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| author | Chengming Zhou <zhouchengming@bytedance.com> | 2022-09-26 11:19:31 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-10-30 12:12:15 +0300 |
| commit | 52b33d87b9197c51e8ffdc61873739d90dd0a16f (patch) | |
| tree | 392b655b87d75cce109258c3adc5f8157dea366b /kernel/sched | |
| parent | 710ffe671e014d5ccbcff225130a178b088ef090 (diff) | |
| download | linux-52b33d87b9197c51e8ffdc61873739d90dd0a16f.tar.xz | |
sched/psi: Use task->psi_flags to clear in CPU migration
The commit d583d360a620 ("psi: Fix psi state corruption when schedule()
races with cgroup move") fixed a race problem by making cgroup_move_task()
use task->psi_flags instead of looking at the scheduler state.
We can extend task->psi_flags usage to CPU migration, which should be
a minor optimization for performance and code simplicity.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220926081931.45420-1-zhouchengming@bytedance.com
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 2 | ||||
| -rw-r--r-- | kernel/sched/stats.h | 22 |
2 files changed, 5 insertions, 19 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 87c9cdf37a26..07ac08caf019 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2053,7 +2053,7 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) if (!(flags & ENQUEUE_RESTORE)) { sched_info_enqueue(rq, p); - psi_enqueue(p, flags & ENQUEUE_WAKEUP); + psi_enqueue(p, (flags & ENQUEUE_WAKEUP) && !(flags & ENQUEUE_MIGRATED)); } uclamp_rq_inc(rq, p); diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index 84a188913cc9..38f3698f5e5b 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -128,11 +128,9 @@ static inline void psi_enqueue(struct task_struct *p, bool wakeup) if (p->in_memstall) set |= TSK_MEMSTALL_RUNNING; - if (!wakeup || p->sched_psi_wake_requeue) { + if (!wakeup) { if (p->in_memstall) set |= TSK_MEMSTALL; - if (p->sched_psi_wake_requeue) - p->sched_psi_wake_requeue = 0; } else { if (p->in_iowait) clear |= TSK_IOWAIT; @@ -143,8 +141,6 @@ static inline void psi_enqueue(struct task_struct *p, bool wakeup) static inline void psi_dequeue(struct task_struct *p, bool sleep) { - int clear = TSK_RUNNING; - if (static_branch_likely(&psi_disabled)) return; @@ -157,10 +153,7 @@ static inline void psi_dequeue(struct task_struct *p, bool sleep) if (sleep) return; - if (p->in_memstall) - clear |= (TSK_MEMSTALL | TSK_MEMSTALL_RUNNING); - - psi_task_change(p, clear, 0); + psi_task_change(p, p->psi_flags, 0); } static inline void psi_ttwu_dequeue(struct task_struct *p) @@ -172,19 +165,12 @@ static inline void psi_ttwu_dequeue(struct task_struct *p) * deregister its sleep-persistent psi states from the old * queue, and let psi_enqueue() know it has to requeue. */ - if (unlikely(p->in_iowait || p->in_memstall)) { + if (unlikely(p->psi_flags)) { struct rq_flags rf; struct rq *rq; - int clear = 0; - - if (p->in_iowait) - clear |= TSK_IOWAIT; - if (p->in_memstall) - clear |= TSK_MEMSTALL; rq = __task_rq_lock(p, &rf); - psi_task_change(p, clear, 0); - p->sched_psi_wake_requeue = 1; + psi_task_change(p, p->psi_flags, 0); __task_rq_unlock(rq, &rf); } } |