diff options
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/Makefile | 2 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-internal.h | 13 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 14 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 111 | ||||
| -rw-r--r-- | kernel/cgroup/rdma.c | 35 | ||||
| -rw-r--r-- | kernel/cgroup/rstat.c | 416 | ||||
| -rw-r--r-- | kernel/cgroup/stat.c | 338 |
7 files changed, 517 insertions, 412 deletions
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile index 2be89a00..bfcdae8 100644 --- a/kernel/cgroup/Makefile +++ b/kernel/cgroup/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-y := cgroup.o stat.o namespace.o cgroup-v1.o +obj-y := cgroup.o rstat.o namespace.o cgroup-v1.o obj-$(CONFIG_CGROUP_FREEZER) += freezer.o obj-$(CONFIG_CGROUP_PIDS) += pids.o diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index b928b27..77ff1cd 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -201,13 +201,12 @@ int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, int cgroup_task_count(const struct cgroup *cgrp); /* - * stat.c + * rstat.c */ -void cgroup_stat_flush(struct cgroup *cgrp); -int cgroup_stat_init(struct cgroup *cgrp); -void cgroup_stat_exit(struct cgroup *cgrp); -void cgroup_stat_show_cputime(struct seq_file *seq); -void cgroup_stat_boot(void); +int cgroup_rstat_init(struct cgroup *cgrp); +void cgroup_rstat_exit(struct cgroup *cgrp); +void cgroup_rstat_boot(void); +void cgroup_base_stat_cputime_show(struct seq_file *seq); /* * namespace.c @@ -218,9 +217,9 @@ extern const struct proc_ns_operations cgroupns_operations; * cgroup-v1.c */ extern struct cftype cgroup1_base_files[]; -extern const struct file_operations proc_cgroupstats_operations; extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops; +int proc_cgroupstats_show(struct seq_file *m, void *v); bool cgroup1_ssid_disabled(int ssid); void cgroup1_pidlist_destroy_all(struct cgroup *cgrp); void cgroup1_release_agent(struct work_struct *work); diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index a2c05d2..e06c97f 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -682,7 +682,7 @@ struct cftype cgroup1_base_files[] = { }; /* Display information about each subsystem and each hierarchy */ -static int proc_cgroupstats_show(struct seq_file *m, void *v) +int proc_cgroupstats_show(struct seq_file *m, void *v) { struct cgroup_subsys *ss; int i; @@ -705,18 +705,6 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v) return 0; } -static int cgroupstats_open(struct inode *inode, struct file *file) -{ - return single_open(file, proc_cgroupstats_show, NULL); -} - -const struct file_operations proc_cgroupstats_operations = { - .open = cgroupstats_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - /** * cgroupstats_build - build and fill cgroupstats * @stats: cgroupstats to fill information into diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index a662bfc..077370b 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -54,6 +54,7 @@ #include <linux/proc_ns.h> #include <linux/nsproxy.h> #include <linux/file.h> +#include <linux/sched/cputime.h> #include <net/sock.h> #define CREATE_TRACE_POINTS @@ -61,6 +62,8 @@ #define CGROUP_FILE_NAME_MAX (MAX_CGROUP_TYPE_NAMELEN + \ MAX_CFTYPE_NAME + 2) +/* let's not notify more than 100 times per second */ +#define CGROUP_FILE_NOTIFY_MIN_INTV DIV_ROUND_UP(HZ, 100) /* * cgroup_mutex is the master lock. Any modification to cgroup or its @@ -142,14 +145,14 @@ static struct static_key_true *cgroup_subsys_on_dfl_key[] = { }; #undef SUBSYS -static DEFINE_PER_CPU(struct cgroup_cpu_stat, cgrp_dfl_root_cpu_stat); +static DEFINE_PER_CPU(struct cgroup_rstat_cpu, cgrp_dfl_root_rstat_cpu); /* * The default hierarchy, reserved for the subsystems that are otherwise * unattached - it never has more than a single cgroup, and all tasks are * part of that cgroup. */ -struct cgroup_root cgrp_dfl_root = { .cgrp.cpu_stat = &cgrp_dfl_root_cpu_stat }; +struct cgroup_root cgrp_dfl_root = { .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu }; EXPORT_SYMBOL_GPL(cgrp_dfl_root); /* @@ -1554,6 +1557,8 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) spin_lock_irq(&cgroup_file_kn_lock); cfile->kn = NULL; spin_unlock_irq(&cgroup_file_kn_lock); + + del_timer_sync(&cfile->notify_timer); } kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name)); @@ -1573,8 +1578,17 @@ static void css_clear_dir(struct cgroup_subsys_state *css) css->flags &= ~CSS_VISIBLE; - list_for_each_entry(cfts, &css->ss->cfts, node) + if (!css->ss) { + if (cgroup_on_dfl(cgrp)) + cfts = cgroup_base_files; + else + cfts = cgroup1_base_files; + cgroup_addrm_files(css, cgrp, cfts, false); + } else { + list_for_each_entry(cfts, &css->ss->cfts, node) + cgroup_addrm_files(css, cgrp, cfts, false); + } } /** @@ -1598,14 +1612,16 @@ static int css_populate_dir(struct cgroup_subsys_state *css) else cfts = cgroup1_base_files; - return cgroup_addrm_files(&cgrp->self, cgrp, cfts, true); - } - - list_for_each_entry(cfts, &css->ss->cfts, node) { - ret = cgroup_addrm_files(css, cgrp, cfts, true); - if (ret < 0) { - failed_cfts = cfts; - goto err; + ret = cgroup_addrm_files(&cgrp->self, cgrp, cfts, true); + if (ret < 0) + return ret; + } else { + list_for_each_entry(cfts, &css->ss->cfts, node) { + ret = cgroup_addrm_files(css, cgrp, cfts, true); + if (ret < 0) { + failed_cfts = cfts; + goto err; + } } } @@ -1782,13 +1798,6 @@ static void cgroup_enable_task_cg_lists(void) { struct task_struct *p, *g; - spin_lock_irq(&css_set_lock); - - if (use_task_css_set_links) - goto out_unlock; - - use_task_css_set_links = true; - /* * We need tasklist_lock because RCU is not safe against * while_each_thread(). Besides, a forking task that has passed @@ -1797,6 +1806,13 @@ static void cgroup_enable_task_cg_lists(void) * tasklist if we walk through it with RCU. */ read_lock(&tasklist_lock); + spin_lock_irq(&css_set_lock); + + if (use_task_css_set_links) + goto out_unlock; + + use_task_css_set_links = true; + do_each_thread(g, p) { WARN_ON_ONCE(!list_empty(&p->cg_list) || task_css_set(p) != &init_css_set); @@ -1824,9 +1840,9 @@ static void cgroup_enable_task_cg_lists(void) } spin_unlock(&p->sighand->siglock); } while_each_thread(g, p); - read_unlock(&tasklist_lock); out_unlock: spin_unlock_irq(&css_set_lock); + read_unlock(&tasklist_lock); } static void init_cgroup_housekeeping(struct cgroup *cgrp) @@ -1844,6 +1860,8 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) cgrp->dom_cgrp = cgrp; cgrp->max_descendants = INT_MAX; cgrp->max_depth = INT_MAX; + INIT_LIST_HEAD(&cgrp->rstat_css_list); + prev_cputime_init(&cgrp->prev_cputime); for_each_subsys(ss, ssid) INIT_LIST_HEAD(&cgrp->e_csets[ssid]); @@ -3381,7 +3399,7 @@ static int cpu_stat_show(struct seq_file *seq, void *v) struct cgroup __maybe_unused *cgrp = seq_css(seq)->cgroup; int ret = 0; - cgroup_stat_show_cputime(seq); + cgroup_base_stat_cputime_show(seq); #ifdef CONFIG_CGROUP_SCHED ret = cgroup_extra_stat_show(seq, cgrp, cpu_cgrp_id); #endif @@ -3521,6 +3539,12 @@ static int cgroup_kn_set_ugid(struct kernfs_node *kn) return kernfs_setattr(kn, &iattr); } +static void cgroup_file_notify_timer(struct timer_list *timer) +{ + cgroup_file_notify(container_of(timer, struct cgroup_file, + notify_timer)); +} + static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp, struct cftype *cft) { @@ -3547,6 +3571,8 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp, if (cft->file_offset) { struct cgroup_file *cfile = (void *)css + cft->file_offset; + timer_setup(&cfile->notify_timer, cgroup_file_notify_timer, 0); + spin_lock_irq(&cgroup_file_kn_lock); cfile->kn = kn; spin_unlock_irq(&cgroup_file_kn_lock); @@ -3796,8 +3822,17 @@ void cgroup_file_notify(struct cgroup_file *cfile) unsigned long flags; spin_lock_irqsave(&cgroup_file_kn_lock, flags); - if (cfile->kn) - kernfs_notify(cfile->kn); + if (cfile->kn) { + unsigned long last = cfile->notified_at; + unsigned long next = last + CGROUP_FILE_NOTIFY_MIN_INTV; + + if (time_in_range(jiffies, last, next)) { + timer_reduce(&cfile->notify_timer, next); + } else { + kernfs_notify(cfile->kn); + cfile->notified_at = jiffies; + } + } spin_unlock_irqrestore(&cgroup_file_kn_lock, flags); } @@ -4560,7 +4595,7 @@ static void css_free_rwork_fn(struct work_struct *work) cgroup_put(cgroup_parent(cgrp)); kernfs_put(cgrp->kn); if (cgroup_on_dfl(cgrp)) - cgroup_stat_exit(cgrp); + cgroup_rstat_exit(cgrp); kfree(cgrp); } else { /* @@ -4587,6 +4622,11 @@ static void css_release_work_fn(struct work_struct *work) if (ss) { /* css release path */ + if (!list_empty(&css->rstat_css_node)) { + cgroup_rstat_flush(cgrp); + list_del_rcu(&css->rstat_css_node); + } + cgroup_idr_replace(&ss->css_idr, NULL, css->id); if (ss->css_released) ss->css_released(css); @@ -4597,7 +4637,7 @@ static void css_release_work_fn(struct work_struct *work) trace_cgroup_release(cgrp); if (cgroup_on_dfl(cgrp)) - cgroup_stat_flush(cgrp); + cgroup_rstat_flush(cgrp); for (tcgrp = cgroup_parent(cgrp); tcgrp; tcgrp = cgroup_parent(tcgrp)) @@ -4648,6 +4688,7 @@ static void init_and_link_css(struct cgroup_subsys_state *css, css->id = -1; INIT_LIST_HEAD(&css->sibling); INIT_LIST_HEAD(&css->children); + INIT_LIST_HEAD(&css->rstat_css_node); css->serial_nr = css_serial_nr_next++; atomic_set(&css->online_cnt, 0); @@ -4656,6 +4697,9 @@ static void init_and_link_css(struct cgroup_subsys_state *css, css_get(css->parent); } + if (cgroup_on_dfl(cgrp) && ss->css_rstat_flush) + list_add_rcu(&css->rstat_css_node, &cgrp->rstat_css_list); + BUG_ON(cgroup_css(cgrp, ss)); } @@ -4757,6 +4801,7 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, err_list_del: list_del_rcu(&css->sibling); err_free_css: + list_del_rcu(&css->rstat_css_node); INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn); queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork); return ERR_PTR(err); @@ -4775,8 +4820,8 @@ static struct cgroup *cgroup_create(struct cgroup *parent) int ret; /* allocate the cgroup and its ID, 0 is reserved for the root */ - cgrp = kzalloc(sizeof(*cgrp) + - sizeof(cgrp->ancestor_ids[0]) * (level + 1), GFP_KERNEL); + cgrp = kzalloc(struct_size(cgrp, ancestor_ids, (level + 1)), + GFP_KERNEL); if (!cgrp) return ERR_PTR(-ENOMEM); @@ -4785,7 +4830,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent) goto out_free_cgrp; if (cgroup_on_dfl(parent)) { - ret = cgroup_stat_init(cgrp); + ret = cgroup_rstat_init(cgrp); if (ret) goto out_cancel_ref; } @@ -4850,7 +4895,7 @@ out_idr_free: cgroup_idr_remove(&root->cgroup_idr, cgrp->id); out_stat_exit: if (cgroup_on_dfl(parent)) - cgroup_stat_exit(cgrp); + cgroup_rstat_exit(cgrp); out_cancel_ref: percpu_ref_exit(&cgrp->self.refcnt); out_free_cgrp: @@ -5090,10 +5135,8 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) for_each_css(css, ssid, cgrp) kill_css(css); - /* - * Remove @cgrp directory along with the base files. @cgrp has an - * extra ref on its kn. - */ + /* clear and remove @cgrp dir, @cgrp has an extra ref on its kn */ + css_clear_dir(&cgrp->self); kernfs_remove(cgrp->kn); if (parent && cgroup_is_threaded(cgrp)) @@ -5245,7 +5288,7 @@ int __init cgroup_init(void) BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files)); BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files)); - cgroup_stat_boot(); + cgroup_rstat_boot(); /* * The latency of the synchronize_sched() is too high for cgroups, @@ -5335,7 +5378,7 @@ int __init cgroup_init(void) WARN_ON(sysfs_create_mount_point(fs_kobj, "cgroup")); WARN_ON(register_filesystem(&cgroup_fs_type)); WARN_ON(register_filesystem(&cgroup2_fs_type)); - WARN_ON(!proc_create("cgroups", 0, NULL, &proc_cgroupstats_operations)); + WARN_ON(!proc_create_single("cgroups", 0, NULL, proc_cgroupstats_show)); return 0; } diff --git a/kernel/cgroup/rdma.c b/kernel/cgroup/rdma.c index defad3c..d3bbb75 100644 --- a/kernel/cgroup/rdma.c +++ b/kernel/cgroup/rdma.c @@ -362,35 +362,32 @@ EXPORT_SYMBOL(rdmacg_unregister_device); static int parse_resource(char *c, int *intval) { substring_t argstr; - const char **table = &rdmacg_resource_names[0]; char *name, *value = c; size_t len; - int ret, i = 0; + int ret, i; name = strsep(&value, "="); if (!name || !value) return -EINVAL; - len = strlen(value); + i = match_string(rdmacg_resource_names, RDMACG_RESOURCE_MAX, name); + if (i < 0) + return i; - for (i = 0; i < RDMACG_RESOURCE_MAX; i++) { - if (strcmp(table[i], name)) - continue; + len = strlen(value); - argstr.from = value; - argstr.to = value + len; + argstr.from = value; + argstr.to = value + len; - ret = match_int(&argstr, intval); - if (ret >= 0) { - if (*intval < 0) - break; - return i; - } - if (strncmp(value, RDMACG_MAX_STR, len) == 0) { - *intval = S32_MAX; - return i; - } - break; + ret = match_int(&argstr, intval); + if (ret >= 0) { + if (*intval < 0) + return -EINVAL; + return i; + } + if (strncmp(value, RDMACG_MAX_STR, len) == 0) { + *intval = S32_MAX; + return i; } return -EINVAL; } diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c new file mode 100644 index 0000000..d503d1a --- /dev/null +++ b/kernel/cgroup/rstat.c @@ -0,0 +1,416 @@ +#include "cgroup-internal.h" + +#include <linux/sched/cputime.h> + +static DEFINE_SPINLOCK(cgroup_rstat_lock); +static DEFINE_PER_CPU(raw_spinlock_t, cgroup_rstat_cpu_lock); + +static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu); + +static struct cgroup_rstat_cpu *cgroup_rstat_cpu(struct cgroup *cgrp, int cpu) +{ + return per_cpu_ptr(cgrp->rstat_cpu, cpu); +} + +/** + * cgroup_rstat_updated - keep track of updated rstat_cpu + * @cgrp: target cgroup + * @cpu: cpu on which rstat_cpu was updated + * + * @cgrp's rstat_cpu on @cpu was updated. Put it on the parent's matching + * rstat_cpu->updated_children list. See the comment on top of + * cgroup_rstat_cpu definition for details. + */ +void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) +{ + raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu); + struct cgroup *parent; + unsigned long flags; + + /* nothing to do for root */ + if (!cgroup_parent(cgrp)) + return; + + /* + * Paired with the one in cgroup_rstat_cpu_pop_upated(). Either we + * see NULL updated_next or they see our updated stat. + */ + smp_mb(); + + /* + * Because @parent's updated_children is terminated with @parent + * instead of NULL, we can tell whether @cgrp is on the list by + * testing the next pointer for NULL. + */ + if (cgroup_rstat_cpu(cgrp, cpu)->updated_next) + return; + + raw_spin_lock_irqsave(cpu_lock, flags); + + /* put @cgrp and all ancestors on the corresponding updated lists */ + for (parent = cgroup_parent(cgrp); parent; + cgrp = parent, parent = cgroup_parent(cgrp)) { + struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); + struct cgroup_rstat_cpu *prstatc = cgroup_rstat_cpu(parent, cpu); + + /* + * Both additions and removals are bottom-up. If a cgroup + * is already in the tree, all ancestors are. + */ + if (rstatc->updated_next) + break; + + rstatc->updated_next = prstatc->updated_children; + prstatc->updated_children = cgrp; + } + + raw_spin_unlock_irqrestore(cpu_lock, flags); +} +EXPORT_SYMBOL_GPL(cgroup_rstat_updated); + +/** + * cgroup_rstat_cpu_pop_updated - iterate and dismantle rstat_cpu updated tree + * @pos: current position + * @root: root of the tree to traversal + * @cpu: target cpu + * + * Walks the udpated rstat_cpu tree on @cpu from @root. %NULL @pos starts + * the traversal and %NULL return indicates the end. During traversal, + * each returned cgroup is unlinked from the tree. Must be called with the + * matching cgroup_rstat_cpu_lock held. + * + * The only ordering guarantee is that, for a parent and a child pair + * covered by a given traversal, if a child is visited, its parent is + * guaranteed to be visited afterwards. + */ +static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos, + struct cgroup *root, int cpu) +{ + struct cgroup_rstat_cpu *rstatc; + struct cgroup *parent; + + if (pos == root) + return NULL; + + /* + * We're gonna walk down to the first leaf and visit/remove it. We + * can pick whatever unvisited node as the starting point. + */ + if (!pos) + pos = root; + else + pos = cgroup_parent(pos); + + /* walk down to the first leaf */ + while (true) { + rstatc = cgroup_rstat_cpu(pos, cpu); + if (rstatc->updated_children == pos) + break; + pos = rstatc->updated_children; + } + + /* + * Unlink @pos from the tree. As the updated_children list is + * singly linked, we have to walk it to find the removal point. + * However, due to the way we traverse, @pos will be the first + * child in most cases. The only exception is @root. + */ + parent = cgroup_parent(pos); + if (parent && rstatc->updated_next) { + struct cgroup_rstat_cpu *prstatc = cgroup_rstat_cpu(parent, cpu); + struct cgroup_rstat_cpu *nrstatc; + struct cgroup **nextp; + + nextp = &prstatc->updated_children; + while (true) { + nrstatc = cgroup_rstat_cpu(*nextp, cpu); + if (*nextp == pos) + break; + + WARN_ON_ONCE(*nextp == parent); + nextp = &nrstatc->updated_next; + } + + *nextp = rstatc->updated_next; + rstatc->updated_next = NULL; + + /* + * Paired with the one in cgroup_rstat_cpu_updated(). + * Either they see NULL updated_next or we see their + * updated stat. + */ + smp_mb(); + } + + return pos; +} + +/* see cgroup_rstat_flush() */ +static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) + __releases(&cgroup_rstat_lock) __acquires(&cgroup_rstat_lock) +{ + int cpu; + + lockdep_assert_held(&cgroup_rstat_lock); + + for_each_possible_cpu(cpu) { + raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock, + cpu); + struct cgroup *pos = NULL; + + raw_spin_lock(cpu_lock); + while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) { + struct cgroup_subsys_state *css; + + cgroup_base_stat_flush(pos, cpu); + + rcu_read_lock(); + list_for_each_entry_rcu(css, &pos->rstat_css_list, + rstat_css_node) + css->ss->css_rstat_flush(css, cpu); + rcu_read_unlock(); + } + raw_spin_unlock(cpu_lock); + + /* if @may_sleep, play nice and yield if necessary */ + if (may_sleep && (need_resched() || + spin_needbreak(&cgroup_rstat_lock))) { + spin_unlock_irq(&cgroup_rstat_lock); + if (!cond_resched()) + cpu_relax(); + spin_lock_irq(&cgroup_rstat_lock); + } + } +} + +/** + * cgroup_rstat_flush - flush stats in @cgrp's subtree + * @cgrp: target cgroup + * + * Collect all per-cpu stats in @cgrp's subtree into the global counters + * and propagate them upwards. After this function returns, all cgroups in + * the subtree have up-to-date ->stat. + * + * This also gets all cgroups in the subtree including @cgrp off the + * ->updated_children lists. + * + * This function may block. + */ +void cgroup_rstat_flush(struct cgroup *cgrp) +{ + might_sleep(); + + spin_lock_irq(&cgroup_rstat_lock); + cgroup_rstat_flush_locked(cgrp, true); + spin_unlock_irq(&cgroup_rstat_lock); +} + +/** + * cgroup_rstat_flush_irqsafe - irqsafe version of cgroup_rstat_flush() + * @cgrp: target cgroup + * + * This function can be called from any context. + */ +void cgroup_rstat_flush_irqsafe(struct cgroup *cgrp) +{ + unsigned long flags; + + spin_lock_irqsave(&cgroup_rstat_lock, flags); + cgroup_rstat_flush_locked(cgrp, false); + spin_unlock_irqrestore(&cgroup_rstat_lock, flags); +} + +/** + * cgroup_rstat_flush_begin - flush stats in @cgrp's subtree and hold + * @cgrp: target cgroup + * + * Flush stats in @cgrp's subtree and prevent further flushes. Must be + * paired with cgroup_rstat_flush_release(). + * + * This function may block. + */ +void cgroup_rstat_flush_hold(struct cgroup *cgrp) + __acquires(&cgroup_rstat_lock) +{ + might_sleep(); + spin_lock_irq(&cgroup_rstat_lock); + cgroup_rstat_flush_locked(cgrp, true); +} + +/** + * cgroup_rstat_flush_release - release cgroup_rstat_flush_hold() + */ +void cgroup_rstat_flush_release(void) + __releases(&cgroup_rstat_lock) +{ + spin_unlock_irq(&cgroup_rstat_lock); +} + +int cgroup_rstat_init(struct cgroup *cgrp) +{ + int cpu; + + /* the root cgrp has rstat_cpu preallocated */ + if (!cgrp->rstat_cpu) { + cgrp->rstat_cpu = alloc_percpu(struct cgroup_rstat_cpu); + if (!cgrp->rstat_cpu) + return -ENOMEM; + } + + /* ->updated_children list is self terminated */ + for_each_possible_cpu(cpu) { + struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); + + rstatc->updated_children = cgrp; + u64_stats_init(&rstatc->bsync); + } + + return 0; +} + +void cgroup_rstat_exit(struct cgroup *cgrp) +{ + int cpu; + + cgroup_rstat_flush(cgrp); + + /* sanity check */ + for_each_possible_cpu(cpu) { + struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); + + if (WARN_ON_ONCE(rstatc->updated_children != cgrp) || + WARN_ON_ONCE(rstatc->updated_next)) + return; + } + + free_percpu(cgrp->rstat_cpu); + cgrp->rstat_cpu = NULL; +} + +void __init cgroup_rstat_boot(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + raw_spin_lock_init(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); + + BUG_ON(cgroup_rstat_init(&cgrp_dfl_root.cgrp)); +} + +/* + * Functions for cgroup basic resource statistics implemented on top of + * rstat. + */ +static void cgroup_base_stat_accumulate(struct cgroup_base_stat *dst_bstat, + struct cgroup_base_stat *src_bstat) +{ + dst_bstat->cputime.utime += src_bstat->cputime.utime; + dst_bstat->cputime.stime += src_bstat->cputime.stime; + dst_bstat->cputime.sum_exec_runtime += src_bstat->cputime.sum_exec_runtime; +} + +static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) +{ + struct cgroup *parent = cgroup_parent(cgrp); + struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); + struct task_cputime *last_cputime = &rstatc->last_bstat.cputime; + struct task_cputime cputime; + struct cgroup_base_stat delta; + unsigned seq; + + /* fetch the current per-cpu values */ + do { + seq = __u64_stats_fetch_begin(&rstatc->bsync); + cputime = rstatc->bstat.cputime; + } while (__u64_stats_fetch_retry(&rstatc->bsync, seq)); + + /* calculate the delta to propgate */ + delta.cputime.utime = cputime.utime - last_cputime->utime; + delta.cputime.stime = cputime.stime - last_cputime->stime; + delta.cputime.sum_exec_runtime = cputime.sum_exec_runtime - + last_cputime->sum_exec_runtime; + *last_cputime = cputime; + + /* transfer the pending stat into delta */ + cgroup_base_stat_accumulate(&delta, &cgrp->pending_bstat); + memset(&cgrp->pending_bstat, 0, sizeof(cgrp->pending_bstat)); + + /* propagate delta into the global stat and the parent's pending */ + cgroup_base_stat_accumulate(&cgrp->bstat, &delta); + if (parent) + cgroup_base_stat_accumulate(&parent->pending_bstat, &delta); +} + +static struct cgroup_rstat_cpu * +cgroup_base_stat_cputime_account_begin(struct cgroup *cgrp) +{ + struct cgroup_rstat_cpu *rstatc; + + rstatc = get_cpu_ptr(cgrp->rstat_cpu); + u64_stats_update_begin(&rstatc->bsync); + return rstatc; +} + +static void cgroup_base_stat_cputime_account_end(struct cgroup *cgrp, + struct cgroup_rstat_cpu *rstatc) +{ + u64_stats_update_end(&rstatc->bsync); + cgroup_rstat_updated(cgrp, smp_processor_id()); + put_cpu_ptr(rstatc); +} + +void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec) +{ + struct cgroup_rstat_cpu *rstatc; + + rstatc = cgroup_base_stat_cputime_account_begin(cgrp); + rstatc->bstat.cputime.sum_exec_runtime += delta_exec; + cgroup_base_stat_cputime_account_end(cgrp, rstatc); +} + +void __cgroup_account_cputime_field(struct cgroup *cgrp, + enum cpu_usage_stat index, u64 delta_exec) +{ + struct cgroup_rstat_cpu *rstatc; + + rstatc = cgroup_base_stat_cputime_account_begin(cgrp); + + switch (index) { + case CPUTIME_USER: + case CPUTIME_NICE: + rstatc->bstat.cputime.utime += delta_exec; + break; + case CPUTIME_SYSTEM: + case CPUTIME_IRQ: + case CPUTIME_SOFTIRQ: + rstatc->bstat.cputime.stime += delta_exec; + break; + default: + break; + } + + cgroup_base_stat_cputime_account_end(cgrp, rstatc); +} + +void cgroup_base_stat_cputime_show(struct seq_file *seq) +{ + struct cgroup *cgrp = seq_css(seq)->cgroup; + u64 usage, utime, stime; + + if (!cgroup_parent(cgrp)) + return; + + cgroup_rstat_flush_hold(cgrp); + usage = cgrp->bstat.cputime.sum_exec_runtime; + cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime, &utime, &stime); + cgroup_rstat_flush_release(); + + do_div(usage, NSEC_PER_USEC); + do_div(utime, NSEC_PER_USEC); + do_div(stime, NSEC_PER_USEC); + + seq_printf(seq, "usage_usec %llu\n" + "user_usec %llu\n" + "system_usec %llu\n", + usage, utime, stime); +} diff --git a/kernel/cgroup/stat.c b/kernel/cgroup/stat.c deleted file mode 100644 index 1e111dd..0000000 --- a/kernel/cgroup/stat.c +++ /dev/null @@ -1,338 +0,0 @@ -#include "cgroup-internal.h" - -#include <linux/sched/cputime.h> - -static DEFINE_MUTEX(cgroup_stat_mutex); -static DEFINE_PER_CPU(raw_spinlock_t, cgroup_cpu_stat_lock); - -static struct cgroup_cpu_stat *cgroup_cpu_stat(struct cgroup *cgrp, int cpu) -{ - return per_cpu_ptr(cgrp->cpu_stat, cpu); -} - -/** - * cgroup_cpu_stat_updated - keep track of updated cpu_stat - * @cgrp: target cgroup - * @cpu: cpu on which cpu_stat was updated - * - * @cgrp's cpu_stat on @cpu was updated. Put it on the parent's matching - * cpu_stat->updated_children list. See the comment on top of - * cgroup_cpu_stat definition for details. - */ -static void cgroup_cpu_stat_updated(struct cgroup *cgrp, int cpu) -{ - raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_cpu_stat_lock, cpu); - struct cgroup *parent; - unsigned long flags; - - /* - * Speculative already-on-list test. This may race leading to - * temporary inaccuracies, which is fine. - * - * Because @parent's updated_children is terminated with @parent - * instead of NULL, we can tell whether @cgrp is on the list by - * testing the next pointer for NULL. - */ - if (cgroup_cpu_stat(cgrp, cpu)->updated_next) - return; - - raw_spin_lock_irqsave(cpu_lock, flags); - - /* put @cgrp and all ancestors on the corresponding updated lists */ - for (parent = cgroup_parent(cgrp); parent; - cgrp = parent, parent = cgroup_parent(cgrp)) { - struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu); - struct cgroup_cpu_stat *pcstat = cgroup_cpu_stat(parent, cpu); - - /* - * Both additions and removals are bottom-up. If a cgroup - * is already in the tree, all ancestors are. - */ - if (cstat->updated_next) - break; - - cstat->updated_next = pcstat->updated_children; - pcstat->updated_children = cgrp; - } - - raw_spin_unlock_irqrestore(cpu_lock, flags); -} - -/** - * cgroup_cpu_stat_pop_updated - iterate and dismantle cpu_stat updated tree - * @pos: current position - * @root: root of the tree to traversal - * @cpu: target cpu - * - * Walks the udpated cpu_stat tree on @cpu from @root. %NULL @pos starts - * the traversal and %NULL return indicates the end. During traversal, - * each returned cgroup is unlinked from the tree. Must be called with the - * matching cgroup_cpu_stat_lock held. - * - * The only ordering guarantee is that, for a parent and a child pair - * covered by a given traversal, if a child is visited, its parent is - * guaranteed to be visited afterwards. - */ -static struct cgroup *cgroup_cpu_stat_pop_updated(struct cgroup *pos, - struct cgroup *root, int cpu) -{ - struct cgroup_cpu_stat *cstat; - struct cgroup *parent; - - if (pos == root) - return NULL; - - /* - * We're gonna walk down to the first leaf and visit/remove it. We - * can pick whatever unvisited node as the starting point. - */ - if (!pos) - pos = root; - else - pos = cgroup_parent(pos); - - /* walk down to the first leaf */ - while (true) { - cstat = cgroup_cpu_stat(pos, cpu); - if (cstat->updated_children == pos) - break; - pos = cstat->updated_children; - } - - /* - * Unlink @pos from the tree. As the updated_children list is - * singly linked, we have to walk it to find the removal point. - * However, due to the way we traverse, @pos will be the first - * child in most cases. The only exception is @root. - */ - parent = cgroup_parent(pos); - if (parent && cstat->updated_next) { - struct cgroup_cpu_stat *pcstat = cgroup_cpu_stat(parent, cpu); - struct cgroup_cpu_stat *ncstat; - struct cgroup **nextp; - - nextp = &pcstat->updated_children; - while (true) { - ncstat = cgroup_cpu_stat(*nextp, cpu); - if (*nextp == pos) - break; - - WARN_ON_ONCE(*nextp == parent); - nextp = &ncstat->updated_next; - } - - *nextp = cstat->updated_next; - cstat->updated_next = NULL; - } - - return pos; -} - -static void cgroup_stat_accumulate(struct cgroup_stat *dst_stat, - struct cgroup_stat *src_stat) -{ - dst_stat->cputime.utime += src_stat->cputime.utime; - dst_stat->cputime.stime += src_stat->cputime.stime; - dst_stat->cputime.sum_exec_runtime += src_stat->cputime.sum_exec_runtime; -} - -static void cgroup_cpu_stat_flush_one(struct cgroup *cgrp, int cpu) -{ - struct cgroup *parent = cgroup_parent(cgrp); - struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu); - struct task_cputime *last_cputime = &cstat->last_cputime; - struct task_cputime cputime; - struct cgroup_stat delta; - unsigned seq; - - lockdep_assert_held(&cgroup_stat_mutex); - - /* fetch the current per-cpu values */ - do { - seq = __u64_stats_fetch_begin(&cstat->sync); - cputime = cstat->cputime; - } while (__u64_stats_fetch_retry(&cstat->sync, seq)); - - /* accumulate the deltas to propgate */ - delta.cputime.utime = cputime.utime - last_cputime->utime; - delta.cputime.stime = cputime.stime - last_cputime->stime; - delta.cputime.sum_exec_runtime = cputime.sum_exec_runtime - - last_cputime->sum_exec_runtime; - *last_cputime = cputime; - - /* transfer the pending stat into delta */ - cgroup_stat_accumulate(&delta, &cgrp->pending_stat); - memset(&cgrp->pending_stat, 0, sizeof(cgrp->pending_stat)); - - /* propagate delta into the global stat and the parent's pending */ - cgroup_stat_accumulate(&cgrp->stat, &delta); - if (parent) - cgroup_stat_accumulate(&parent->pending_stat, &delta); -} - -/* see cgroup_stat_flush() */ -static void cgroup_stat_flush_locked(struct cgroup *cgrp) -{ - int cpu; - - lockdep_assert_held(&cgroup_stat_mutex); - - for_each_possible_cpu(cpu) { - raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_cpu_stat_lock, cpu); - struct cgroup *pos = NULL; - - raw_spin_lock_irq(cpu_lock); - while ((pos = cgroup_cpu_stat_pop_updated(pos, cgrp, cpu))) - cgroup_cpu_stat_flush_one(pos, cpu); - raw_spin_unlock_irq(cpu_lock); - } -} - -/** - * cgroup_stat_flush - flush stats in @cgrp's subtree - * @cgrp: target cgroup - * - * Collect all per-cpu stats in @cgrp's subtree into the global counters - * and propagate them upwards. After this function returns, all cgroups in - * the subtree have up-to-date ->stat. - * - * This also gets all cgroups in the subtree including @cgrp off the - * ->updated_children lists. - */ -void cgroup_stat_flush(struct cgroup *cgrp) -{ - mutex_lock(&cgroup_stat_mutex); - cgroup_stat_flush_locked(cgrp); - mutex_unlock(&cgroup_stat_mutex); -} - -static struct cgroup_cpu_stat *cgroup_cpu_stat_account_begin(struct cgroup *cgrp) -{ - struct cgroup_cpu_stat *cstat; - - cstat = get_cpu_ptr(cgrp->cpu_stat); - u64_stats_update_begin(&cstat->sync); - return cstat; -} - -static void cgroup_cpu_stat_account_end(struct cgroup *cgrp, - struct cgroup_cpu_stat *cstat) -{ - u64_stats_update_end(&cstat->sync); - cgroup_cpu_stat_updated(cgrp, smp_processor_id()); - put_cpu_ptr(cstat); -} - -void __cgroup_account_cputime(struct cgroup *cgrp, u64 delta_exec) -{ - struct cgroup_cpu_stat *cstat; - - cstat = cgroup_cpu_stat_account_begin(cgrp); - cstat->cputime.sum_exec_runtime += delta_exec; - cgroup_cpu_stat_account_end(cgrp, cstat); -} - -void __cgroup_account_cputime_field(struct cgroup *cgrp, - enum cpu_usage_stat index, u64 delta_exec) -{ - struct cgroup_cpu_stat *cstat; - - cstat = cgroup_cpu_stat_account_begin(cgrp); - - switch (index) { - case CPUTIME_USER: - case CPUTIME_NICE: - cstat->cputime.utime += delta_exec; - break; - case CPUTIME_SYSTEM: - case CPUTIME_IRQ: - case CPUTIME_SOFTIRQ: - cstat->cputime.stime += delta_exec; - break; - default: - break; - } - - cgroup_cpu_stat_account_end(cgrp, cstat); -} - -void cgroup_stat_show_cputime(struct seq_file *seq) -{ - struct cgroup *cgrp = seq_css(seq)->cgroup; - u64 usage, utime, stime; - - if (!cgroup_parent(cgrp)) - return; - - mutex_lock(&cgroup_stat_mutex); - - cgroup_stat_flush_locked(cgrp); - - usage = cgrp->stat.cputime.sum_exec_runtime; - cputime_adjust(&cgrp->stat.cputime, &cgrp->stat.prev_cputime, - &utime, &stime); - - mutex_unlock(&cgroup_stat_mutex); - - do_div(usage, NSEC_PER_USEC); - do_div(utime, NSEC_PER_USEC); - do_div(stime, NSEC_PER_USEC); - - seq_printf(seq, "usage_usec %llu\n" - "user_usec %llu\n" - "system_usec %llu\n", - usage, utime, stime); -} - -int cgroup_stat_init(struct cgroup *cgrp) -{ - int cpu; - - /* the root cgrp has cpu_stat preallocated */ - if (!cgrp->cpu_stat) { - cgrp->cpu_stat = alloc_percpu(struct cgroup_cpu_stat); - if (!cgrp->cpu_stat) - return -ENOMEM; - } - - /* ->updated_children list is self terminated */ - for_each_possible_cpu(cpu) { - struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu); - - cstat->updated_children = cgrp; - u64_stats_init(&cstat->sync); - } - - prev_cputime_init(&cgrp->stat.prev_cputime); - - return 0; -} - -void cgroup_stat_exit(struct cgroup *cgrp) -{ - int cpu; - - cgroup_stat_flush(cgrp); - - /* sanity check */ - for_each_possible_cpu(cpu) { - struct cgroup_cpu_stat *cstat = cgroup_cpu_stat(cgrp, cpu); - - if (WARN_ON_ONCE(cstat->updated_children != cgrp) || - WARN_ON_ONCE(cstat->updated_next)) - return; - } - - free_percpu(cgrp->cpu_stat); - cgrp->cpu_stat = NULL; -} - -void __init cgroup_stat_boot(void) -{ - int cpu; - - for_each_possible_cpu(cpu) - raw_spin_lock_init(per_cpu_ptr(&cgroup_cpu_stat_lock, cpu)); - - BUG_ON(cgroup_stat_init(&cgrp_dfl_root.cgrp)); -} |
