diff options
| author | Roman Gushchin <guro@fb.com> | 2021-05-10 14:39:46 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2021-05-10 21:31:03 -0400 |
| commit | f4f809f66b7545b89bff4b132cdb37adc2d2c157 (patch) | |
| tree | a2af60079b8afcd3618db7fe87c580e3b2329ec2 | |
| parent | 85e3b86ed0b7e366b6e50da1ff2511c8758616c7 (diff) | |
cgroup: inline cgroup_task_freeze()
After the introduction of the cgroup.kill there is only one call site
of cgroup_task_freeze() left: cgroup_exit(). cgroup_task_freeze() is
currently taking rcu_read_lock() to read task's cgroup flags, but
because it's always called with css_set_lock locked, the rcu protection
is excessive.
Simplify the code by inlining cgroup_task_freeze().
v2: fix build
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | include/linux/cgroup.h | 18 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 3 |
2 files changed, 2 insertions, 19 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 4f2f79de083e..a72764287cb5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -906,20 +906,6 @@ void cgroup_freeze(struct cgroup *cgrp, bool freeze); void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src, struct cgroup *dst); -static inline bool cgroup_task_freeze(struct task_struct *task) -{ - bool ret; - - if (task->flags & PF_KTHREAD) - return false; - - rcu_read_lock(); - ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags); - rcu_read_unlock(); - - return ret; -} - static inline bool cgroup_task_frozen(struct task_struct *task) { return task->frozen; @@ -929,10 +915,6 @@ static inline bool cgroup_task_frozen(struct task_struct *task) static inline void cgroup_enter_frozen(void) { } static inline void cgroup_leave_frozen(bool always_leave) { } -static inline bool cgroup_task_freeze(struct task_struct *task) -{ - return false; -} static inline bool cgroup_task_frozen(struct task_struct *task) { return false; diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index e640fc78d731..8e0d7092afbb 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -6267,7 +6267,8 @@ void cgroup_exit(struct task_struct *tsk) cset->nr_tasks--; WARN_ON_ONCE(cgroup_task_frozen(tsk)); - if (unlikely(cgroup_task_freeze(tsk))) + if (unlikely(!(tsk->flags & PF_KTHREAD) && + test_bit(CGRP_FREEZE, &task_dfl_cgroup(tsk)->flags))) cgroup_update_frozen(task_dfl_cgroup(tsk)); spin_unlock_irq(&css_set_lock); |