diff options
| -rw-r--r-- | include/linux/delayacct.h | 15 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | include/linux/taskstats.h | 55 | ||||
| -rw-r--r-- | include/linux/taskstats_kern.h | 1 | ||||
| -rw-r--r-- | init/Kconfig | 1 | ||||
| -rw-r--r-- | kernel/delayacct.c | 62 | ||||
| -rw-r--r-- | kernel/taskstats.c | 16 |
7 files changed, 144 insertions, 7 deletions
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 0ecbf9a..d955078 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -18,6 +18,7 @@ #define _LINUX_DELAYACCT_H #include <linux/sched.h> +#include <linux/taskstats_kern.h> /* * Per-task flags relevant to delay accounting @@ -35,6 +36,7 @@ extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); extern void __delayacct_blkio_end(void); +extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); static inline void delayacct_set_flag(int flag) { @@ -74,6 +76,16 @@ static inline void delayacct_blkio_end(void) __delayacct_blkio_end(); } +static inline int delayacct_add_tsk(struct taskstats *d, + struct task_struct *tsk) +{ + if (likely(!delayacct_on)) + return -EINVAL; + if (!tsk->delays) + return 0; + return __delayacct_add_tsk(d, tsk); +} + #else static inline void delayacct_set_flag(int flag) {} @@ -89,6 +101,9 @@ static inline void delayacct_blkio_start(void) {} static inline void delayacct_blkio_end(void) {} +static inline int delayacct_add_tsk(struct taskstats *d, + struct task_struct *tsk) +{ return 0; } #endif /* CONFIG_TASK_DELAY_ACCT */ #endif diff --git a/include/linux/sched.h b/include/linux/sched.h index f751062..3c5610c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -990,6 +990,7 @@ struct task_struct { */ struct pipe_inode_info *splice_pipe; #ifdef CONFIG_TASK_DELAY_ACCT + spinlock_t delays_lock; struct task_delay_info *delays; #endif }; diff --git a/include/linux/taskstats.h b/include/linux/taskstats.h index 51f6275..c6aeca3 100644 --- a/include/linux/taskstats.h +++ b/include/linux/taskstats.h @@ -34,7 +34,60 @@ struct taskstats { /* Version 1 */ - __u64 version; + __u16 version; + __u16 padding[3]; /* Userspace should not interpret the padding + * field which can be replaced by useful + * fields if struct taskstats is extended. + */ + + /* Delay accounting fields start + * + * All values, until comment "Delay accounting fields end" are + * available only if delay accounting is enabled, even though the last + * few fields are not delays + * + * xxx_count is the number of delay values recorded + * xxx_delay_total is the corresponding cumulative delay in nanoseconds + * + * xxx_delay_total wraps around to zero on overflow + * xxx_count incremented regardless of overflow + */ + + /* Delay waiting for cpu, while runnable + * count, delay_total NOT updated atomically + */ + __u64 cpu_count; + __u64 cpu_delay_total; + + /* Following four fields atomically updated using task->delays->lock */ + + /* Delay waiting for synchronous block I/O to complete + * does not account for delays in I/O submission + */ + __u64 blkio_count; + __u64 blkio_delay_total; + + /* Delay waiting for page fault I/O (swap in only) */ + __u64 swapin_count; + __u64 swapin_delay_total; + + /* cpu "wall-clock" running time + * On some architectures, value will adjust for cpu time stolen + * from the kernel in involuntary waits due to virtualization. + * Value is cumulative, in nanoseconds, without a corresponding count + * and wraps around to zero silently on overflow + */ + __u64 cpu_run_real_total; + + /* cpu "virtual" running time + * Uses time intervals seen by the kernel i.e. no adjustment + * for kernel's involuntary waits due to virtualization. + * Value is cumulative, in nanoseconds, without a corresponding count + * and wraps around to zero silently on overflow + */ + __u64 cpu_run_virtual_total; + /* Delay accounting fields end */ + /* version 1 ends here */ }; diff --git a/include/linux/taskstats_kern.h b/include/linux/taskstats_kern.h index bd0ecb96..fc9da2e 100644 --- a/include/linux/taskstats_kern.h +++ b/include/linux/taskstats_kern.h @@ -17,6 +17,7 @@ enum { #ifdef CONFIG_TASKSTATS extern kmem_cache_t *taskstats_cache; +extern struct mutex taskstats_exit_mutex; static inline void taskstats_exit_alloc(struct taskstats **ptidstats, struct taskstats **ptgidstats) diff --git a/init/Kconfig b/init/Kconfig index 56a7093..a099fc6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -173,6 +173,7 @@ config TASKSTATS config TASK_DELAY_ACCT bool "Enable per-task delay accounting (EXPERIMENTAL)" + depends on TASKSTATS help Collect information on time spent by a task waiting for system resources like cpu, synchronous block I/O completion and swapping diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 3546b08..1be274a 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -41,6 +41,10 @@ void delayacct_init(void) void __delayacct_tsk_init(struct task_struct *tsk) { + spin_lock_init(&tsk->delays_lock); + /* No need to acquire tsk->delays_lock for allocation here unless + __delayacct_tsk_init called after tsk is attached to tasklist + */ tsk->delays = kmem_cache_zalloc(delayacct_cache, SLAB_KERNEL); if (tsk->delays) spin_lock_init(&tsk->delays->lock); @@ -48,8 +52,11 @@ void __delayacct_tsk_init(struct task_struct *tsk) void __delayacct_tsk_exit(struct task_struct *tsk) { - kmem_cache_free(delayacct_cache, tsk->delays); + struct task_delay_info *delays = tsk->delays; + spin_lock(&tsk->delays_lock); tsk->delays = NULL; + spin_unlock(&tsk->delays_lock); + kmem_cache_free(delayacct_cache, delays); } /* @@ -104,3 +111,56 @@ void __delayacct_blkio_end(void) ¤t->delays->blkio_delay, ¤t->delays->blkio_count); } + +int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) +{ + s64 tmp; + struct timespec ts; + unsigned long t1,t2,t3; + + spin_lock(&tsk->delays_lock); + + /* Though tsk->delays accessed later, early exit avoids + * unnecessary returning of other data + */ + if (!tsk->delays) + goto done; + + tmp = (s64)d->cpu_run_real_total; + cputime_to_timespec(tsk->utime + tsk->stime, &ts); + tmp += timespec_to_ns(&ts); + d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; + + /* + * No locking available for sched_info (and too expensive to add one) + * Mitigate by taking snapshot of values + */ + t1 = tsk->sched_info.pcnt; + t2 = tsk->sched_info.run_delay; + t3 = tsk->sched_info.cpu_time; + + d->cpu_count += t1; + + jiffies_to_timespec(t2, &ts); + tmp = (s64)d->cpu_delay_total + timespec_to_ns(&ts); + d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; + + tmp = (s64)d->cpu_run_virtual_total + (s64)jiffies_to_usecs(t3) * 1000; + d->cpu_run_virtual_total = + (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; + + /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ + + spin_lock(&tsk->delays->lock); + tmp = d->blkio_delay_total + tsk->delays->blkio_delay; + 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; + d->blkio_count += tsk->delays->blkio_count; + d->swapin_count += tsk->delays->swapin_count; + spin_unlock(&tsk->delays->lock); + +done: + spin_unlock(&tsk->delays_lock); + return 0; +} diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 82ec913..ea9506d 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -18,13 +18,13 @@ #include <linux/kernel.h> #include <linux/taskstats_kern.h> +#include <linux/delayacct.h> #include <net/genetlink.h> #include <asm/atomic.h> static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; static int family_registered; kmem_cache_t *taskstats_cache; -static DEFINE_MUTEX(taskstats_exit_mutex); static struct genl_family family = { .id = GENL_ID_GENERATE, @@ -120,7 +120,10 @@ static int fill_pid(pid_t pid, struct task_struct *pidtsk, * goto err; */ -err: + rc = delayacct_add_tsk(stats, tsk); + stats->version = TASKSTATS_VERSION; + + /* Define err: label here if needed */ put_task_struct(tsk); return rc; @@ -152,8 +155,14 @@ static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, * break; */ + rc = delayacct_add_tsk(stats, tsk); + if (rc) + break; + } while_each_thread(first, tsk); read_unlock(&tasklist_lock); + stats->version = TASKSTATS_VERSION; + /* * Accounting subsytems can also add calls here if they don't @@ -233,8 +242,6 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, if (!family_registered || !tidstats) return; - mutex_lock(&taskstats_exit_mutex); - is_thread_group = !thread_group_empty(tsk); rc = 0; @@ -292,7 +299,6 @@ nla_put_failure: err_skb: nlmsg_free(rep_skb); ret: - mutex_unlock(&taskstats_exit_mutex); return; } |
