)) { + next = ent; + next_cpu = cpu; + } + } + + if (ent_cpu) + *ent_cpu = next_cpu; + + return next; +} + +static void trace_iterator_increment(struct trace_iterator *iter) +{ + iter->idx++; + iter->next_idx[iter->cpu]++; + iter->next_page_idx[iter->cpu]++; + + if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { + struct trace_array_cpu *data = iter->tr->data[iter->cpu]; + + iter->next_page_idx[iter->cpu] = 0; + iter->next_page[iter->cpu] = + trace_next_list(data, iter->next_page[iter->cpu]); + } +} + +static void trace_consume(struct trace_iterator *iter) +{ + struct trace_array_cpu *data = iter->tr->data[iter->cpu]; + + data->trace_tail_idx++; + if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { + data->trace_tail = trace_next_page(data, data->trace_tail); + data->trace_tail_idx = 0; + } + + /* Check if we empty it, then reset the index */ + if (data->trace_head == data->trace_tail && + data->trace_head_idx == data->trace_tail_idx) + data->trace_idx = 0; +} + +static void *find_next_entry_inc(struct trace_iterator *iter) +{ + struct trace_entry *next; + int next_cpu = -1; + + next = find_next_entry(iter, &next_cpu); + + iter->prev_ent = iter->ent; + iter->prev_cpu = iter->cpu; + + iter->ent = next; + iter->cpu = next_cpu; + + if (next) + trace_iterator_increment(iter); + + return next ? iter : NULL; +} + +static void *s_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct trace_iterator *iter = m->private; + int i = (int)*pos; + void *ent; + + (*pos)++; + + /* can't go backwards */ + if (iter->idx > i) + return NULL; + + if (iter->idx < 0) + ent = find_next_entry_inc(iter); + else + ent = iter; + + while (ent && iter->idx < i) + ent = find_next_entry_inc(iter); + + iter->pos = *pos; + + return ent; +} + +static void *s_start(struct seq_file *m, loff_t *pos) +{ + struct trace_iterator *iter = m->private; + void *p = NULL; + loff_t l = 0; + int i; + + mutex_lock(&trace_types_lock); + + if (!current_trace || current_trace != iter->trace) { + mutex_unlock(&trace_types_lock); + return NULL; + } + + atomic_inc(&trace_record_cmdline_disabled); + + /* let the tracer grab locks here if needed */ + if (current_trace->start) + current_trace->start(iter); + + if (*pos != iter->pos) { + iter->ent = NULL; + iter->cpu = 0; + iter->idx = -1; + iter->prev_ent = NULL; + iter->prev_cpu = -1; + + for_each_tracing_cpu(i) { + iter->next_idx[i] = 0; + iter->next_page[i] = NULL; + } + + for (p = iter; p && l < *pos; p = s_next(m, p, &l)) + ; + + } else { + l = *pos - 1; + p = s_next(m, p, &l); + } + + return p; +} + +static void s_stop(struct seq_file *m, void *p) +{ + struct trace_iterator *iter = m->private; + + atomic_dec(&trace_record_cmdline_disabled); + + /* let the tracer release locks here if needed */ + if (current_trace && current_trace == iter->trace && iter->trace->stop) + iter->trace->stop(iter); + + mutex_unlock(&trace_types_lock); +} + +#define KRETPROBE_MSG "[unknown/kretprobe'd]" + +#ifdef CONFIG_KRETPROBES +static inline int kretprobed(unsigned long addr) +{ + return addr == (unsigned long)kretprobe_trampoline; +} +#else +static inline int kretprobed(unsigned long addr) +{ + return 0; +} +#endif /* CONFIG_KRETPROBES */ + +static int +seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) +{ +#ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; + + kallsyms_lookup(address, NULL, NULL, NULL, str); + + return trace_seq_printf(s, fmt, str); +#endif + return 1; +} + +static int +seq_print_sym_offset(struct trace_seq *s, const char *fmt, + unsigned long address) +{ +#ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; + + sprint_symbol(str, address); + return trace_seq_printf(s, fmt, str); +#endif + return 1; +} + +#ifndef CONFIG_64BIT +# define IP_FMT "%08lx" +#else +# define IP_FMT "%016lx" +#endif + +static int +seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) +{ + int ret; + + if (!ip) + return trace_seq_printf(s, "0"); + + if (sym_flags & TRACE_ITER_SYM_OFFSET) + ret = seq_print_sym_offset(s, "%s", ip); + else + ret = seq_print_sym_short(s, "%s", ip); + + if (!ret) + return 0; + + if (sym_flags & TRACE_ITER_SYM_ADDR) + ret = trace_seq_printf(s, " <" IP_FMT ">", ip); + return ret; +} + +static void print_lat_help_header(struct seq_file *m) +{ + seq_puts(m, "# _------=> CPU# \n"); + seq_puts(m, "# / _-----=> irqs-off \n"); + seq_puts(m, "# | / _----=> need-resched \n"); + seq_puts(m, "# || / _---=> hardirq/softirq \n"); + seq_puts(m, "# ||| / _--=> preempt-depth \n"); + seq_puts(m, "# |||| / \n"); + seq_puts(m, "# ||||| delay \n"); + seq_puts(m, "# cmd pid ||||| time | caller \n"); + seq_puts(m, "# \\ / ||||| \\ | / \n"); +} + +static void print_func_help_header(struct seq_file *m) +{ + seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | | |\n"); +} + + +static void +print_trace_header(struct seq_file *m, struct trace_iterator *iter) +{ + unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); + struct trace_array *tr = iter->tr; + struct trace_array_cpu *data = tr->data[tr->cpu]; + struct tracer *type = current_trace; + unsigned long total = 0; + unsigned long entries = 0; + int cpu; + const char *name = "preemption"; + + if (type) + name = type->name; + + for_each_tracing_cpu(cpu) { + if (head_page(tr->data[cpu])) { + total += tr->data[cpu]->trace_idx; + if (tr->data[cpu]->trace_idx > tr->entries) + entries += tr->entries; + else + entries += tr->data[cpu]->trace_idx; + } + } + + seq_printf(m, "%s latency trace v1.1.5 on %s\n", + name, UTS_RELEASE); + seq_puts(m, "-----------------------------------" + "---------------------------------\n"); + seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" + " (M:%s VP:%d, KP:%d, SP:%d HP:%d", + nsecs_to_usecs(data->saved_latency), + entries, + total, + tr->cpu, +#if defined(CONFIG_PREEMPT_NONE) + "server", +#elif defined(CONFIG_PREEMPT_VOLUNTARY) + "desktop", +#elif defined(CONFIG_PREEMPT) + "preempt", +#else + "unknown", +#endif + /* These are reserved for later use */ + 0, 0, 0, 0); +#ifdef CONFIG_SMP + seq_printf(m, " #P:%d)\n", num_online_cpus()); +#else + seq_puts(m, ")\n"); +#endif + seq_puts(m, " -----------------\n"); + seq_printf(m, " | task: %.16s-%d " + "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", + data->comm, data->pid, data->uid, data->nice, + data->policy, data->rt_priority); + seq_puts(m, " -----------------\n"); + + if (data->critical_start) { + seq_puts(m, " => started at: "); + seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); + trace_print_seq(m, &iter->seq); + seq_puts(m, "\n => ended at: "); + seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); + trace_print_seq(m, &iter->seq); + seq_puts(m, "\n"); + } + + seq_puts(m, "\n"); +} + +static void +lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) +{ + int hardirq, softirq; + char *comm; + + comm = trace_find_cmdline(entry->pid); + + trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); + trace_seq_printf(s, "%d", cpu); + trace_seq_printf(s, "%c%c", + (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', + ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); + + hardirq = entry->flags & TRACE_FLAG_HARDIRQ; + softirq = entry->flags & TRACE_FLAG_SOFTIRQ; + if (hardirq && softirq) { + trace_seq_putc(s, 'H'); + } else { + if (hardirq) { + trace_seq_putc(s, 'h'); + } else { + if (softirq) + trace_seq_putc(s, 's'); + else + trace_seq_putc(s, '.'); + } + } + + if (entry->preempt_count) + trace_seq_printf(s, "%x", entry->preempt_count); + else + trace_seq_puts(s, "."); +} + +unsigned long preempt_mark_thresh = 100; + +static void +lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, + unsigned long rel_usecs) +{ + trace_seq_printf(s, " %4lldus", abs_usecs); + if (rel_usecs > preempt_mark_thresh) + trace_seq_puts(s, "!: "); + else if (rel_usecs > 1) + trace_seq_puts(s, "+: "); + else + trace_seq_puts(s, " : "); +} + +static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; + +static int +print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) +{ + struct trace_seq *s = &iter->seq; + unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); + struct trace_entry *next_entry = find_next_entry(iter, NULL); + unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); + struct trace_entry *entry = iter->ent; + unsigned long abs_usecs; + unsigned long rel_usecs; + char *comm; + int S, T; + int i; + unsigned state; + + if (!next_entry) + next_entry = entry; + rel_usecs = ns2usecs(next_entry->t - entry->t); + abs_usecs = ns2usecs(entry->t - iter->tr->time_start); + + if (verbose) { + comm = trace_find_cmdline(entry->pid); + trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" + " %ld.%03ldms (+%ld.%03ldms): ", + comm, + entry->pid, cpu, entry->flags, + entry->preempt_count, trace_idx, + ns2usecs(entry->t), + abs_usecs/1000, + abs_usecs % 1000, rel_usecs/1000, + rel_usecs % 1000); + } else { + lat_print_generic(s, entry, cpu); + lat_print_timestamp(s, abs_usecs, rel_usecs); + } + switch (entry->type) { + case TRACE_FN: + seq_print_ip_sym(s, entry->fn.ip, sym_flags); + trace_seq_puts(s, " ("); + if (kretprobed(entry->fn.parent_ip)) + trace_seq_puts(s, KRETPROBE_MSG); + else + seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); + trace_seq_puts(s, ")\n"); + break; + case TRACE_CTX: + case TRACE_WAKE: + T = entry->ctx.next_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.next_state] : 'X'; + + state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0; + S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X'; + comm = trace_find_cmdline(entry->ctx.next_pid); + trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n", + entry->ctx.prev_pid, + entry->ctx.prev_prio, + S, entry->type == TRACE_CTX ? "==>" : " +", + entry->ctx.next_pid, + entry->ctx.next_prio, + T, comm); + break; + case TRACE_SPECIAL: + trace_seq_printf(s, "# %ld %ld %ld\n", + entry->special.arg1, + entry->special.arg2, + entry->special.arg3); + break; + case TRACE_STACK: + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { + if (i) + trace_seq_puts(s, " <= "); + seq_print_ip_sym(s, entry->stack.caller[i], sym_flags); + } + trace_seq_puts(s, "\n"); + break; + default: + trace_seq_printf(s, "Unknown type %d\n", entry->type); + } + return 1; +} + +static int print_trace_fmt(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); + struct trace_entry *entry; + unsigned long usec_rem; + unsigned long long t; + unsigned long secs; + char *comm; + int ret; + int S, T; + int i; + + entry = iter->ent; + + comm = trace_find_cmdline(iter->ent->pid); + + t = ns2usecs(entry->t); + usec_rem = do_div(t, 1000000ULL); + secs = (unsigned long)t; + + ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); + if (!ret) + return 0; + ret = trace_seq_printf(s, "[%02d] ", iter->cpu); + if (!ret) + return 0; + ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); + if (!ret) + return 0; + + switch (entry->type) { + case TRACE_FN: + ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); + if (!ret) + return 0; + if ((sym_flags & TRACE_ITER_PRINT_PARENT) && + entry->fn.parent_ip) { + ret = trace_seq_printf(s, " <-"); + if (!ret) + return 0; + if (kretprobed(entry->fn.parent_ip)) + ret = trace_seq_puts(s, KRETPROBE_MSG); + else + ret = seq_print_ip_sym(s, entry->fn.parent_ip, + sym_flags); + if (!ret) + return 0; + } + ret = trace_seq_printf(s, "\n"); + if (!ret) + return 0; + break; + case TRACE_CTX: + case TRACE_WAKE: + S = entry->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.prev_state] : 'X'; + T = entry->ctx.next_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.next_state] : 'X'; + ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n", + entry->ctx.prev_pid, + entry->ctx.prev_prio, + S, + entry->type == TRACE_CTX ? "==>" : " +", + entry->ctx.next_pid, + entry->ctx.next_prio, + T); + if (!ret) + return 0; + break; + case TRACE_SPECIAL: + ret = trace_seq_printf(s, "# %ld %ld %ld\n", + entry->special.arg1, + entry->special.arg2, + entry->special.arg3); + if (!ret) + return 0; + break; + case TRACE_STACK: + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { + if (i) { + ret = trace_seq_puts(s, " <= "); + if (!ret) + return 0; + } + ret = seq_print_ip_sym(s, entry->stack.caller[i], + sym_flags); + if (!ret) + return 0; + } + ret = trace_seq_puts(s, "\n"); + if (!ret) + return 0; + break; + } + return 1; +} + +static int print_raw_fmt(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry; + int ret; + int S, T; + + entry = iter->ent; + + ret = trace_seq_printf(s, "%d %d %llu ", + entry->pid, iter->cpu, entry->t); + if (!ret) + return 0; + + switch (entry->type) { + case TRACE_FN: + ret = trace_seq_printf(s, "%x %x\n", + entry->fn.ip, entry->fn.parent_ip); + if (!ret) + return 0; + break; + case TRACE_CTX: + case TRACE_WAKE: + S = entry->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.prev_state] : 'X'; + T = entry->ctx.next_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.next_state] : 'X'; + if (entry->type == TRACE_WAKE) + S = '+'; + ret = trace_seq_printf(s, "%d %d %c %d %d %c\n", + entry->ctx.prev_pid, + entry->ctx.prev_prio, + S, + entry->ctx.next_pid, + entry->ctx.next_prio, + T); + if (!ret) + return 0; + break; + case TRACE_SPECIAL: + case TRACE_STACK: + ret = trace_seq_printf(s, "# %ld %ld %ld\n", + entry->special.arg1, + entry->special.arg2, + entry->special.arg3); + if (!ret) + return 0; + break; + } + return 1; +} + +#define SEQ_PUT_FIELD_RET(s, x) \ +do { \ + if (!trace_seq_putmem(s, &(x), sizeof(x))) \ + return 0; \ +} while (0) + +#define SEQ_PUT_HEX_FIELD_RET(s, x) \ +do { \ + if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \ + return 0; \ +} while (0) + +static int print_hex_fmt(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + unsigned char newline = '\n'; + struct trace_entry *entry; + int S, T; + + entry = iter->ent; + + SEQ_PUT_HEX_FIELD_RET(s, entry->pid); + SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); + SEQ_PUT_HEX_FIELD_RET(s, entry->t); + + switch (entry->type) { + case TRACE_FN: + SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip); + SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + break; + case TRACE_CTX: + case TRACE_WAKE: + S = entry->ctx.prev_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.prev_state] : 'X'; + T = entry->ctx.next_state < sizeof(state_to_char) ? + state_to_char[entry->ctx.next_state] : 'X'; + if (entry->type == TRACE_WAKE) + S = '+'; + SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid); + SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio); + SEQ_PUT_HEX_FIELD_RET(s, S); + SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid); + SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio); + SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + SEQ_PUT_HEX_FIELD_RET(s, T); + break; + case TRACE_SPECIAL: + case TRACE_STACK: + SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1); + SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2); + SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3); + break; + } + SEQ_PUT_FIELD_RET(s, newline); + + return 1; +} + +static int print_bin_fmt(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry; + + entry = iter->ent; + + SEQ_PUT_FIELD_RET(s, entry->pid); + SEQ_PUT_FIELD_RET(s, entry->cpu); + SEQ_PUT_FIELD_RET(s, entry->t); + + switch (entry->type) { + case TRACE_FN: + SEQ_PUT_FIELD_RET(s, entry->fn.ip); + SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip); + break; + case TRACE_CTX: + SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid); + SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio); + SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state); + SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid); + SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio); + SEQ_PUT_FIELD_RET(s, entry->ctx.next_state); + break; + case TRACE_SPECIAL: + case TRACE_STACK: + SEQ_PUT_FIELD_RET(s, entry->special.arg1); + SEQ_PUT_FIELD_RET(s, entry->special.arg2); + SEQ_PUT_FIELD_RET(s, entry->special.arg3); + break; + } + return 1; +} + +static int trace_empty(struct trace_iterator *iter) +{ + struct trace_array_cpu *data; + int cpu; + + for_each_tracing_cpu(cpu) { + data = iter->tr->data[cpu]; + + if (head_page(data) && data->trace_idx && + (data->trace_tail != data->trace_head || + data->trace_tail_idx != data->trace_head_idx)) + return 0; + } + return 1; +} + +static int print_trace_line(struct trace_iterator *iter) +{ + if (iter->trace && iter->trace->print_line) + return iter->trace->print_line(iter); + + if (trace_flags & TRACE_ITER_BIN) + return print_bin_fmt(iter); + + if (trace_flags & TRACE_ITER_HEX) + return print_hex_fmt(iter); + + if (trace_flags & TRACE_ITER_RAW) + return print_raw_fmt(iter); + + if (iter->iter_flags & TRACE_FILE_LAT_FMT) + return print_lat_fmt(iter, iter->idx, iter->cpu); + + return print_trace_fmt(iter); +} + +static int s_show(struct seq_file *m, void *v) +{ + struct trace_iterator *iter = v; + + if (iter->ent == NULL) { + if (iter->tr) { + seq_printf(m, "# tracer: %s\n", iter->trace->name); + seq_puts(m, "#\n"); + } + if (iter->iter_flags & TRACE_FILE_LAT_FMT) { + /* print nothing if the buffers are empty */ + if (trace_empty(iter)) + return 0; + print_trace_header(m, iter); + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_lat_help_header(m); + } else { + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_func_help_header(m); + } + } else { + print_trace_line(iter); + trace_print_seq(m, &iter->seq); + } + + return 0; +} + +static struct seq_operations tracer_seq_ops = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static struct trace_iterator * +__tracing_open(struct inode *inode, struct file *file, int *ret) +{ + struct trace_iterator *iter; + + if (tracing_disabled) { + *ret = -ENODEV; + return NULL; + } + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) { + *ret = -ENOMEM; + goto out; + } + + mutex_lock(&trace_types_lock); + if (current_trace && current_trace->print_max) + iter->tr = &max_tr; + else + iter->tr = inode->i_private; + iter->trace = current_trace; + iter->pos = -1; + + /* TODO stop tracer */ + *ret = seq_open(file, &tracer_seq_ops); + if (!*ret) { + struct seq_file *m = file->private_data; + m->private = iter; + + /* stop the trace while dumping */ + if (iter->tr->ctrl) { + tracer_enabled = 0; + ftrace_function_enabled = 0; + } + + if (iter->trace && iter->trace->open) + iter->trace->open(iter); + } else { + kfree(iter); + iter = NULL; + } + mutex_unlock(&trace_types_lock); + + out: + return iter; +} + +int tracing_open_generic(struct inode *inode, struct file *filp) +{ + if (tracing_disabled) + return -ENODEV; + + filp->private_data = inode->i_private; + return 0; +} + +int tracing_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = (struct seq_file *)file->private_data; + struct trace_iterator *iter = m->private; + + mutex_lock(&trace_types_lock); + if (iter->trace && iter->trace->close) + iter->trace->close(iter); + + /* reenable tracing if it was previously enabled */ + if (iter->tr->ctrl) { + tracer_enabled = 1; + /* + * It is safe to enable function tracing even if it + * isn't used + */ + ftrace_function_enabled = 1; + } + mutex_unlock(&trace_types_lock); + + seq_release(inode, file); + kfree(iter); + return 0; +} + +static int tracing_open(struct inode *inode, struct file *file) +{ + int ret; + + __tracing_open(inode, file, &ret); + + return ret; +} + +static int tracing_lt_open(struct inode *inode, struct file *file) +{ + struct trace_iterator *iter; + int ret; + + iter = __tracing_open(inode, file, &ret); + + if (!ret) + iter->iter_flags |= TRACE_FILE_LAT_FMT; + + return ret; +} + + +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct tracer *t = m->private; + + (*pos)++; + + if (t) + t = t->next; + + m->private = t; + + return t; +} + +static void *t_start(struct seq_file *m, loff_t *pos) +{ + struct tracer *t = m->private; + loff_t l = 0; + + mutex_lock(&trace_types_lock); + for (; t && l < *pos; t = t_next(m, t, &l)) + ; + + return t; +} + +static void t_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&trace_types_lock); +} + +static int t_show(struct seq_file *m, void *v) +{ + struct tracer *t = v; + + if (!t) + return 0; + + seq_printf(m, "%s", t->name); + if (t->next) + seq_putc(m, ' '); + else + seq_putc(m, '\n'); + + return 0; +} + +static struct seq_operations show_traces_seq_ops = { + .start = t_start, + .next = t_next, + .stop = t_stop, + .show = t_show, +}; + +static int show_traces_open(struct inode *inode, struct file *file) +{ + int ret; + + if (tracing_disabled) + return -ENODEV; + + ret = seq_open(file, &show_traces_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = trace_types; + } + + return ret; +} + +static struct file_operations tracing_fops = { + .open = tracing_open, + .read = seq_read, + .llseek = seq_lseek, + .release = tracing_release, +}; + +static struct file_operations tracing_lt_fops = { + .open = tracing_lt_open, + .read = seq_read, + .llseek = seq_lseek, + .release = tracing_release, +}; + +static struct file_operations show_traces_fops = { + .open = show_traces_open, + .read = seq_read, + .release = seq_release, +}; + +/* + * Only trace on a CPU if the bitmask is set: + */ +static cpumask_t tracing_cpumask = CPU_MASK_ALL; + +/* + * When tracing/tracing_cpu_mask is modified then this holds + * the new bitmask we are about to install: + */ +static cpumask_t tracing_cpumask_new; + +/* + * The tracer itself will not take this lock, but still we want + * to provide a consistent cpumask to user-space: + */ +static DEFINE_MUTEX(tracing_cpumask_update_lock); + +/* + * Temporary storage for the character representation of the + * CPU bitmask (and one more byte for the newline): + */ +static char mask_str[NR_CPUS + 1]; + +static ssize_t +tracing_cpumask_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + int len; + + mutex_lock(&tracing_cpumask_update_lock); + + len = cpumask_scnprintf(mask_str, count, tracing_cpumask); + if (count - len < 2) { + count = -EINVAL; + goto out_err; + } + len += sprintf(mask_str + len, "\n"); + count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); + +out_err: + mutex_unlock(&tracing_cpumask_update_lock); + + return count; +} + +static ssize_t +tracing_cpumask_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + int err, cpu; + + mutex_lock(&tracing_cpumask_update_lock); + err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); + if (err) + goto err_unlock; + + raw_local_irq_disable(); + __raw_spin_lock(&ftrace_max_lock); + for_each_tracing_cpu(cpu) { + /* + * Increase/decrease the disabled counter if we are + * about to flip a bit in the cpumask: + */ + if (cpu_isset(cpu, tracing_cpumask) && + !cpu_isset(cpu, tracing_cpumask_new)) { + atomic_inc(&global_trace.data[cpu]->disabled); + } + if (!cpu_isset(cpu, tracing_cpumask) && + cpu_isset(cpu, tracing_cpumask_new)) { + atomic_dec(&global_trace.data[cpu]->disabled); + } + } + __raw_spin_unlock(&ftrace_max_lock); + raw_local_irq_enable(); + + tracing_cpumask = tracing_cpumask_new; + + mutex_unlock(&tracing_cpumask_update_lock); + + return count; + +err_unlock: + mutex_unlock(&tracing_cpumask_update_lock); + + return err; +} + +static struct file_operations tracing_cpumask_fops = { + .open = tracing_open_generic, + .read = tracing_cpumask_read, + .write = tracing_cpumask_write, +}; + +static ssize_t +tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char *buf; + int r = 0; + int len = 0; + int i; + + /* calulate max size */ + for (i = 0; trace_options[i]; i++) { + len += strlen(trace_options[i]); + len += 3; /* "no" and space */ + } + + /* +2 for \n and \0 */ + buf = kmalloc(len + 2, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + for (i = 0; trace_options[i]; i++) { + if (trace_flags & (1 << i)) + r += sprintf(buf + r, "%s ", trace_options[i]); + else + r += sprintf(buf + r, "no%s ", trace_options[i]); + } + + r += sprintf(buf + r, "\n"); + WARN_ON(r >= len + 2); + + r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); + + kfree(buf); + + return r; +} + +static ssize_t +tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[64]; + char *cmp = buf; + int neg = 0; + int i; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + if (strncmp(buf, "no", 2) == 0) { + neg = 1; + cmp += 2; + } + + for (i = 0; trace_options[i]; i++) { + int len = strlen(trace_options[i]); + + if (strncmp(cmp, trace_options[i], len) == 0) { + if (neg) + trace_flags &= ~(1 << i); + else + trace_flags |= (1 << i); + break; + } + } + /* + * If no option could be set, return an error: + */ + if (!trace_options[i]) + return -EINVAL; + + filp->f_pos += cnt; + + return cnt; +} + +static struct file_operations tracing_iter_fops = { + .open = tracing_open_generic, + .read = tracing_iter_ctrl_read, + .write = tracing_iter_ctrl_write, +}; + +static const char readme_msg[] = + "tracing mini-HOWTO:\n\n" + "# mkdir /debug\n" + "# mount -t debugfs nodev /debug\n\n" + "# cat /debug/tracing/available_tracers\n" + "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" + "# cat /debug/tracing/current_tracer\n" + "none\n" + "# echo sched_switch > /debug/tracing/current_tracer\n" + "# cat /debug/tracing/current_tracer\n" + "sched_switch\n" + "# cat /debug/tracing/iter_ctrl\n" + "noprint-parent nosym-offset nosym-addr noverbose\n" + "# echo print-parent > /debug/tracing/iter_ctrl\n" + "# echo 1 > /debug/tracing/tracing_enabled\n" + "# cat /debug/tracing/trace > /tmp/trace.txt\n" + "echo 0 > /debug/tracing/tracing_enabled\n" +; + +static ssize_t +tracing_readme_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_read_from_buffer(ubuf, cnt, ppos, + readme_msg, strlen(readme_msg)); +} + +static struct file_operations tracing_readme_fops = { + .open = tracing_open_generic, + .read = tracing_readme_read, +}; + +static ssize_t +tracing_ctrl_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + char buf[64]; + int r; + + r = sprintf(buf, "%ld\n", tr->ctrl); + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +tracing_ctrl_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + char buf[64]; + long val; + int ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + val = !!val; + + mutex_lock(&trace_types_lock); + if (tr->ctrl ^ val) { + if (val) + tracer_enabled = 1; + else + tracer_enabled = 0; + + tr->ctrl = val; + + if (current_trace && current_trace->ctrl_update) + current_trace->ctrl_update(tr); + } + mutex_unlock(&trace_types_lock); + + filp->f_pos += cnt; + + return cnt; +} + +static ssize_t +tracing_set_trace_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[max_tracer_type_len+2]; + int r; + + mutex_lock(&trace_types_lock); + if (current_trace) + r = sprintf(buf, "%s\n", current_trace->name); + else + r = sprintf(buf, "\n"); + mutex_unlock(&trace_types_lock); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +tracing_set_trace_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = &global_trace; + struct tracer *t; + char buf[max_tracer_type_len+1]; + int i; + + if (cnt > max_tracer_type_len) + cnt = max_tracer_type_len; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + /* strip ending whitespace. */ + for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) + buf[i] = 0; + + mutex_lock(&trace_types_lock); + for (t = trace_types; t; t = t->next) { + if (strcmp(t->name, buf) == 0) + break; + } + if (!t || t == current_trace) + goto out; + + if (current_trace && current_trace->reset) + current_trace->reset(tr); + + current_trace = t; + if (t->init) + t->init(tr); + + out: + mutex_unlock(&trace_types_lock); + + filp->f_pos += cnt; + + return cnt; +} + +static ssize_t +tracing_max_lat_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long *ptr = filp->private_data; + char buf[64]; + int r; + + r = snprintf(buf, sizeof(buf), "%ld\n", + *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); + if (r > sizeof(buf)) + r = sizeof(buf); + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +tracing_max_lat_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long *ptr = filp->private_data; + char buf[64]; + long val; + int ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + *ptr = val * 1000; + + return cnt; +} + +static atomic_t tracing_reader; + +static int tracing_open_pipe(struct inode *inode, struct file *filp) +{ + struct trace_iterator *iter; + + if (tracing_disabled) + return -ENODEV; + + /* We only allow for reader of the pipe */ + if (atomic_inc_return(&tracing_reader) != 1) { + atomic_dec(&tracing_reader); + return -EBUSY; + } + + /* create a buffer to store the information to pass to userspace */ + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return -ENOMEM; + + mutex_lock(&trace_types_lock); + iter->tr = &global_trace; + iter->trace = current_trace; + filp->private_data = iter; + + if (iter->trace->pipe_open) + iter->trace->pipe_open(iter); + mutex_unlock(&trace_types_lock); + + return 0; +} + +static int tracing_release_pipe(struct inode *inode, struct file *file) +{ + struct trace_iterator *iter = file->private_data; + + kfree(iter); + atomic_dec(&tracing_reader); + + return 0; +} + +static unsigned int +tracing_poll_pipe(struct file *filp, poll_table *poll_table) +{ + struct trace_iterator *iter = filp->private_data; + + if (trace_flags & TRACE_ITER_BLOCK) { + /* + * Always select as readable when in blocking mode + */ + return POLLIN | POLLRDNORM; + } else { + if (!trace_empty(iter)) + return POLLIN | POLLRDNORM; + poll_wait(filp, &trace_wait, poll_table); + if (!trace_empty(iter)) + return POLLIN | POLLRDNORM; + + return 0; + } +} + +/* + * Consumer reader. + */ +static ssize_t +tracing_read_pipe(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_iterator *iter = filp->private_data; + struct trace_array_cpu *data; + static cpumask_t mask; + unsigned long flags; +#ifdef CONFIG_FTRACE + int ftrace_save; +#endif + int cpu; + ssize_t sret; + + /* return any leftover data */ + sret = trace_seq_to_user(&iter->seq, ubuf, cnt); + if (sret != -EBUSY) + return sret; + sret = 0; + + trace_seq_reset(&iter->seq); + + mutex_lock(&trace_types_lock); + if (iter->trace->read) { + sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); + if (sret) + goto out; + } + + while (trace_empty(iter)) { + + if ((filp->f_flags & O_NONBLOCK)) { + sret = -EAGAIN; + goto out; + } + + /* + * This is a make-shift waitqueue. The reason we don't use + * an actual wait queue is because: + * 1) we only ever have one waiter + * 2) the tracing, traces all functions, we don't want + * the overhead of calling wake_up and friends + * (and tracing them too) + * Anyway, this is really very primitive wakeup. + */ + set_current_state(TASK_INTERRUPTIBLE); + iter->tr->waiter = current; + + mutex_unlock(&trace_types_lock); + + /* sleep for 100 msecs, and try again. */ + schedule_timeout(HZ/10); + + mutex_lock(&trace_types_lock); + + iter->tr->waiter = NULL; + + if (signal_pending(current)) { + sret = -EINTR; + goto out; + } + + if (iter->trace != current_trace) + goto out; + + /* + * We block until we read something and tracing is disabled. + * We still block if tracing is disabled, but we have never + * read anything. This allows a user to cat this file, and + * then enable tracing. But after we have read something, + * we give an EOF when tracing is again disabled. + * + * iter->pos will be 0 if we haven't read anything. + */ + if (!tracer_enabled && iter->pos) + break; + + continue; + } + + /* stop when tracing is finished */ + if (trace_empty(iter)) + goto out; + + if (cnt >= PAGE_SIZE) + cnt = PAGE_SIZE - 1; + + /* reset all but tr, trace, and overruns */ + memset(&iter->seq, 0, + sizeof(struct trace_iterator) - + offsetof(struct trace_iterator, seq)); + iter->pos = -1; + + /* + * We need to stop all tracing on all CPUS to read the + * the next buffer. This is a bit expensive, but is + * not done often. We fill all what we can read, + * and then release the locks again. + */ + + cpus_clear(mask); + local_irq_save(flags); +#ifdef CONFIG_FTRACE + ftrace_save = ftrace_enabled; + ftrace_enabled = 0; +#endif + smp_wmb(); + for_each_tracing_cpu(cpu) { + data = iter->tr->data[cpu]; + + if (!head_page(data) || !data->trace_idx) + continue; + + atomic_inc(&data->disabled); + cpu_set(cpu, mask); + } + + for_each_cpu_mask(cpu, mask) { + data = iter->tr->data[cpu]; + __raw_spin_lock(&data->lock); + + if (data->overrun > iter->last_overrun[cpu]) + iter->overrun[cpu] += + data->overrun - iter->last_overrun[cpu]; + iter->last_overrun[cpu] = data->overrun; + } + + while (find_next_entry_inc(iter) != NULL) { + int ret; + int len = iter->seq.len; + + ret = print_trace_line(iter); + if (!ret) { + /* don't print partial lines */ + iter->seq.len = len; + break; + } + + trace_consume(iter); + + if (iter->seq.len >= cnt) + break; + } + + for_each_cpu_mask(cpu, mask) { + data = iter->tr->data[cpu]; + __raw_spin_unlock(&data->lock); + } + + for_each_cpu_mask(cpu, mask) { + data = iter->tr->data[cpu]; + atomic_dec(&data->disabled); + } +#ifdef CONFIG_FTRACE + ftrace_enabled = ftrace_save; +#endif + local_irq_restore(flags); + + /* Now copy what we have to the user */ + sret = trace_seq_to_user(&iter->seq, ubuf, cnt); + if (iter->seq.readpos >= iter->seq.len) + trace_seq_reset(&iter->seq); + if (sret == -EBUSY) + sret = 0; + +out: + mutex_unlock(&trace_types_lock); + + return sret; +} + +static ssize_t +tracing_entries_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + char buf[64]; + int r; + + r = sprintf(buf, "%lu\n", tr->entries); + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +tracing_entries_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long val; + char buf[64]; + int i, ret; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + /* must have at least 1 entry */ + if (!val) + return -EINVAL; + + mutex_lock(&trace_types_lock); + + if (current_trace != &no_tracer) { + cnt = -EBUSY; + pr_info("ftrace: set current_tracer to none" + " before modifying buffer size\n"); + goto out; + } + + if (val > global_trace.entries) { + long pages_requested; + unsigned long freeable_pages; + + /* make sure we have enough memory before mapping */ + pages_requested = + (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE; + + /* account for each buffer (and max_tr) */ + pages_requested *= tracing_nr_buffers * 2; + + /* Check for overflow */ + if (pages_requested < 0) { + cnt = -ENOMEM; + goto out; + } + + freeable_pages = determine_dirtyable_memory(); + + /* we only allow to request 1/4 of useable memory */ + if (pages_requested > + ((freeable_pages + tracing_pages_allocated) / 4)) { + cnt = -ENOMEM; + goto out; + } + + while (global_trace.entries < val) { + if (trace_alloc_page()) { + cnt = -ENOMEM; + goto out; + } + /* double check that we don't go over the known pages */ + if (tracing_pages_allocated > pages_requested) + break; + } + + } else { + /* include the number of entries in val (inc of page entries) */ + while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1)) + trace_free_page(); + } + + /* check integrity */ + for_each_tracing_cpu(i) + check_pages(global_trace.data[i]); + + filp->f_pos += cnt; + + /* If check pages failed, return ENOMEM */ + if (tracing_disabled) + cnt = -ENOMEM; + out: + max_tr.entries = global_trace.entries; + mutex_unlock(&trace_types_lock); + + return cnt; +} + +static struct file_operations tracing_max_lat_fops = { + .open = tracing_open_generic, + .read = tracing_max_lat_read, + .write = tracing_max_lat_write, +}; + +static struct file_operations tracing_ctrl_fops = { + .open = tracing_open_generic, + .read = tracing_ctrl_read, + .write = tracing_ctrl_write, +}; + +static struct file_operations set_tracer_fops = { + .open = tracing_open_generic, + .read = tracing_set_trace_read, + .write = tracing_set_trace_write, +}; + +static struct file_operations tracing_pipe_fops = { + .open = tracing_open_pipe, + .poll = tracing_poll_pipe, + .read = tracing_read_pipe, + .release = tracing_release_pipe, +}; + +static struct file_operations tracing_entries_fops = { + .open = tracing_open_generic, + .read = tracing_entries_read, + .write = tracing_entries_write, +}; + +#ifdef CONFIG_DYNAMIC_FTRACE + +static ssize_t +tracing_read_long(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long *p = filp->private_data; + char buf[64]; + int r; + + r = sprintf(buf, "%ld\n", *p); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static struct file_operations tracing_read_long_fops = { + .open = tracing_open_generic, + .read = tracing_read_long, +}; +#endif + +static struct dentry *d_tracer; + +struct dentry *tracing_init_dentry(void) +{ + static int once; + + if (d_tracer) + return d_tracer; + + d_tracer = debugfs_create_dir("tracing", NULL); + + if (!d_tracer && !once) { + once = 1; + pr_warning("Could not create debugfs directory 'tracing'\n"); + return NULL; + } + + return d_tracer; +} + +#ifdef CONFIG_FTRACE_SELFTEST +/* Let selftest have access to static functions in this file */ +#include "trace_selftest.c" +#endif + +static __init void tracer_init_debugfs(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + + d_tracer = tracing_init_dentry(); + + entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, + &global_trace, &tracing_ctrl_fops); + if (!entry) + pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); + + entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, + NULL, &tracing_iter_fops); + if (!entry) + pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); + + entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer, + NULL, &tracing_cpumask_fops); + if (!entry) + pr_warning("Could not create debugfs 'tracing_cpumask' entry\n"); + + entry = debugfs_create_file("latency_trace", 0444, d_tracer, + &global_trace, &tracing_lt_fops); + if (!entry) + pr_warning("Could not create debugfs 'latency_trace' entry\n"); + + entry = debugfs_create_file("trace", 0444, d_tracer, + &global_trace, &tracing_fops); + if (!entry) + pr_warning("Could not create debugfs 'trace' entry\n"); + + entry = debugfs_create_file("available_tracers", 0444, d_tracer, + &global_trace, &show_traces_fops); + if (!entry) + pr_warning("Could not create debugfs 'trace' entry\n"); + + entry = debugfs_create_file("current_tracer", 0444, d_tracer, + &global_trace, &set_tracer_fops); + if (!entry) + pr_warning("Could not create debugfs 'trace' entry\n"); + + entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, + &tracing_max_latency, + &tracing_max_lat_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'tracing_max_latency' entry\n"); + + entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, + &tracing_thresh, &tracing_max_lat_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'tracing_threash' entry\n"); + entry = debugfs_create_file("README", 0644, d_tracer, + NULL, &tracing_readme_fops); + if (!entry) + pr_warning("Could not create debugfs 'README' entry\n"); + + entry = debugfs_create_file("trace_pipe", 0644, d_tracer, + NULL, &tracing_pipe_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'tracing_threash' entry\n"); + + entry = debugfs_create_file("trace_entries", 0644, d_tracer, + &global_trace, &tracing_entries_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'tracing_threash' entry\n"); + +#ifdef CONFIG_DYNAMIC_FTRACE + entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, + &ftrace_update_tot_cnt, + &tracing_read_long_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'dyn_ftrace_total_info' entry\n"); +#endif +#ifdef CONFIG_SYSPROF_TRACER + init_tracer_sysprof_debugfs(d_tracer); +#endif +} + +static int trace_alloc_page(void) +{ + struct trace_array_cpu *data; + struct page *page, *tmp; + LIST_HEAD(pages); + void *array; + unsigned pages_allocated = 0; + int i; + + /* first allocate a page for each CPU */ + for_each_tracing_cpu(i) { + array = (void *)__get_free_page(GFP_KERNEL); + if (array == NULL) { + printk(KERN_ERR "tracer: failed to allocate page" + "for trace buffer!\n"); + goto free_pages; + } + + pages_allocated++; + page = virt_to_page(array); + list_add(&page->lru, &pages); + +/* Only allocate if we are actually using the max trace */ +#ifdef CONFIG_TRACER_MAX_TRACE + array = (void *)__get_free_page(GFP_KERNEL); + if (array == NULL) { + printk(KERN_ERR "tracer: failed to allocate page" + "for trace buffer!\n"); + goto free_pages; + } + pages_allocated++; + page = virt_to_page(array); + list_add(&page->lru, &pages); +#endif + } + + /* Now that we successfully allocate a page per CPU, add them */ + for_each_tracing_cpu(i) { + data = global_trace.data[i]; + page = list_entry(pages.next, struct page, lru); + list_del_init(&page->lru); + list_add_tail(&page->lru, &data->trace_pages); + ClearPageLRU(page); + +#ifdef CONFIG_TRACER_MAX_TRACE + data = max_tr.data[i]; + page = list_entry(pages.next, struct page, lru); + list_del_init(&page->lru); + list_add_tail(&page->lru, &data->trace_pages); + SetPageLRU(page); +#endif + } + tracing_pages_allocated += pages_allocated; + global_trace.entries += ENTRIES_PER_PAGE; + + return 0; + + free_pages: + list_for_each_entry_safe(page, tmp, &pages, lru) { + list_del_init(&page->lru); + __free_page(page); + } + return -ENOMEM; +} + +static int trace_free_page(void) +{ + struct trace_array_cpu *data; + struct page *page; + struct list_head *p; + int i; + int ret = 0; + + /* free one page from each buffer */ + for_each_tracing_cpu(i) { + data = global_trace.data[i]; + p = data->trace_pages.next; + if (p == &data->trace_pages) { + /* should never happen */ + WARN_ON(1); + tracing_disabled = 1; + ret = -1; + break; + } + page = list_entry(p, struct page, lru); + ClearPageLRU(page); + list_del(&page->lru); + tracing_pages_allocated--; + tracing_pages_allocated--; + __free_page(page); + + tracing_reset(data); + +#ifdef CONFIG_TRACER_MAX_TRACE + data = max_tr.data[i]; + p = data->trace_pages.next; + if (p == &data->trace_pages) { + /* should never happen */ + WARN_ON(1); + tracing_disabled = 1; + ret = -1; + break; + } + page = list_entry(p, struct page, lru); + ClearPageLRU(page); + list_del(&page->lru); + __free_page(page); + + tracing_reset(data); +#endif + } + global_trace.entries -= ENTRIES_PER_PAGE; + + return ret; +} + +__init static int tracer_alloc_buffers(void) +{ + struct trace_array_cpu *data; + void *array; + struct page *page; + int pages = 0; + int ret = -ENOMEM; + int i; + + /* TODO: make the number of buffers hot pluggable with CPUS */ + tracing_nr_buffers = num_possible_cpus(); + tracing_buffer_mask = cpu_possible_map; + + /* Allocate the first page for all buffers */ + for_each_tracing_cpu(i) { + data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); + max_tr.data[i] = &per_cpu(max_data, i); + + array = (void *)__get_free_page(GFP_KERNEL); + if (array == NULL) { + printk(KERN_ERR "tracer: failed to allocate page" + "for trace buffer!\n"); + goto free_buffers; + } + + /* set the array to the list */ + INIT_LIST_HEAD(&data->trace_pages); + page = virt_to_page(array); + list_add(&page->lru, &data->trace_pages); + /* use the LRU flag to differentiate the two buffers */ + ClearPageLRU(page); + + data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + +/* Only allocate if we are actually using the max trace */ +#ifdef CONFIG_TRACER_MAX_TRACE + array = (void *)__get_free_page(GFP_KERNEL); + if (array == NULL) { + printk(KERN_ERR "tracer: failed to allocate page" + "for trace buffer!\n"); + goto free_buffers; + } + + INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); + page = virt_to_page(array); + list_add(&page->lru, &max_tr.data[i]->trace_pages); + SetPageLRU(page); +#endif + } + + /* + * Since we allocate by orders of pages, we may be able to + * round up a bit. + */ + global_trace.entries = ENTRIES_PER_PAGE; + pages++; + + while (global_trace.entries < trace_nr_entries) { + if (trace_alloc_page()) + break; + pages++; + } + max_tr.entries = global_trace.entries; + + pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n", + pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE); + pr_info(" actual entries %ld\n", global_trace.entries); + + tracer_init_debugfs(); + + trace_init_cmdlines(); + + register_tracer(&no_tracer); + current_trace = &no_tracer; + + /* All seems OK, enable tracing */ + global_trace.ctrl = tracer_enabled; + tracing_disabled = 0; + + return 0; + + free_buffers: + for (i-- ; i >= 0; i--) { + struct page *page, *tmp; + struct trace_array_cpu *data = global_trace.data[i]; + + if (data) { + list_for_each_entry_safe(page, tmp, + &data->trace_pages, lru) { + list_del_init(&page->lru); + __free_page(page); + } + } + +#ifdef CONFIG_TRACER_MAX_TRACE + data = max_tr.data[i]; + if (data) { + list_for_each_entry_safe(page, tmp, + &data->trace_pages, lru) { + list_del_init(&page->lru); + __free_page(page); + } + } +#endif + } + return ret; +} +fs_initcall(tracer_alloc_buffers); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h new file mode 100644 index 0000000..f69f867 --- /dev/null +++ b/kernel/trace/trace.h @@ -0,0 +1,339 @@ +#ifndef _LINUX_KERNEL_TRACE_H +#define _LINUX_KERNEL_TRACE_H + +#include <linux/fs.h> +#include <asm/atomic.h> +#include <linux/sched.h> +#include <linux/clocksource.h> +#include <linux/mmiotrace.h> + +enum trace_type { + __TRACE_FIRST_TYPE = 0, + + TRACE_FN, + TRACE_CTX, + TRACE_WAKE, + TRACE_STACK, + TRACE_SPECIAL, + TRACE_MMIO_RW, + TRACE_MMIO_MAP, + + __TRACE_LAST_TYPE +}; + +/* + * Function trace entry - function address and parent function addres: + */ +struct ftrace_entry { + unsigned long ip; + unsigned long parent_ip; +}; + +/* + * Context switch trace entry - which task (and prio) we switched from/to: + */ +struct ctx_switch_entry { + unsigned int prev_pid; + unsigned char prev_prio; + unsigned char prev_state; + unsigned int next_pid; + unsigned char next_prio; + unsigned char next_state; +}; + +/* + * Special (free-form) trace entry: + */ +struct special_entry { + unsigned long arg1; + unsigned long arg2; + unsigned long arg3; +}; + +/* + * Stack-trace entry: + */ + +#define FTRACE_STACK_ENTRIES 8 + +struct stack_entry { + unsigned long caller[FTRACE_STACK_ENTRIES]; +}; + +/* + * The trace entry - the most basic unit of tracing. This is what + * is printed in the end as a single line in the trace output, such as: + * + * bash-15816 [01] 235.197585: idle_cpu <- irq_enter + */ +struct trace_entry { + char type; + char cpu; + char flags; + char preempt_count; + int pid; + cycle_t t; + union { + struct ftrace_entry fn; + struct ctx_switch_entry ctx; + struct special_entry special; + struct stack_entry stack; + struct mmiotrace_rw mmiorw; + struct mmiotrace_map mmiomap; + }; +}; + +#define TRACE_ENTRY_SIZE sizeof(struct trace_entry) + +/* + * The CPU trace array - it consists of thousands of trace entries + * plus some other descriptor data: (for example which task started + * the trace, etc.) + */ +struct trace_array_cpu { + struct list_head trace_pages; + atomic_t disabled; + raw_spinlock_t lock; + struct lock_class_key lock_key; + + /* these fields get copied into max-trace: */ + unsigned trace_head_idx; + unsigned trace_tail_idx; + void *trace_head; /* producer */ + void *trace_tail; /* consumer */ + unsigned long trace_idx; + unsigned long overrun; + unsigned long saved_latency; + unsigned long critical_start; + unsigned long critical_end; + unsigned long critical_sequence; + unsigned long nice; + unsigned long policy; + unsigned long rt_priority; + cycle_t preempt_timestamp; + pid_t pid; + uid_t uid; + char comm[TASK_COMM_LEN]; +}; + +struct trace_iterator; + +/* + * The trace array - an array of per-CPU trace arrays. This is the + * highest level data structure that individual tracers deal with. + * They have on/off state as well: + */ +struct trace_array { + unsigned long entries; + long ctrl; + int cpu; + cycle_t time_start; + struct task_struct *waiter; + struct trace_array_cpu *data[NR_CPUS]; +}; + +/* + * A specific tracer, represented by methods that operate on a trace array: + */ +struct tracer { + const char *name; + void (*init)(struct trace_array *tr); + void (*reset)(struct trace_array *tr); + void (*open)(struct trace_iterator *iter); + void (*pipe_open)(struct trace_iterator *iter); + void (*close)(struct trace_iterator *iter); + void (*start)(struct trace_iterator *iter); + void (*stop)(struct trace_iterator *iter); + ssize_t (*read)(struct trace_iterator *iter, + struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos); + void (*ctrl_update)(struct trace_array *tr); +#ifdef CONFIG_FTRACE_STARTUP_TEST + int (*selftest)(struct tracer *trace, + struct trace_array *tr); +#endif + int (*print_line)(struct trace_iterator *iter); + struct tracer *next; + int print_max; +}; + +struct trace_seq { + unsigned char buffer[PAGE_SIZE]; + unsigned int len; + unsigned int readpos; +}; + +/* + * Trace iterator - used by printout routines who present trace + * results to users and which routines might sleep, etc: + */ +struct trace_iterator { + struct trace_array *tr; + struct tracer *trace; + void *private; + long last_overrun[NR_CPUS]; + long overrun[NR_CPUS]; + + /* The below is zeroed out in pipe_read */ + struct trace_seq seq; + struct trace_entry *ent; + int cpu; + + struct trace_entry *prev_ent; + int prev_cpu; + + unsigned long iter_flags; + loff_t pos; + unsigned long next_idx[NR_CPUS]; + struct list_head *next_page[NR_CPUS]; + unsigned next_page_idx[NR_CPUS]; + long idx; +}; + +void tracing_reset(struct trace_array_cpu *data); +int tracing_open_generic(struct inode *inode, struct file *filp); +struct dentry *tracing_init_dentry(void); +void init_tracer_sysprof_debugfs(struct dentry *d_tracer); + +void ftrace(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long ip, + unsigned long parent_ip, + unsigned long flags); +void tracing_sched_switch_trace(struct trace_array *tr, + struct trace_array_cpu *data, + struct task_struct *prev, + struct task_struct *next, + unsigned long flags); +void tracing_record_cmdline(struct task_struct *tsk); + +void tracing_sched_wakeup_trace(struct trace_array *tr, + struct trace_array_cpu *data, + struct task_struct *wakee, + struct task_struct *cur, + unsigned long flags); +void trace_special(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long arg1, + unsigned long arg2, + unsigned long arg3); +void trace_function(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long ip, + unsigned long parent_ip, + unsigned long flags); + +void tracing_start_cmdline_record(void); +void tracing_stop_cmdline_record(void); +int register_tracer(struct tracer *type); +void unregister_tracer(struct tracer *type); + +extern unsigned long nsecs_to_usecs(unsigned long nsecs); + +extern unsigned long tracing_max_latency; +extern unsigned long tracing_thresh; + +void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); +void update_max_tr_single(struct trace_array *tr, + struct task_struct *tsk, int cpu); + +extern cycle_t ftrace_now(int cpu); + +#ifdef CONFIG_FTRACE +void tracing_start_function_trace(void); +void tracing_stop_function_trace(void); +#else +# define tracing_start_function_trace() do { } while (0) +# define tracing_stop_function_trace() do { } while (0) +#endif + +#ifdef CONFIG_CONTEXT_SWITCH_TRACER +typedef void +(*tracer_switch_func_t)(void *private, + void *__rq, + struct task_struct *prev, + struct task_struct *next); + +struct tracer_switch_ops { + tracer_switch_func_t func; + void *private; + struct tracer_switch_ops *next; +}; + +#endif /* CONFIG_CONTEXT_SWITCH_TRACER */ + +#ifdef CONFIG_DYNAMIC_FTRACE +extern unsigned long ftrace_update_tot_cnt; +#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func +extern int DYN_FTRACE_TEST_NAME(void); +#endif + +#ifdef CONFIG_MMIOTRACE +extern void __trace_mmiotrace_rw(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_rw *rw); +extern void __trace_mmiotrace_map(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_map *map); +#endif + +#ifdef CONFIG_FTRACE_STARTUP_TEST +#ifdef CONFIG_FTRACE +extern int trace_selftest_startup_function(struct tracer *trace, + struct trace_array *tr); +#endif +#ifdef CONFIG_IRQSOFF_TRACER +extern int trace_selftest_startup_irqsoff(struct tracer *trace, + struct trace_array *tr); +#endif +#ifdef CONFIG_PREEMPT_TRACER +extern int trace_selftest_startup_preemptoff(struct tracer *trace, + struct trace_array *tr); +#endif +#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) +extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, + struct trace_array *tr); +#endif +#ifdef CONFIG_SCHED_TRACER +extern int trace_selftest_startup_wakeup(struct tracer *trace, + struct trace_array *tr); +#endif +#ifdef CONFIG_CONTEXT_SWITCH_TRACER +extern int trace_selftest_startup_sched_switch(struct tracer *trace, + struct trace_array *tr); +#endif +#ifdef CONFIG_SYSPROF_TRACER +extern int trace_selftest_startup_sysprof(struct tracer *trace, + struct trace_array *tr); +#endif +#endif /* CONFIG_FTRACE_STARTUP_TEST */ + +extern void *head_page(struct trace_array_cpu *data); +extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); +extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, + size_t cnt); +extern long ns2usecs(cycle_t nsec); + +extern unsigned long trace_flags; + +/* + * trace_iterator_flags is an enumeration that defines bit + * positions into trace_flags that controls the output. + * + * NOTE: These bits must match the trace_options array in + * trace.c. + */ +enum trace_iterator_flags { + TRACE_ITER_PRINT_PARENT = 0x01, + TRACE_ITER_SYM_OFFSET = 0x02, + TRACE_ITER_SYM_ADDR = 0x04, + TRACE_ITER_VERBOSE = 0x08, + TRACE_ITER_RAW = 0x10, + TRACE_ITER_HEX = 0x20, + TRACE_ITER_BIN = 0x40, + TRACE_ITER_BLOCK = 0x80, + TRACE_ITER_STACKTRACE = 0x100, + TRACE_ITER_SCHED_TREE = 0x200, +}; + +#endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c new file mode 100644 index 0000000..3121448 --- /dev/null +++ b/kernel/trace/trace_functions.c @@ -0,0 +1,81 @@ +/* + * ring buffer based function tracer + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + * + * Based on code from the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/fs.h> + +#include "trace.h" + +static void function_reset(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); +} + +static void start_function_trace(struct trace_array *tr) +{ + tr->cpu = get_cpu(); + function_reset(tr); + put_cpu(); + + tracing_start_cmdline_record(); + tracing_start_function_trace(); +} + +static void stop_function_trace(struct trace_array *tr) +{ + tracing_stop_function_trace(); + tracing_stop_cmdline_record(); +} + +static void function_trace_init(struct trace_array *tr) +{ + if (tr->ctrl) + start_function_trace(tr); +} + +static void function_trace_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_function_trace(tr); +} + +static void function_trace_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_function_trace(tr); + else + stop_function_trace(tr); +} + +static struct tracer function_trace __read_mostly = +{ + .name = "ftrace", + .init = function_trace_init, + .reset = function_trace_reset, + .ctrl_update = function_trace_ctrl_update, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_function, +#endif +}; + +static __init int init_function_trace(void) +{ + return register_tracer(&function_trace); +} + +device_initcall(init_function_trace); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c new file mode 100644 index 0000000..ece6cfb --- /dev/null +++ b/kernel/trace/trace_irqsoff.c @@ -0,0 +1,490 @@ +/* + * trace irqs off criticall timings + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + * + * From code in the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ +#include <linux/kallsyms.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/ftrace.h> +#include <linux/fs.h> + +#include "trace.h" + +static struct trace_array *irqsoff_trace __read_mostly; +static int tracer_enabled __read_mostly; + +static DEFINE_PER_CPU(int, tracing_cpu); + +static DEFINE_SPINLOCK(max_trace_lock); + +enum { + TRACER_IRQS_OFF = (1 << 1), + TRACER_PREEMPT_OFF = (1 << 2), +}; + +static int trace_type __read_mostly; + +#ifdef CONFIG_PREEMPT_TRACER +static inline int +preempt_trace(void) +{ + return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count()); +} +#else +# define preempt_trace() (0) +#endif + +#ifdef CONFIG_IRQSOFF_TRACER +static inline int +irq_trace(void) +{ + return ((trace_type & TRACER_IRQS_OFF) && + irqs_disabled()); +} +#else +# define irq_trace() (0) +#endif + +/* + * Sequence count - we record it when starting a measurement and + * skip the latency if the sequence has changed - some other section + * did a maximum and could disturb our measurement with serial console + * printouts, etc. Truly coinciding maximum latencies should be rare + * and what happens together happens separately as well, so this doesnt + * decrease the validity of the maximum found: + */ +static __cacheline_aligned_in_smp unsigned long max_sequence; + +#ifdef CONFIG_FTRACE +/* + * irqsoff uses its own tracer function to keep the overhead down: + */ +static void +irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + /* + * Does not matter if we preempt. We test the flags + * afterward, to see if irqs are disabled or not. + * If we preempt and get a false positive, the flags + * test will fail. + */ + cpu = raw_smp_processor_id(); + if (likely(!per_cpu(tracing_cpu, cpu))) + return; + + local_save_flags(flags); + /* slight chance to get a false positive on tracing_cpu */ + if (!irqs_disabled_flags(flags)) + return; + + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + trace_function(tr, data, ip, parent_ip, flags); + + atomic_dec(&data->disabled); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = irqsoff_tracer_call, +}; +#endif /* CONFIG_FTRACE */ + +/* + * Should this new latency be reported/recorded? + */ +static int report_latency(cycle_t delta) +{ + if (tracing_thresh) { + if (delta < tracing_thresh) + return 0; + } else { + if (delta <= tracing_max_latency) + return 0; + } + return 1; +} + +static void +check_critical_timing(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long parent_ip, + int cpu) +{ + unsigned long latency, t0, t1; + cycle_t T0, T1, delta; + unsigned long flags; + + /* + * usecs conversion is slow so we try to delay the conversion + * as long as possible: + */ + T0 = data->preempt_timestamp; + T1 = ftrace_now(cpu); + delta = T1-T0; + + local_save_flags(flags); + + if (!report_latency(delta)) + goto out; + + spin_lock_irqsave(&max_trace_lock, flags); + + /* check if we are still the max latency */ + if (!report_latency(delta)) + goto out_unlock; + + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); + + latency = nsecs_to_usecs(delta); + + if (data->critical_sequence != max_sequence) + goto out_unlock; + + tracing_max_latency = delta; + t0 = nsecs_to_usecs(T0); + t1 = nsecs_to_usecs(T1); + + data->critical_end = parent_ip; + + update_max_tr_single(tr, current, cpu); + + max_sequence++; + +out_unlock: + spin_unlock_irqrestore(&max_trace_lock, flags); + +out: + data->critical_sequence = max_sequence; + data->preempt_timestamp = ftrace_now(cpu); + tracing_reset(data); + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); +} + +static inline void +start_critical_timing(unsigned long ip, unsigned long parent_ip) +{ + int cpu; + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + + if (likely(!tracer_enabled)) + return; + + cpu = raw_smp_processor_id(); + + if (per_cpu(tracing_cpu, cpu)) + return; + + data = tr->data[cpu]; + + if (unlikely(!data) || atomic_read(&data->disabled)) + return; + + atomic_inc(&data->disabled); + + data->critical_sequence = max_sequence; + data->preempt_timestamp = ftrace_now(cpu); + data->critical_start = parent_ip ? : ip; + tracing_reset(data); + + local_save_flags(flags); + + trace_function(tr, data, ip, parent_ip, flags); + + per_cpu(tracing_cpu, cpu) = 1; + + atomic_dec(&data->disabled); +} + +static inline void +stop_critical_timing(unsigned long ip, unsigned long parent_ip) +{ + int cpu; + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + + cpu = raw_smp_processor_id(); + /* Always clear the tracing cpu on stopping the trace */ + if (unlikely(per_cpu(tracing_cpu, cpu))) + per_cpu(tracing_cpu, cpu) = 0; + else + return; + + if (!tracer_enabled) + return; + + data = tr->data[cpu]; + + if (unlikely(!data) || unlikely(!head_page(data)) || + !data->critical_start || atomic_read(&data->disabled)) + return; + + atomic_inc(&data->disabled); + + local_save_flags(flags); + trace_function(tr, data, ip, parent_ip, flags); + check_critical_timing(tr, data, parent_ip ? : ip, cpu); + data->critical_start = 0; + atomic_dec(&data->disabled); +} + +/* start and stop critical timings used to for stoppage (in idle) */ +void start_critical_timings(void) +{ + if (preempt_trace() || irq_trace()) + start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL_GPL(start_critical_timings); + +void stop_critical_timings(void) +{ + if (preempt_trace() || irq_trace()) + stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL_GPL(stop_critical_timings); + +#ifdef CONFIG_IRQSOFF_TRACER +#ifdef CONFIG_PROVE_LOCKING +void time_hardirqs_on(unsigned long a0, unsigned long a1) +{ + if (!preempt_trace() && irq_trace()) + stop_critical_timing(a0, a1); +} + +void time_hardirqs_off(unsigned long a0, unsigned long a1) +{ + if (!preempt_trace() && irq_trace()) + start_critical_timing(a0, a1); +} + +#else /* !CONFIG_PROVE_LOCKING */ + +/* + * Stubs: + */ + +void early_boot_irqs_off(void) +{ +} + +void early_boot_irqs_on(void) +{ +} + +void trace_softirqs_on(unsigned long ip) +{ +} + +void trace_softirqs_off(unsigned long ip) +{ +} + +inline void print_irqtrace_events(struct task_struct *curr) +{ +} + +/* + * We are only interested in hardirq on/off events: + */ +void trace_hardirqs_on(void) +{ + if (!preempt_trace() && irq_trace()) + stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL(trace_hardirqs_on); + +void trace_hardirqs_off(void) +{ + if (!preempt_trace() && irq_trace()) + start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL(trace_hardirqs_off); + +void trace_hardirqs_on_caller(unsigned long caller_addr) +{ + if (!preempt_trace() && irq_trace()) + stop_critical_timing(CALLER_ADDR0, caller_addr); +} +EXPORT_SYMBOL(trace_hardirqs_on_caller); + +void trace_hardirqs_off_caller(unsigned long caller_addr) +{ + if (!preempt_trace() && irq_trace()) + start_critical_timing(CALLER_ADDR0, caller_addr); +} +EXPORT_SYMBOL(trace_hardirqs_off_caller); + +#endif /* CONFIG_PROVE_LOCKING */ +#endif /* CONFIG_IRQSOFF_TRACER */ + +#ifdef CONFIG_PREEMPT_TRACER +void trace_preempt_on(unsigned long a0, unsigned long a1) +{ + if (preempt_trace()) + stop_critical_timing(a0, a1); +} + +void trace_preempt_off(unsigned long a0, unsigned long a1) +{ + if (preempt_trace()) + start_critical_timing(a0, a1); +} +#endif /* CONFIG_PREEMPT_TRACER */ + +static void start_irqsoff_tracer(struct trace_array *tr) +{ + register_ftrace_function(&trace_ops); + tracer_enabled = 1; +} + +static void stop_irqsoff_tracer(struct trace_array *tr) +{ + tracer_enabled = 0; + unregister_ftrace_function(&trace_ops); +} + +static void __irqsoff_tracer_init(struct trace_array *tr) +{ + irqsoff_trace = tr; + /* make sure that the tracer is visible */ + smp_wmb(); + + if (tr->ctrl) + start_irqsoff_tracer(tr); +} + +static void irqsoff_tracer_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_irqsoff_tracer(tr); +} + +static void irqsoff_tracer_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_irqsoff_tracer(tr); + else + stop_irqsoff_tracer(tr); +} + +static void irqsoff_tracer_open(struct trace_iterator *iter) +{ + /* stop the trace while dumping */ + if (iter->tr->ctrl) + stop_irqsoff_tracer(iter->tr); +} + +static void irqsoff_tracer_close(struct trace_iterator *iter) +{ + if (iter->tr->ctrl) + start_irqsoff_tracer(iter->tr); +} + +#ifdef CONFIG_IRQSOFF_TRACER +static void irqsoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_IRQS_OFF; + + __irqsoff_tracer_init(tr); +} +static struct tracer irqsoff_tracer __read_mostly = +{ + .name = "irqsoff", + .init = irqsoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_irqsoff, +#endif +}; +# define register_irqsoff(trace) register_tracer(&trace) +#else +# define register_irqsoff(trace) do { } while (0) +#endif + +#ifdef CONFIG_PREEMPT_TRACER +static void preemptoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_PREEMPT_OFF; + + __irqsoff_tracer_init(tr); +} + +static struct tracer preemptoff_tracer __read_mostly = +{ + .name = "preemptoff", + .init = preemptoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_preemptoff, +#endif +}; +# define register_preemptoff(trace) register_tracer(&trace) +#else +# define register_preemptoff(trace) do { } while (0) +#endif + +#if defined(CONFIG_IRQSOFF_TRACER) && \ + defined(CONFIG_PREEMPT_TRACER) + +static void preemptirqsoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; + + __irqsoff_tracer_init(tr); +} + +static struct tracer preemptirqsoff_tracer __read_mostly = +{ + .name = "preemptirqsoff", + .init = preemptirqsoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_preemptirqsoff, +#endif +}; + +# define register_preemptirqsoff(trace) register_tracer(&trace) +#else +# define register_preemptirqsoff(trace) do { } while (0) +#endif + +__init static int init_irqsoff_tracer(void) +{ + register_irqsoff(irqsoff_tracer); + register_preemptoff(preemptoff_tracer); + register_preemptirqsoff(preemptirqsoff_tracer); + + return 0; +} +device_initcall(init_irqsoff_tracer); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c new file mode 100644 index 0000000..b13dc19 --- /dev/null +++ b/kernel/trace/trace_mmiotrace.c @@ -0,0 +1,295 @@ +/* + * Memory mapped I/O tracing + * + * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi> + */ + +#define DEBUG 1 + +#include <linux/kernel.h> +#include <linux/mmiotrace.h> +#include <linux/pci.h> + +#include "trace.h" + +struct header_iter { + struct pci_dev *dev; +}; + +static struct trace_array *mmio_trace_array; +static bool overrun_detected; + +static void mmio_reset_data(struct trace_array *tr) +{ + int cpu; + + overrun_detected = false; + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); +} + +static void mmio_trace_init(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + mmio_trace_array = tr; + if (tr->ctrl) { + mmio_reset_data(tr); + enable_mmiotrace(); + } +} + +static void mmio_trace_reset(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + if (tr->ctrl) + disable_mmiotrace(); + mmio_reset_data(tr); + mmio_trace_array = NULL; +} + +static void mmio_trace_ctrl_update(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + if (tr->ctrl) { + mmio_reset_data(tr); + enable_mmiotrace(); + } else { + disable_mmiotrace(); + } +} + +static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) +{ + int ret = 0; + int i; + resource_size_t start, end; + const struct pci_driver *drv = pci_dev_driver(dev); + + /* XXX: incomplete checks for trace_seq_printf() return value */ + ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", + dev->bus->number, dev->devfn, + dev->vendor, dev->device, dev->irq); + /* + * XXX: is pci_resource_to_user() appropriate, since we are + * supposed to interpret the __ioremap() phys_addr argument based on + * these printed values? + */ + for (i = 0; i < 7; i++) { + pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + ret += trace_seq_printf(s, " %llx", + (unsigned long long)(start | + (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); + } + for (i = 0; i < 7; i++) { + pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + ret += trace_seq_printf(s, " %llx", + dev->resource[i].start < dev->resource[i].end ? + (unsigned long long)(end - start) + 1 : 0); + } + if (drv) + ret += trace_seq_printf(s, " %s\n", drv->name); + else + ret += trace_seq_printf(s, " \n"); + return ret; +} + +static void destroy_header_iter(struct header_iter *hiter) +{ + if (!hiter) + return; + pci_dev_put(hiter->dev); + kfree(hiter); +} + +static void mmio_pipe_open(struct trace_iterator *iter) +{ + struct header_iter *hiter; + struct trace_seq *s = &iter->seq; + + trace_seq_printf(s, "VERSION 20070824\n"); + + hiter = kzalloc(sizeof(*hiter), GFP_KERNEL); + if (!hiter) + return; + + hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); + iter->private = hiter; +} + +/* XXX: This is not called when the pipe is closed! */ +static void mmio_close(struct trace_iterator *iter) +{ + struct header_iter *hiter = iter->private; + destroy_header_iter(hiter); + iter->private = NULL; +} + +static unsigned long count_overruns(struct trace_iterator *iter) +{ + int cpu; + unsigned long cnt = 0; + for_each_online_cpu(cpu) { + cnt += iter->overrun[cpu]; + iter->overrun[cpu] = 0; + } + return cnt; +} + +static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp, + char __user *ubuf, size_t cnt, loff_t *ppos) +{ + ssize_t ret; + struct header_iter *hiter = iter->private; + struct trace_seq *s = &iter->seq; + unsigned long n; + + n = count_overruns(iter); + if (n) { + /* XXX: This is later than where events were lost. */ + trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n); + if (!overrun_detected) + pr_warning("mmiotrace has lost events.\n"); + overrun_detected = true; + goto print_out; + } + + if (!hiter) + return 0; + + mmio_print_pcidev(s, hiter->dev); + hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev); + + if (!hiter->dev) { + destroy_header_iter(hiter); + iter->private = NULL; + } + +print_out: + ret = trace_seq_to_user(s, ubuf, cnt); + return (ret == -EBUSY) ? 0 : ret; +} + +static int mmio_print_rw(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct mmiotrace_rw *rw = &entry->mmiorw; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(entry->t); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret = 1; + + switch (entry->mmiorw.opcode) { + case MMIO_READ: + ret = trace_seq_printf(s, + "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, + rw->value, rw->pc, 0); + break; + case MMIO_WRITE: + ret = trace_seq_printf(s, + "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, + rw->value, rw->pc, 0); + break; + case MMIO_UNKNOWN_OP: + ret = trace_seq_printf(s, + "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n", + secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, + (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff, + (rw->value >> 0) & 0xff, rw->pc, 0); + break; + default: + ret = trace_seq_printf(s, "rw what?\n"); + break; + } + if (ret) + return 1; + return 0; +} + +static int mmio_print_map(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct mmiotrace_map *m = &entry->mmiomap; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(entry->t); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret = 1; + + switch (entry->mmiorw.opcode) { + case MMIO_PROBE: + ret = trace_seq_printf(s, + "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", + secs, usec_rem, m->map_id, + (unsigned long long)m->phys, m->virt, m->len, + 0UL, 0); + break; + case MMIO_UNPROBE: + ret = trace_seq_printf(s, + "UNMAP %lu.%06lu %d 0x%lx %d\n", + secs, usec_rem, m->map_id, 0UL, 0); + break; + default: + ret = trace_seq_printf(s, "map what?\n"); + break; + } + if (ret) + return 1; + return 0; +} + +/* return 0 to abort printing without consuming current entry in pipe mode */ +static int mmio_print_line(struct trace_iterator *iter) +{ + switch (iter->ent->type) { + case TRACE_MMIO_RW: + return mmio_print_rw(iter); + case TRACE_MMIO_MAP: + return mmio_print_map(iter); + default: + return 1; /* ignore unknown entries */ + } +} + +static struct tracer mmio_tracer __read_mostly = +{ + .name = "mmiotrace", + .init = mmio_trace_init, + .reset = mmio_trace_reset, + .pipe_open = mmio_pipe_open, + .close = mmio_close, + .read = mmio_read, + .ctrl_update = mmio_trace_ctrl_update, + .print_line = mmio_print_line, +}; + +__init static int init_mmio_trace(void) +{ + return register_tracer(&mmio_tracer); +} +device_initcall(init_mmio_trace); + +void mmio_trace_rw(struct mmiotrace_rw *rw) +{ + struct trace_array *tr = mmio_trace_array; + struct trace_array_cpu *data = tr->data[smp_processor_id()]; + __trace_mmiotrace_rw(tr, data, rw); +} + +void mmio_trace_mapping(struct mmiotrace_map *map) +{ + struct trace_array *tr = mmio_trace_array; + struct trace_array_cpu *data; + + preempt_disable(); + data = tr->data[smp_processor_id()]; + __trace_mmiotrace_map(tr, data, map); + preempt_enable(); +} diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c new file mode 100644 index 0000000..cb817a2 --- /dev/null +++ b/kernel/trace/trace_sched_switch.c @@ -0,0 +1,286 @@ +/* + * trace context switch + * + * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com> + * + */ +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/debugfs.h> +#include <linux/kallsyms.h> +#include <linux/uaccess.h> +#include <linux/marker.h> +#include <linux/ftrace.h> + +#include "trace.h" + +static struct trace_array *ctx_trace; +static int __read_mostly tracer_enabled; +static atomic_t sched_ref; + +static void +sched_switch_func(void *private, void *__rq, struct task_struct *prev, + struct task_struct *next) +{ + struct trace_array **ptr = private; + struct trace_array *tr = *ptr; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + tracing_record_cmdline(prev); + tracing_record_cmdline(next); + + if (!tracer_enabled) + return; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + tracing_sched_switch_trace(tr, data, prev, next, flags); + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static notrace void +sched_switch_callback(void *probe_data, void *call_data, + const char *format, va_list *args) +{ + struct task_struct *prev; + struct task_struct *next; + struct rq *__rq; + + if (!atomic_read(&sched_ref)) + return; + + /* skip prev_pid %d next_pid %d prev_state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, int); + (void)va_arg(*args, long); + __rq = va_arg(*args, typeof(__rq)); + prev = va_arg(*args, typeof(prev)); + next = va_arg(*args, typeof(next)); + + /* + * If tracer_switch_func only points to the local + * switch func, it still needs the ptr passed to it. + */ + sched_switch_func(probe_data, __rq, prev, next); +} + +static void +wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct + task_struct *curr) +{ + struct trace_array **ptr = private; + struct trace_array *tr = *ptr; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + if (!tracer_enabled) + return; + + tracing_record_cmdline(curr); + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + tracing_sched_wakeup_trace(tr, data, wakee, curr, flags); + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static notrace void +wake_up_callback(void *probe_data, void *call_data, + const char *format, va_list *args) +{ + struct task_struct *curr; + struct task_struct *task; + struct rq *__rq; + + if (likely(!tracer_enabled)) + return; + + /* Skip pid %d state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, long); + /* now get the meat: "rq %p task %p rq->curr %p" */ + __rq = va_arg(*args, typeof(__rq)); + task = va_arg(*args, typeof(task)); + curr = va_arg(*args, typeof(curr)); + + tracing_record_cmdline(task); + tracing_record_cmdline(curr); + + wakeup_func(probe_data, __rq, task, curr); +} + +static void sched_switch_reset(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); +} + +static int tracing_sched_register(void) +{ + int ret; + + ret = marker_probe_register("kernel_sched_wakeup", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &ctx_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup\n"); + return ret; + } + + ret = marker_probe_register("kernel_sched_wakeup_new", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &ctx_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup_new\n"); + goto fail_deprobe; + } + + ret = marker_probe_register("kernel_sched_schedule", + "prev_pid %d next_pid %d prev_state %ld " + "## rq %p prev %p next %p", + sched_switch_callback, + &ctx_trace); + if (ret) { + pr_info("sched trace: Couldn't add marker" + " probe to kernel_sched_schedule\n"); + goto fail_deprobe_wake_new; + } + + return ret; +fail_deprobe_wake_new: + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &ctx_trace); +fail_deprobe: + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &ctx_trace); + return ret; +} + +static void tracing_sched_unregister(void) +{ + marker_probe_unregister("kernel_sched_schedule", + sched_switch_callback, + &ctx_trace); + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &ctx_trace); + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &ctx_trace); +} + +static void tracing_start_sched_switch(void) +{ + long ref; + + ref = atomic_inc_return(&sched_ref); + if (ref == 1) + tracing_sched_register(); +} + +static void tracing_stop_sched_switch(void) +{ + long ref; + + ref = atomic_dec_and_test(&sched_ref); + if (ref) + tracing_sched_unregister(); +} + +void tracing_start_cmdline_record(void) +{ + tracing_start_sched_switch(); +} + +void tracing_stop_cmdline_record(void) +{ + tracing_stop_sched_switch(); +} + +static void start_sched_trace(struct trace_array *tr) +{ + sched_switch_reset(tr); + tracing_start_cmdline_record(); + tracer_enabled = 1; +} + +static void stop_sched_trace(struct trace_array *tr) +{ + tracer_enabled = 0; + tracing_stop_cmdline_record(); +} + +static void sched_switch_trace_init(struct trace_array *tr) +{ + ctx_trace = tr; + + if (tr->ctrl) + start_sched_trace(tr); +} + +static void sched_switch_trace_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_sched_trace(tr); +} + +static void sched_switch_trace_ctrl_update(struct trace_array *tr) +{ + /* When starting a new trace, reset the buffers */ + if (tr->ctrl) + start_sched_trace(tr); + else + stop_sched_trace(tr); +} + +static struct tracer sched_switch_trace __read_mostly = +{ + .name = "sched_switch", + .init = sched_switch_trace_init, + .reset = sched_switch_trace_reset, + .ctrl_update = sched_switch_trace_ctrl_update, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_sched_switch, +#endif +}; + +__init static int init_sched_switch_trace(void) +{ + int ret = 0; + + if (atomic_read(&sched_ref)) + ret = tracing_sched_register(); + if (ret) { + pr_info("error registering scheduler trace\n"); + return ret; + } + return register_tracer(&sched_switch_trace); +} +device_initcall(init_sched_switch_trace); diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c new file mode 100644 index 0000000..e303ccb --- /dev/null +++ b/kernel/trace/trace_sched_wakeup.c @@ -0,0 +1,453 @@ +/* + * trace task wakeup timings + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + * + * Based on code from the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/debugfs.h> +#include <linux/kallsyms.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/marker.h> + +#include "trace.h" + +static struct trace_array *wakeup_trace; +static int __read_mostly tracer_enabled; + +static struct task_struct *wakeup_task; +static int wakeup_cpu; +static unsigned wakeup_prio = -1; + +static raw_spinlock_t wakeup_lock = + (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + +static void __wakeup_reset(struct trace_array *tr); + +#ifdef CONFIG_FTRACE +/* + * irqsoff uses its own tracer function to keep the overhead down: + */ +static void +wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = wakeup_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int resched; + int cpu; + + if (likely(!wakeup_task)) + return; + + resched = need_resched(); + preempt_disable_notrace(); + + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + if (unlikely(disabled != 1)) + goto out; + + local_irq_save(flags); + __raw_spin_lock(&wakeup_lock); + + if (unlikely(!wakeup_task)) + goto unlock; + + /* + * The task can't disappear because it needs to + * wake up first, and we have the wakeup_lock. + */ + if (task_cpu(wakeup_task) != cpu) + goto unlock; + + trace_function(tr, data, ip, parent_ip, flags); + + unlock: + __raw_spin_unlock(&wakeup_lock); + local_irq_restore(flags); + + out: + atomic_dec(&data->disabled); + + /* + * To prevent recursion from the scheduler, if the + * resched flag was set before we entered, then + * don't reschedule. + */ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = wakeup_tracer_call, +}; +#endif /* CONFIG_FTRACE */ + +/* + * Should this new latency be reported/recorded? + */ +static int report_latency(cycle_t delta) +{ + if (tracing_thresh) { + if (delta < tracing_thresh) + return 0; + } else { + if (delta <= tracing_max_latency) + return 0; + } + return 1; +} + +static void notrace +wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, + struct task_struct *next) +{ + unsigned long latency = 0, t0 = 0, t1 = 0; + struct trace_array **ptr = private; + struct trace_array *tr = *ptr; + struct trace_array_cpu *data; + cycle_t T0, T1, delta; + unsigned long flags; + long disabled; + int cpu; + + if (unlikely(!tracer_enabled)) + return; + + /* + * When we start a new trace, we set wakeup_task to NULL + * and then set tracer_enabled = 1. We want to make sure + * that another CPU does not see the tracer_enabled = 1 + * and the wakeup_task with an older task, that might + * actually be the same as next. + */ + smp_rmb(); + + if (next != wakeup_task) + return; + + /* The task we are waiting for is waking up */ + data = tr->data[wakeup_cpu]; + + /* disable local data, not wakeup_cpu data */ + cpu = raw_smp_processor_id(); + disabled = atomic_inc_return(&tr->data[cpu]->disabled); + if (likely(disabled != 1)) + goto out; + + local_irq_save(flags); + __raw_spin_lock(&wakeup_lock); + + /* We could race with grabbing wakeup_lock */ + if (unlikely(!tracer_enabled || next != wakeup_task)) + goto out_unlock; + + trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags); + + /* + * usecs conversion is slow so we try to delay the conversion + * as long as possible: + */ + T0 = data->preempt_timestamp; + T1 = ftrace_now(cpu); + delta = T1-T0; + + if (!report_latency(delta)) + goto out_unlock; + + latency = nsecs_to_usecs(delta); + + tracing_max_latency = delta; + t0 = nsecs_to_usecs(T0); + t1 = nsecs_to_usecs(T1); + + update_max_tr(tr, wakeup_task, wakeup_cpu); + +out_unlock: + __wakeup_reset(tr); + __raw_spin_unlock(&wakeup_lock); + local_irq_restore(flags); +out: + atomic_dec(&tr->data[cpu]->disabled); +} + +static notrace void +sched_switch_callback(void *probe_data, void *call_data, + const char *format, va_list *args) +{ + struct task_struct *prev; + struct task_struct *next; + struct rq *__rq; + + /* skip prev_pid %d next_pid %d prev_state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, int); + (void)va_arg(*args, long); + __rq = va_arg(*args, typeof(__rq)); + prev = va_arg(*args, typeof(prev)); + next = va_arg(*args, typeof(next)); + + tracing_record_cmdline(prev); + + /* + * If tracer_switch_func only points to the local + * switch func, it still needs the ptr passed to it. + */ + wakeup_sched_switch(probe_data, __rq, prev, next); +} + +static void __wakeup_reset(struct trace_array *tr) +{ + struct trace_array_cpu *data; + int cpu; + + for_each_possible_cpu(cpu) { + data = tr->data[cpu]; + tracing_reset(data); + } + + wakeup_cpu = -1; + wakeup_prio = -1; + + if (wakeup_task) + put_task_struct(wakeup_task); + + wakeup_task = NULL; +} + +static void wakeup_reset(struct trace_array *tr) +{ + unsigned long flags; + + local_irq_save(flags); + __raw_spin_lock(&wakeup_lock); + __wakeup_reset(tr); + __raw_spin_unlock(&wakeup_lock); + local_irq_restore(flags); +} + +static void +wakeup_check_start(struct trace_array *tr, struct task_struct *p, + struct task_struct *curr) +{ + int cpu = smp_processor_id(); + unsigned long flags; + long disabled; + + if (likely(!rt_task(p)) || + p->prio >= wakeup_prio || + p->prio >= curr->prio) + return; + + disabled = atomic_inc_return(&tr->data[cpu]->disabled); + if (unlikely(disabled != 1)) + goto out; + + /* interrupts should be off from try_to_wake_up */ + __raw_spin_lock(&wakeup_lock); + + /* check for races. */ + if (!tracer_enabled || p->prio >= wakeup_prio) + goto out_locked; + + /* reset the trace */ + __wakeup_reset(tr); + + wakeup_cpu = task_cpu(p); + wakeup_prio = p->prio; + + wakeup_task = p; + get_task_struct(wakeup_task); + + local_save_flags(flags); + + tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); + trace_function(tr, tr->data[wakeup_cpu], + CALLER_ADDR1, CALLER_ADDR2, flags); + +out_locked: + __raw_spin_unlock(&wakeup_lock); +out: + atomic_dec(&tr->data[cpu]->disabled); +} + +static notrace void +wake_up_callback(void *probe_data, void *call_data, + const char *format, va_list *args) +{ + struct trace_array **ptr = probe_data; + struct trace_array *tr = *ptr; + struct task_struct *curr; + struct task_struct *task; + struct rq *__rq; + + if (likely(!tracer_enabled)) + return; + + /* Skip pid %d state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, long); + /* now get the meat: "rq %p task %p rq->curr %p" */ + __rq = va_arg(*args, typeof(__rq)); + task = va_arg(*args, typeof(task)); + curr = va_arg(*args, typeof(curr)); + + tracing_record_cmdline(task); + tracing_record_cmdline(curr); + + wakeup_check_start(tr, task, curr); +} + +static void start_wakeup_tracer(struct trace_array *tr) +{ + int ret; + + ret = marker_probe_register("kernel_sched_wakeup", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &wakeup_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup\n"); + return; + } + + ret = marker_probe_register("kernel_sched_wakeup_new", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &wakeup_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup_new\n"); + goto fail_deprobe; + } + + ret = marker_probe_register("kernel_sched_schedule", + "prev_pid %d next_pid %d prev_state %ld " + "## rq %p prev %p next %p", + sched_switch_callback, + &wakeup_trace); + if (ret) { + pr_info("sched trace: Couldn't add marker" + " probe to kernel_sched_schedule\n"); + goto fail_deprobe_wake_new; + } + + wakeup_reset(tr); + + /* + * Don't let the tracer_enabled = 1 show up before + * the wakeup_task is reset. This may be overkill since + * wakeup_reset does a spin_unlock after setting the + * wakeup_task to NULL, but I want to be safe. + * This is a slow path anyway. + */ + smp_wmb(); + + register_ftrace_function(&trace_ops); + + tracer_enabled = 1; + + return; +fail_deprobe_wake_new: + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &wakeup_trace); +fail_deprobe: + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &wakeup_trace); +} + +static void stop_wakeup_tracer(struct trace_array *tr) +{ + tracer_enabled = 0; + unregister_ftrace_function(&trace_ops); + marker_probe_unregister("kernel_sched_schedule", + sched_switch_callback, + &wakeup_trace); + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &wakeup_trace); + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &wakeup_trace); +} + +static void wakeup_tracer_init(struct trace_array *tr) +{ + wakeup_trace = tr; + + if (tr->ctrl) + start_wakeup_tracer(tr); +} + +static void wakeup_tracer_reset(struct trace_array *tr) +{ + if (tr->ctrl) { + stop_wakeup_tracer(tr); + /* make sure we put back any tasks we are tracing */ + wakeup_reset(tr); + } +} + +static void wakeup_tracer_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_wakeup_tracer(tr); + else + stop_wakeup_tracer(tr); +} + +static void wakeup_tracer_open(struct trace_iterator *iter) +{ + /* stop the trace while dumping */ + if (iter->tr->ctrl) + stop_wakeup_tracer(iter->tr); +} + +static void wakeup_tracer_close(struct trace_iterator *iter) +{ + /* forget about any processes we were recording */ + if (iter->tr->ctrl) + start_wakeup_tracer(iter->tr); +} + +static struct tracer wakeup_tracer __read_mostly = +{ + .name = "wakeup", + .init = wakeup_tracer_init, + .reset = wakeup_tracer_reset, + .open = wakeup_tracer_open, + .close = wakeup_tracer_close, + .ctrl_update = wakeup_tracer_ctrl_update, + .print_max = 1, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_wakeup, +#endif +}; + +__init static int init_wakeup_tracer(void) +{ + int ret; + + ret = register_tracer(&wakeup_tracer); + if (ret) + return ret; + + return 0; +} +device_initcall(init_wakeup_tracer); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c new file mode 100644 index 0000000..0911b7e --- /dev/null +++ b/kernel/trace/trace_selftest.c @@ -0,0 +1,563 @@ +/* Include in trace.c */ + +#include <linux/kthread.h> +#include <linux/delay.h> + +static inline int trace_valid_entry(struct trace_entry *entry) +{ + switch (entry->type) { + case TRACE_FN: + case TRACE_CTX: + case TRACE_WAKE: + case TRACE_STACK: + case TRACE_SPECIAL: + return 1; + } + return 0; +} + +static int +trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data) +{ + struct trace_entry *entries; + struct page *page; + int idx = 0; + int i; + + BUG_ON(list_empty(&data->trace_pages)); + page = list_entry(data->trace_pages.next, struct page, lru); + entries = page_address(page); + + check_pages(data); + if (head_page(data) != entries) + goto failed; + + /* + * The starting trace buffer always has valid elements, + * if any element exists. + */ + entries = head_page(data); + + for (i = 0; i < tr->entries; i++) { + + if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) { + printk(KERN_CONT ".. invalid entry %d ", + entries[idx].type); + goto failed; + } + + idx++; + if (idx >= ENTRIES_PER_PAGE) { + page = virt_to_page(entries); + if (page->lru.next == &data->trace_pages) { + if (i != tr->entries - 1) { + printk(KERN_CONT ".. entries buffer mismatch"); + goto failed; + } + } else { + page = list_entry(page->lru.next, struct page, lru); + entries = page_address(page); + } + idx = 0; + } + } + + page = virt_to_page(entries); + if (page->lru.next != &data->trace_pages) { + printk(KERN_CONT ".. too many entries"); + goto failed; + } + + return 0; + + failed: + /* disable tracing */ + tracing_disabled = 1; + printk(KERN_CONT ".. corrupted trace buffer .. "); + return -1; +} + +/* + * Test the trace buffer to see if all the elements + * are still sane. + */ +static int trace_test_buffer(struct trace_array *tr, unsigned long *count) +{ + unsigned long flags, cnt = 0; + int cpu, ret = 0; + + /* Don't allow flipping of max traces now */ + raw_local_irq_save(flags); + __raw_spin_lock(&ftrace_max_lock); + for_each_possible_cpu(cpu) { + if (!head_page(tr->data[cpu])) + continue; + + cnt += tr->data[cpu]->trace_idx; + + ret = trace_test_buffer_cpu(tr, tr->data[cpu]); + if (ret) + break; + } + __raw_spin_unlock(&ftrace_max_lock); + raw_local_irq_restore(flags); + + if (count) + *count = cnt; + + return ret; +} + +#ifdef CONFIG_FTRACE + +#ifdef CONFIG_DYNAMIC_FTRACE + +#define __STR(x) #x +#define STR(x) __STR(x) + +/* Test dynamic code modification and ftrace filters */ +int trace_selftest_startup_dynamic_tracing(struct tracer *trace, + struct trace_array *tr, + int (*func)(void)) +{ + unsigned long count; + int ret; + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + char *func_name; + + /* The ftrace test PASSED */ + printk(KERN_CONT "PASSED\n"); + pr_info("Testing dynamic ftrace: "); + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* passed in by parameter to fool gcc from optimizing */ + func(); + + /* update the records */ + ret = ftrace_force_update(); + if (ret) { + printk(KERN_CONT ".. ftraced failed .. "); + return ret; + } + + /* + * Some archs *cough*PowerPC*cough* add charachters to the + * start of the function names. We simply put a '*' to + * accomodate them. + */ + func_name = "*" STR(DYN_FTRACE_TEST_NAME); + + /* filter only on our function */ + ftrace_set_filter(func_name, strlen(func_name), 1); + + /* enable tracing */ + tr->ctrl = 1; + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + + /* we should have nothing in the buffer */ + ret = trace_test_buffer(tr, &count); + if (ret) + goto out; + + if (count) { + ret = -1; + printk(KERN_CONT ".. filter did not filter .. "); + goto out; + } + + /* call our function again */ + func(); + + /* sleep again */ + msleep(100); + + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + ftrace_enabled = 0; + + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + + /* we should only have one item */ + if (!ret && count != 1) { + printk(KERN_CONT ".. filter failed count=%ld ..", count); + ret = -1; + goto out; + } + out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + /* Enable tracing on all functions again */ + ftrace_set_filter(NULL, 0, 1); + + return ret; +} +#else +# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; }) +#endif /* CONFIG_DYNAMIC_FTRACE */ +/* + * Simple verification test of ftrace function tracer. + * Enable ftrace, sleep 1/10 second, and then read the trace + * buffer to see if all is in order. + */ +int +trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) +{ + unsigned long count; + int ret; + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + + /* make sure msleep has been recorded */ + msleep(1); + + /* force the recorded functions to be traced */ + ret = ftrace_force_update(); + if (ret) { + printk(KERN_CONT ".. ftraced failed .. "); + return ret; + } + + /* start the tracing */ + ftrace_enabled = 1; + tracer_enabled = 1; + + tr->ctrl = 1; + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + ftrace_enabled = 0; + + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + goto out; + } + + ret = trace_selftest_startup_dynamic_tracing(trace, tr, + DYN_FTRACE_TEST_NAME); + + out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + /* kill ftrace totally if we failed */ + if (ret) + ftrace_kill(); + + return ret; +} +#endif /* CONFIG_FTRACE */ + +#ifdef CONFIG_IRQSOFF_TRACER +int +trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) +{ + unsigned long save_max = tracing_max_latency; + unsigned long count; + int ret; + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + /* reset the max latency */ + tracing_max_latency = 0; + /* disable interrupts for a bit */ + local_irq_disable(); + udelay(100); + local_irq_enable(); + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check both trace buffers */ + ret = trace_test_buffer(tr, NULL); + if (!ret) + ret = trace_test_buffer(&max_tr, &count); + trace->reset(tr); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + + tracing_max_latency = save_max; + + return ret; +} +#endif /* CONFIG_IRQSOFF_TRACER */ + +#ifdef CONFIG_PREEMPT_TRACER +int +trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) +{ + unsigned long save_max = tracing_max_latency; + unsigned long count; + int ret; + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + /* reset the max latency */ + tracing_max_latency = 0; + /* disable preemption for a bit */ + preempt_disable(); + udelay(100); + preempt_enable(); + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check both trace buffers */ + ret = trace_test_buffer(tr, NULL); + if (!ret) + ret = trace_test_buffer(&max_tr, &count); + trace->reset(tr); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + + tracing_max_latency = save_max; + + return ret; +} +#endif /* CONFIG_PREEMPT_TRACER */ + +#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) +int +trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) +{ + unsigned long save_max = tracing_max_latency; + unsigned long count; + int ret; + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + + /* reset the max latency */ + tracing_max_latency = 0; + + /* disable preemption and interrupts for a bit */ + preempt_disable(); + local_irq_disable(); + udelay(100); + preempt_enable(); + /* reverse the order of preempt vs irqs */ + local_irq_enable(); + + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check both trace buffers */ + ret = trace_test_buffer(tr, NULL); + if (ret) + goto out; + + ret = trace_test_buffer(&max_tr, &count); + if (ret) + goto out; + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + goto out; + } + + /* do the test by disabling interrupts first this time */ + tracing_max_latency = 0; + tr->ctrl = 1; + trace->ctrl_update(tr); + preempt_disable(); + local_irq_disable(); + udelay(100); + preempt_enable(); + /* reverse the order of preempt vs irqs */ + local_irq_enable(); + + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check both trace buffers */ + ret = trace_test_buffer(tr, NULL); + if (ret) + goto out; + + ret = trace_test_buffer(&max_tr, &count); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + goto out; + } + + out: + trace->reset(tr); + tracing_max_latency = save_max; + + return ret; +} +#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */ + +#ifdef CONFIG_SCHED_TRACER +static int trace_wakeup_test_thread(void *data) +{ + /* Make this a RT thread, doesn't need to be too high */ + struct sched_param param = { .sched_priority = 5 }; + struct completion *x = data; + + sched_setscheduler(current, SCHED_FIFO, ¶m); + + /* Make it know we have a new prio */ + complete(x); + + /* now go to sleep and let the test wake us up */ + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + + /* we are awake, now wait to disappear */ + while (!kthread_should_stop()) { + /* + * This is an RT task, do short sleeps to let + * others run. + */ + msleep(100); + } + + return 0; +} + +int +trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) +{ + unsigned long save_max = tracing_max_latency; + struct task_struct *p; + struct completion isrt; + unsigned long count; + int ret; + + init_completion(&isrt); + + /* create a high prio thread */ + p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test"); + if (IS_ERR(p)) { + printk(KERN_CONT "Failed to create ftrace wakeup test thread "); + return -1; + } + + /* make sure the thread is running at an RT prio */ + wait_for_completion(&isrt); + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + /* reset the max latency */ + tracing_max_latency = 0; + + /* sleep to let the RT thread sleep too */ + msleep(100); + + /* + * Yes this is slightly racy. It is possible that for some + * strange reason that the RT thread we created, did not + * call schedule for 100ms after doing the completion, + * and we do a wakeup on a task that already is awake. + * But that is extremely unlikely, and the worst thing that + * happens in such a case, is that we disable tracing. + * Honestly, if this race does happen something is horrible + * wrong with the system. + */ + + wake_up_process(p); + + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check both trace buffers */ + ret = trace_test_buffer(tr, NULL); + if (!ret) + ret = trace_test_buffer(&max_tr, &count); + + + trace->reset(tr); + + tracing_max_latency = save_max; + + /* kill the thread */ + kthread_stop(p); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + + return ret; +} +#endif /* CONFIG_SCHED_TRACER */ + +#ifdef CONFIG_CONTEXT_SWITCH_TRACER +int +trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr) +{ + unsigned long count; + int ret; + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + + if (!ret && !count) { + printk(KERN_CONT ".. no entries found .."); + ret = -1; + } + + return ret; +} +#endif /* CONFIG_CONTEXT_SWITCH_TRACER */ + +#ifdef CONFIG_SYSPROF_TRACER +int +trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr) +{ + unsigned long count; + int ret; + + /* start the tracing */ + tr->ctrl = 1; + trace->init(tr); + /* Sleep for a 1/10 of a second */ + msleep(100); + /* stop the tracing. */ + tr->ctrl = 0; + trace->ctrl_update(tr); + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + + return ret; +} +#endif /* CONFIG_SYSPROF_TRACER */ diff --git a/kernel/trace/trace_selftest_dynamic.c b/kernel/trace/trace_selftest_dynamic.c new file mode 100644 index 0000000..54dd77c --- /dev/null +++ b/kernel/trace/trace_selftest_dynamic.c @@ -0,0 +1,7 @@ +#include "trace.h" + +int DYN_FTRACE_TEST_NAME(void) +{ + /* used to call mcount */ + return 0; +} diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c new file mode 100644 index 0000000..db58fb6 --- /dev/null +++ b/kernel/trace/trace_sysprof.c @@ -0,0 +1,363 @@ +/* + * trace stack traces + * + * Copyright (C) 2004-2008, Soeren Sandmann + * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + */ +#include <linux/kallsyms.h> +#include <linux/debugfs.h> +#include <linux/hrtimer.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/module.h> +#include <linux/irq.h> +#include <linux/fs.h> + +#include <asm/stacktrace.h> + +#include "trace.h" + +static struct trace_array *sysprof_trace; +static int __read_mostly tracer_enabled; + +/* + * 1 msec sample interval by default: + */ +static unsigned long sample_period = 1000000; +static const unsigned int sample_max_depth = 512; + +static DEFINE_MUTEX(sample_timer_lock); +/* + * Per CPU hrtimers that do the profiling: + */ +static DEFINE_PER_CPU(struct hrtimer, stack_trace_hrtimer); + +struct stack_frame { + const void __user *next_fp; + unsigned long return_address; +}; + +static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) +{ + int ret; + + if (!access_ok(VERIFY_READ, fp, sizeof(*frame))) + return 0; + + ret = 1; + pagefault_disable(); + if (__copy_from_user_inatomic(frame, fp, sizeof(*frame))) + ret = 0; + pagefault_enable(); + + return ret; +} + +struct backtrace_info { + struct trace_array_cpu *data; + struct trace_array *tr; + int pos; +}; + +static void +backtrace_warning_symbol(void *data, char *msg, unsigned long symbol) +{ + /* Ignore warnings */ +} + +static void backtrace_warning(void *data, char *msg) +{ + /* Ignore warnings */ +} + +static int backtrace_stack(void *data, char *name) +{ + /* Don't bother with IRQ stacks for now */ + return -1; +} + +static void backtrace_address(void *data, unsigned long addr, int reliable) +{ + struct backtrace_info *info = data; + + if (info->pos < sample_max_depth && reliable) { + __trace_special(info->tr, info->data, 1, addr, 0); + + info->pos++; + } +} + +const static struct stacktrace_ops backtrace_ops = { + .warning = backtrace_warning, + .warning_symbol = backtrace_warning_symbol, + .stack = backtrace_stack, + .address = backtrace_address, +}; + +static int +trace_kernel(struct pt_regs *regs, struct trace_array *tr, + struct trace_array_cpu *data) +{ + struct backtrace_info info; + unsigned long bp; + char *stack; + + info.tr = tr; + info.data = data; + info.pos = 1; + + __trace_special(info.tr, info.data, 1, regs->ip, 0); + + stack = ((char *)regs + sizeof(struct pt_regs)); +#ifdef CONFIG_FRAME_POINTER + bp = regs->bp; +#else + bp = 0; +#endif + + dump_trace(NULL, regs, (void *)stack, bp, &backtrace_ops, &info); + + return info.pos; +} + +static void timer_notify(struct pt_regs *regs, int cpu) +{ + struct trace_array_cpu *data; + struct stack_frame frame; + struct trace_array *tr; + const void __user *fp; + int is_user; + int i; + + if (!regs) + return; + + tr = sysprof_trace; + data = tr->data[cpu]; + is_user = user_mode(regs); + + if (!current || current->pid == 0) + return; + + if (is_user && current->state != TASK_RUNNING) + return; + + __trace_special(tr, data, 0, 0, current->pid); + + if (!is_user) + i = trace_kernel(regs, tr, data); + else + i = 0; + + /* + * Trace user stack if we are not a kernel thread + */ + if (current->mm && i < sample_max_depth) { + regs = (struct pt_regs *)current->thread.sp0 - 1; + + fp = (void __user *)regs->bp; + + __trace_special(tr, data, 2, regs->ip, 0); + + while (i < sample_max_depth) { + frame.next_fp = NULL; + frame.return_address = 0; + if (!copy_stack_frame(fp, &frame)) + break; + if ((unsigned long)fp < regs->sp) + break; + + __trace_special(tr, data, 2, frame.return_address, + (unsigned long)fp); + fp = frame.next_fp; + + i++; + } + + } + + /* + * Special trace entry if we overflow the max depth: + */ + if (i == sample_max_depth) + __trace_special(tr, data, -1, -1, -1); + + __trace_special(tr, data, 3, current->pid, i); +} + +static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer) +{ + /* trace here */ + timer_notify(get_irq_regs(), smp_processor_id()); + + hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period)); + + return HRTIMER_RESTART; +} + +static void start_stack_timer(int cpu) +{ + struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu); + + hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer->function = stack_trace_timer_fn; + hrtimer->cb_mode = HRTIMER_CB_IRQSAFE_PERCPU; + + hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL); +} + +static void start_stack_timers(void) +{ + cpumask_t saved_mask = current->cpus_allowed; + int cpu; + + for_each_online_cpu(cpu) { + set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); + start_stack_timer(cpu); + } + set_cpus_allowed_ptr(current, &saved_mask); +} + +static void stop_stack_timer(int cpu) +{ + struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu); + + hrtimer_cancel(hrtimer); +} + +static void stop_stack_timers(void) +{ + int cpu; + + for_each_online_cpu(cpu) + stop_stack_timer(cpu); +} + +static void stack_reset(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); +} + +static void start_stack_trace(struct trace_array *tr) +{ + mutex_lock(&sample_timer_lock); + stack_reset(tr); + start_stack_timers(); + tracer_enabled = 1; + mutex_unlock(&sample_timer_lock); +} + +static void stop_stack_trace(struct trace_array *tr) +{ + mutex_lock(&sample_timer_lock); + stop_stack_timers(); + tracer_enabled = 0; + mutex_unlock(&sample_timer_lock); +} + +static void stack_trace_init(struct trace_array *tr) +{ + sysprof_trace = tr; + + if (tr->ctrl) + start_stack_trace(tr); +} + +static void stack_trace_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_stack_trace(tr); +} + +static void stack_trace_ctrl_update(struct trace_array *tr) +{ + /* When starting a new trace, reset the buffers */ + if (tr->ctrl) + start_stack_trace(tr); + else + stop_stack_trace(tr); +} + +static struct tracer stack_trace __read_mostly = +{ + .name = "sysprof", + .init = stack_trace_init, + .reset = stack_trace_reset, + .ctrl_update = stack_trace_ctrl_update, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_sysprof, +#endif +}; + +__init static int init_stack_trace(void) +{ + return register_tracer(&stack_trace); +} +device_initcall(init_stack_trace); + +#define MAX_LONG_DIGITS 22 + +static ssize_t +sysprof_sample_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[MAX_LONG_DIGITS]; + int r; + + r = sprintf(buf, "%ld\n", nsecs_to_usecs(sample_period)); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +sysprof_sample_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[MAX_LONG_DIGITS]; + unsigned long val; + + if (cnt > MAX_LONG_DIGITS-1) + cnt = MAX_LONG_DIGITS-1; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + val = simple_strtoul(buf, NULL, 10); + /* + * Enforce a minimum sample period of 100 usecs: + */ + if (val < 100) + val = 100; + + mutex_lock(&sample_timer_lock); + stop_stack_timers(); + sample_period = val * 1000; + start_stack_timers(); + mutex_unlock(&sample_timer_lock); + + return cnt; +} + +static struct file_operations sysprof_sample_fops = { + .read = sysprof_sample_read, + .write = sysprof_sample_write, +}; + +void init_tracer_sysprof_debugfs(struct dentry *d_tracer) +{ + struct dentry *entry; + + entry = debugfs_create_file("sysprof_sample_period", 0644, + d_tracer, NULL, &sysprof_sample_fops); + if (entry) + return; + pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n"); +} diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 4ab1b58..8ebcd85 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -28,14 +28,14 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) { struct timespec uptime, ts; - s64 ac_etime; + u64 ac_etime; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); /* calculate task elapsed time in timespec */ do_posix_clock_monotonic_gettime(&uptime); ts = timespec_sub(uptime, tsk->start_time); - /* rebase elapsed time to usec */ + /* rebase elapsed time to usec (should never be negative) */ ac_etime = timespec_to_ns(&ts); do_div(ac_etime, NSEC_PER_USEC); stats->ac_etime = ac_etime; @@ -84,9 +84,9 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) { struct mm_struct *mm; - /* convert pages-jiffies to Mbyte-usec */ - stats->coremem = jiffies_to_usecs(p->acct_rss_mem1) * PAGE_SIZE / MB; - stats->virtmem = jiffies_to_usecs(p->acct_vm_mem1) * PAGE_SIZE / MB; + /* convert pages-usec to Mbyte-usec */ + stats->coremem = p->acct_rss_mem1 * PAGE_SIZE / MB; + stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB; mm = get_task_mm(p); if (mm) { /* adjust to KB unit */ @@ -94,10 +94,10 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) stats->hiwater_vm = mm->hiwater_vm * PAGE_SIZE / KB; mmput(mm); } - stats->read_char = p->rchar; - stats->write_char = p->wchar; - stats->read_syscalls = p->syscr; - stats->write_syscalls = p->syscw; + stats->read_char = p->ioac.rchar; + stats->write_char = p->ioac.wchar; + stats->read_syscalls = p->ioac.syscr; + stats->write_syscalls = p->ioac.syscw; #ifdef CONFIG_TASK_IO_ACCOUNTING stats->read_bytes = p->ioac.read_bytes; stats->write_bytes = p->ioac.write_bytes; @@ -118,12 +118,19 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) void acct_update_integrals(struct task_struct *tsk) { if (likely(tsk->mm)) { - long delta = cputime_to_jiffies( - cputime_sub(tsk->stime, tsk->acct_stimexpd)); + cputime_t time, dtime; + struct timeval value; + u64 delta; + + time = tsk->stime + tsk->utime; + dtime = cputime_sub(time, tsk->acct_timexpd); + jiffies_to_timeval(cputime_to_jiffies(dtime), &value); + delta = value.tv_sec; + delta = delta * USEC_PER_SEC + value.tv_usec; if (delta == 0) return; - tsk->acct_stimexpd = tsk->stime; + tsk->acct_timexpd = time; tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm); tsk->acct_vm_mem1 += delta * tsk->mm->total_vm; } @@ -135,7 +142,7 @@ void acct_update_integrals(struct task_struct *tsk) */ void acct_clear_integrals(struct task_struct *tsk) { - tsk->acct_stimexpd = 0; + tsk->acct_timexpd = 0; tsk->acct_rss_mem1 = 0; tsk->acct_vm_mem1 = 0; } diff --git a/kernel/user.c b/kernel/user.c index 865ecf57..39d6159 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -169,7 +169,7 @@ static ssize_t cpu_rt_runtime_show(struct kobject *kobj, { struct user_struct *up = container_of(kobj, struct user_struct, kobj); - return sprintf(buf, "%lu\n", sched_group_rt_runtime(up->tg)); + return sprintf(buf, "%ld\n", sched_group_rt_runtime(up->tg)); } static ssize_t cpu_rt_runtime_store(struct kobject *kobj, @@ -180,7 +180,7 @@ static ssize_t cpu_rt_runtime_store(struct kobject *kobj, unsigned long rt_runtime; int rc; - sscanf(buf, "%lu", &rt_runtime); + sscanf(buf, "%ld", &rt_runtime); rc = sched_group_set_rt_runtime(up->tg, rt_runtime); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index a9ab059..532858f 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -6,7 +6,6 @@ */ #include <linux/module.h> -#include <linux/version.h> #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/user_namespace.h> diff --git a/kernel/utsname.c b/kernel/utsname.c index 64d398f..815237a 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -12,7 +12,6 @@ #include <linux/module.h> #include <linux/uts.h> #include <linux/utsname.h> -#include <linux/version.h> #include <linux/err.h> #include <linux/slab.h> diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c index fe3a56c..4ab9659 100644 --- a/kernel/utsname_sysctl.c +++ b/kernel/utsname_sysctl.c @@ -12,7 +12,6 @@ #include <linux/module.h> #include <linux/uts.h> #include <linux/utsname.h> -#include <linux/version.h> #include <linux/sysctl.h> static void *get_uts(ctl_table *table, int write) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 29fc39f..4048e92 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -13,7 +13,7 @@ * Kai Petzke <wpp@marie.physik.tu-berlin.de> * Theodore Ts'o <tytso@mit.edu> * - * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>. + * Made to use alloc_percpu by Christoph Lameter. */ #include <linux/module.h> @@ -125,7 +125,7 @@ struct cpu_workqueue_struct *get_wq_data(struct work_struct *work) } static void insert_work(struct cpu_workqueue_struct *cwq, - struct work_struct *work, int tail) + struct work_struct *work, struct list_head *head) { set_wq_data(work, cwq); /* @@ -133,21 +133,17 @@ static void insert_work(struct cpu_workqueue_struct *cwq, * result of list_add() below, see try_to_grab_pending(). */ smp_wmb(); - if (tail) - list_add_tail(&work->entry, &cwq->worklist); - else - list_add(&work->entry, &cwq->worklist); + list_add_tail(&work->entry, head); wake_up(&cwq->more_work); } -/* Preempt must be disabled. */ static void __queue_work(struct cpu_workqueue_struct *cwq, struct work_struct *work) { unsigned long flags; spin_lock_irqsave(&cwq->lock, flags); - insert_work(cwq, work, 1); + insert_work(cwq, work, &cwq->worklist); spin_unlock_irqrestore(&cwq->lock, flags); } @@ -163,17 +159,39 @@ static void __queue_work(struct cpu_workqueue_struct *cwq, */ int queue_work(struct workqueue_struct *wq, struct work_struct *work) { + int ret; + + ret = queue_work_on(get_cpu(), wq, work); + put_cpu(); + + return ret; +} +EXPORT_SYMBOL_GPL(queue_work); + +/** + * queue_work_on - queue work on specific cpu + * @cpu: CPU number to execute work on + * @wq: workqueue to use + * @work: work to queue + * + * Returns 0 if @work was already on a queue, non-zero otherwise. + * + * We queue the work to a specific CPU, the caller must ensure it + * can't go away. + */ +int +queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work) +{ int ret = 0; if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { BUG_ON(!list_empty(&work->entry)); - __queue_work(wq_per_cpu(wq, get_cpu()), work); - put_cpu(); + __queue_work(wq_per_cpu(wq, cpu), work); ret = 1; } return ret; } -EXPORT_SYMBOL_GPL(queue_work); +EXPORT_SYMBOL_GPL(queue_work_on); static void delayed_work_timer_fn(unsigned long __data) { @@ -272,11 +290,11 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) BUG_ON(get_wq_data(work) != cwq); work_clear_pending(work); - lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); - lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_); + lock_map_acquire(&cwq->wq->lockdep_map); + lock_map_acquire(&lockdep_map); f(work); - lock_release(&lockdep_map, 1, _THIS_IP_); - lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_); + lock_map_release(&lockdep_map); + lock_map_release(&cwq->wq->lockdep_map); if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " @@ -337,14 +355,14 @@ static void wq_barrier_func(struct work_struct *work) } static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, - struct wq_barrier *barr, int tail) + struct wq_barrier *barr, struct list_head *head) { INIT_WORK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work)); init_completion(&barr->done); - insert_work(cwq, &barr->work, tail); + insert_work(cwq, &barr->work, head); } static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) @@ -364,7 +382,7 @@ static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) active = 0; spin_lock_irq(&cwq->lock); if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) { - insert_wq_barrier(cwq, &barr, 1); + insert_wq_barrier(cwq, &barr, &cwq->worklist); active = 1; } spin_unlock_irq(&cwq->lock); @@ -395,13 +413,64 @@ void flush_workqueue(struct workqueue_struct *wq) int cpu; might_sleep(); - lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); - lock_release(&wq->lockdep_map, 1, _THIS_IP_); - for_each_cpu_mask(cpu, *cpu_map) + lock_map_acquire(&wq->lockdep_map); + lock_map_release(&wq->lockdep_map); + for_each_cpu_mask_nr(cpu, *cpu_map) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); } EXPORT_SYMBOL_GPL(flush_workqueue); +/** + * flush_work - block until a work_struct's callback has terminated + * @work: the work which is to be flushed + * + * Returns false if @work has already terminated. + * + * It is expected that, prior to calling flush_work(), the caller has + * arranged for the work to not be requeued, otherwise it doesn't make + * sense to use this function. + */ +int flush_work(struct work_struct *work) +{ + struct cpu_workqueue_struct *cwq; + struct list_head *prev; + struct wq_barrier barr; + + might_sleep(); + cwq = get_wq_data(work); + if (!cwq) + return 0; + + lock_map_acquire(&cwq->wq->lockdep_map); + lock_map_release(&cwq->wq->lockdep_map); + + prev = NULL; + spin_lock_irq(&cwq->lock); + if (!list_empty(&work->entry)) { + /* + * See the comment near try_to_grab_pending()->smp_rmb(). + * If it was re-queued under us we are not going to wait. + */ + smp_rmb(); + if (unlikely(cwq != get_wq_data(work))) + goto out; + prev = &work->entry; + } else { + if (cwq->current_work != work) + goto out; + prev = &cwq->worklist; + } + insert_wq_barrier(cwq, &barr, prev->next); +out: + spin_unlock_irq(&cwq->lock); + if (!prev) + return 0; + + wait_for_completion(&barr.done); + return 1; +} +EXPORT_SYMBOL_GPL(flush_work); + /* * Upon a successful return (>= 0), the caller "owns" WORK_STRUCT_PENDING bit, * so this work can't be re-armed in any way. @@ -449,7 +518,7 @@ static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq, spin_lock_irq(&cwq->lock); if (unlikely(cwq->current_work == work)) { - insert_wq_barrier(cwq, &barr, 0); + insert_wq_barrier(cwq, &barr, cwq->worklist.next); running = 1; } spin_unlock_irq(&cwq->lock); @@ -467,8 +536,8 @@ static void wait_on_work(struct work_struct *work) might_sleep(); - lock_acquire(&work->lockdep_map, 0, 0, 0, 2, _THIS_IP_); - lock_release(&work->lockdep_map, 1, _THIS_IP_); + lock_map_acquire(&work->lockdep_map); + lock_map_release(&work->lockdep_map); cwq = get_wq_data(work); if (!cwq) @@ -477,7 +546,7 @@ static void wait_on_work(struct work_struct *work) wq = cwq->wq; cpu_map = wq_cpu_map(wq); - for_each_cpu_mask(cpu, *cpu_map) + for_each_cpu_mask_nr(cpu, *cpu_map) wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work); } @@ -553,6 +622,19 @@ int schedule_work(struct work_struct *work) } EXPORT_SYMBOL(schedule_work); +/* + * schedule_work_on - put work task on a specific cpu + * @cpu: cpu to put the work task on + * @work: job to be done + * + * This puts a job on a specific cpu + */ +int schedule_work_on(int cpu, struct work_struct *work) +{ + return queue_work_on(cpu, keventd_wq, work); +} +EXPORT_SYMBOL(schedule_work_on); + /** * schedule_delayed_work - put work task in global workqueue after delay * @dwork: job to be done @@ -607,10 +689,10 @@ int schedule_on_each_cpu(work_func_t func) struct work_struct *work = per_cpu_ptr(works, cpu); INIT_WORK(work, func); - set_bit(WORK_STRUCT_PENDING, work_data_bits(work)); - __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work); + schedule_work_on(cpu, work); } - flush_workqueue(keventd_wq); + for_each_online_cpu(cpu) + flush_work(per_cpu_ptr(works, cpu)); put_online_cpus(); free_percpu(works); return 0; @@ -747,11 +829,22 @@ struct workqueue_struct *__create_workqueue_key(const char *name, err = create_workqueue_thread(cwq, singlethread_cpu); start_workqueue_thread(cwq, -1); } else { - get_online_cpus(); + cpu_maps_update_begin(); + /* + * We must place this wq on list even if the code below fails. + * cpu_down(cpu) can remove cpu from cpu_populated_map before + * destroy_workqueue() takes the lock, in that case we leak + * cwq[cpu]->thread. + */ spin_lock(&workqueue_lock); list_add(&wq->list, &workqueues); spin_unlock(&workqueue_lock); - + /* + * We must initialize cwqs for each possible cpu even if we + * are going to call destroy_workqueue() finally. Otherwise + * cpu_up() can hit the uninitialized cwq once we drop the + * lock. + */ for_each_possible_cpu(cpu) { cwq = init_cpu_workqueue(wq, cpu); if (err || !cpu_online(cpu)) @@ -759,7 +852,7 @@ struct workqueue_struct *__create_workqueue_key(const char *name, err = create_workqueue_thread(cwq, cpu); start_workqueue_thread(cwq, cpu); } - put_online_cpus(); + cpu_maps_update_done(); } if (err) { @@ -773,18 +866,18 @@ EXPORT_SYMBOL_GPL(__create_workqueue_key); static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq) { /* - * Our caller is either destroy_workqueue() or CPU_DEAD, - * get_online_cpus() protects cwq->thread. + * Our caller is either destroy_workqueue() or CPU_POST_DEAD, + * cpu_add_remove_lock protects cwq->thread. */ if (cwq->thread == NULL) return; - lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); - lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_); + lock_map_acquire(&cwq->wq->lockdep_map); + lock_map_release(&cwq->wq->lockdep_map); flush_cpu_workqueue(cwq); /* - * If the caller is CPU_DEAD and cwq->worklist was not empty, + * If the caller is CPU_POST_DEAD and cwq->worklist was not empty, * a concurrent flush_workqueue() can insert a barrier after us. * However, in that case run_workqueue() won't return and check * kthread_should_stop() until it flushes all work_struct's. @@ -808,14 +901,14 @@ void destroy_workqueue(struct workqueue_struct *wq) const cpumask_t *cpu_map = wq_cpu_map(wq); int cpu; - get_online_cpus(); + cpu_maps_update_begin(); spin_lock(&workqueue_lock); list_del(&wq->list); spin_unlock(&workqueue_lock); - for_each_cpu_mask(cpu, *cpu_map) + for_each_cpu_mask_nr(cpu, *cpu_map) cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu)); - put_online_cpus(); + cpu_maps_update_done(); free_percpu(wq->cpu_wq); kfree(wq); @@ -829,6 +922,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, unsigned int cpu = (unsigned long)hcpu; struct cpu_workqueue_struct *cwq; struct workqueue_struct *wq; + int ret = NOTIFY_OK; action &= ~CPU_TASKS_FROZEN; @@ -836,7 +930,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, case CPU_UP_PREPARE: cpu_set(cpu, cpu_populated_map); } - +undo: list_for_each_entry(wq, &workqueues, list) { cwq = per_cpu_ptr(wq->cpu_wq, cpu); @@ -846,7 +940,9 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, break; printk(KERN_ERR "workqueue [%s] for %i failed\n", wq->name, cpu); - return NOTIFY_BAD; + action = CPU_UP_CANCELED; + ret = NOTIFY_BAD; + goto undo; case CPU_ONLINE: start_workqueue_thread(cwq, cpu); @@ -854,7 +950,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, case CPU_UP_CANCELED: start_workqueue_thread(cwq, -1); - case CPU_DEAD: + case CPU_POST_DEAD: cleanup_workqueue_thread(cwq); break; } @@ -862,11 +958,11 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, switch (action) { case CPU_UP_CANCELED: - case CPU_DEAD: + case CPU_POST_DEAD: cpu_clear(cpu, cpu_populated_map); } - return NOTIFY_OK; + return ret; } void __init init_workqueues(void) |
