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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 15:48:36 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 15:48:36 -0800 |
commit | a312a8cc3c7fe96f5e54e69c676f5bd12995f44e (patch) | |
tree | 29e44c7ab6c59dd841bc217be0796b4cf26a7f30 /kernel/cgroup | |
parent | bf57ae2165bad1cb273095a5c09708ab503cd874 (diff) | |
parent | 674b745e22b3caae48ad20422795eefd3f832a7b (diff) | |
download | linux-stable-a312a8cc3c7fe96f5e54e69c676f5bd12995f44e.tar.gz linux-stable-a312a8cc3c7fe96f5e54e69c676f5bd12995f44e.tar.bz2 linux-stable-a312a8cc3c7fe96f5e54e69c676f5bd12995f44e.zip |
Merge tag 'cgroup-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
"Nothing too interesting:
- Add CONFIG_DEBUG_GROUP_REF which makes cgroup refcnt operations
kprobable
- A couple cpuset optimizations
- Other misc changes including doc and test updates"
* tag 'cgroup-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: remove rcu_read_lock()/rcu_read_unlock() in critical section of spin_lock_irq()
cgroup/cpuset: Improve cpuset_css_alloc() description
kselftest/cgroup: Add cleanup() to test_cpuset_prs.sh
cgroup/cpuset: Optimize cpuset_attach() on v2
cgroup/cpuset: Skip spread flags update on v2
kselftest/cgroup: Fix gathering number of CPUs
cgroup: cgroup refcnt functions should be exported when CONFIG_DEBUG_CGROUP_REF
cgroup: Implement DEBUG_CGROUP_REF
Diffstat (limited to 'kernel/cgroup')
-rw-r--r-- | kernel/cgroup/cgroup.c | 8 | ||||
-rw-r--r-- | kernel/cgroup/cpuset.c | 48 |
2 files changed, 45 insertions, 11 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 2319946715e0..15cc26513596 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -248,6 +248,12 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css, struct cgroup *cgrp, struct cftype cfts[], bool is_add); +#ifdef CONFIG_DEBUG_CGROUP_REF +#define CGROUP_REF_FN_ATTRS noinline +#define CGROUP_REF_EXPORT(fn) EXPORT_SYMBOL_GPL(fn); +#include <linux/cgroup_refcnt.h> +#endif + /** * cgroup_ssid_enabled - cgroup subsys enabled test by subsys ID * @ssid: subsys ID of interest @@ -2860,14 +2866,12 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup, * take an rcu_read_lock. */ spin_lock_irq(&css_set_lock); - rcu_read_lock(); task = leader; do { cgroup_migrate_add_task(task, mgctx); if (!threadgroup) break; } while_each_thread(leader, task); - rcu_read_unlock(); spin_unlock_irq(&css_set_lock); return cgroup_migrate_execute(mgctx); diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index b474289c15b8..589827ccda8b 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -550,11 +550,15 @@ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask) /* * update task's spread flag if cpuset's page/slab spread flag is set * - * Call with callback_lock or cpuset_rwsem held. + * Call with callback_lock or cpuset_rwsem held. The check can be skipped + * if on default hierarchy. */ -static void cpuset_update_task_spread_flag(struct cpuset *cs, +static void cpuset_update_task_spread_flags(struct cpuset *cs, struct task_struct *tsk) { + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) + return; + if (is_spread_page(cs)) task_set_spread_page(tsk); else @@ -2153,7 +2157,7 @@ static void update_tasks_flags(struct cpuset *cs) css_task_iter_start(&cs->css, 0, &it); while ((task = css_task_iter_next(&it))) - cpuset_update_task_spread_flag(cs, task); + cpuset_update_task_spread_flags(cs, task); css_task_iter_end(&it); } @@ -2509,12 +2513,28 @@ static void cpuset_attach(struct cgroup_taskset *tset) struct cgroup_subsys_state *css; struct cpuset *cs; struct cpuset *oldcs = cpuset_attach_old_cs; + bool cpus_updated, mems_updated; cgroup_taskset_first(tset, &css); cs = css_cs(css); lockdep_assert_cpus_held(); /* see cgroup_attach_lock() */ percpu_down_write(&cpuset_rwsem); + cpus_updated = !cpumask_equal(cs->effective_cpus, + oldcs->effective_cpus); + mems_updated = !nodes_equal(cs->effective_mems, oldcs->effective_mems); + + /* + * In the default hierarchy, enabling cpuset in the child cgroups + * will trigger a number of cpuset_attach() calls with no change + * in effective cpus and mems. In that case, we can optimize out + * by skipping the task iteration and update. + */ + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) && + !cpus_updated && !mems_updated) { + cpuset_attach_nodemask_to = cs->effective_mems; + goto out; + } guarantee_online_mems(cs, &cpuset_attach_nodemask_to); @@ -2530,14 +2550,19 @@ static void cpuset_attach(struct cgroup_taskset *tset) WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach)); cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to); - cpuset_update_task_spread_flag(cs, task); + cpuset_update_task_spread_flags(cs, task); } /* * Change mm for all threadgroup leaders. This is expensive and may - * sleep and should be moved outside migration path proper. + * sleep and should be moved outside migration path proper. Skip it + * if there is no change in effective_mems and CS_MEMORY_MIGRATE is + * not set. */ cpuset_attach_nodemask_to = cs->effective_mems; + if (!is_memory_migrate(cs) && !mems_updated) + goto out; + cgroup_taskset_for_each_leader(leader, css, tset) { struct mm_struct *mm = get_task_mm(leader); @@ -2560,6 +2585,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) } } +out: cs->old_mems_allowed = cpuset_attach_nodemask_to; cs->attach_in_progress--; @@ -3046,11 +3072,15 @@ static struct cftype dfl_files[] = { }; -/* - * cpuset_css_alloc - allocate a cpuset css - * cgrp: control group that the new cpuset will be part of +/** + * cpuset_css_alloc - Allocate a cpuset css + * @parent_css: Parent css of the control group that the new cpuset will be + * part of + * Return: cpuset css on success, -ENOMEM on failure. + * + * Allocate and initialize a new cpuset css, for non-NULL @parent_css, return + * top cpuset css otherwise. */ - static struct cgroup_subsys_state * cpuset_css_alloc(struct cgroup_subsys_state *parent_css) { |