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| author | Yafang Shao <laoar.shao@gmail.com> | 2020-03-16 21:28:05 -0400 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-03-20 13:06:19 +0100 |
| commit | 1066d1b6974e095d5a6c472ad9180a957b496cd6 (patch) | |
| tree | 32f387de4a544bdc0772949e6ffe9464ea229bc0 /kernel | |
| parent | a0fe6ba69059266ba70ed5d3c4ac80713f6ffde7 (diff) | |
| download | linux-1066d1b6974e095d5a6c472ad9180a957b496cd6.tar.gz linux-1066d1b6974e095d5a6c472ad9180a957b496cd6.tar.bz2 linux-1066d1b6974e095d5a6c472ad9180a957b496cd6.zip | |
psi: Move PF_MEMSTALL out of task->flags
The task->flags is a 32-bits flag, in which 31 bits have already been
consumed. So it is hardly to introduce other new per process flag.
Currently there're still enough spaces in the bit-field section of
task_struct, so we can define the memstall state as a single bit in
task_struct instead.
This patch also removes an out-of-date comment pointed by Matthew.
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/1584408485-1921-1-git-send-email-laoar.shao@gmail.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/psi.c | 12 | ||||
| -rw-r--r-- | kernel/sched/stats.h | 10 |
2 files changed, 11 insertions, 11 deletions
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 955a124bae81..8f45cdb6463b 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -865,17 +865,17 @@ void psi_memstall_enter(unsigned long *flags) if (static_branch_likely(&psi_disabled)) return; - *flags = current->flags & PF_MEMSTALL; + *flags = current->in_memstall; if (*flags) return; /* - * PF_MEMSTALL setting & accounting needs to be atomic wrt + * in_memstall setting & accounting needs to be atomic wrt * changes to the task's scheduling state, otherwise we can * race with CPU migration. */ rq = this_rq_lock_irq(&rf); - current->flags |= PF_MEMSTALL; + current->in_memstall = 1; psi_task_change(current, 0, TSK_MEMSTALL); rq_unlock_irq(rq, &rf); @@ -898,13 +898,13 @@ void psi_memstall_leave(unsigned long *flags) if (*flags) return; /* - * PF_MEMSTALL clearing & accounting needs to be atomic wrt + * in_memstall clearing & accounting needs to be atomic wrt * changes to the task's scheduling state, otherwise we could * race with CPU migration. */ rq = this_rq_lock_irq(&rf); - current->flags &= ~PF_MEMSTALL; + current->in_memstall = 0; psi_task_change(current, TSK_MEMSTALL, 0); rq_unlock_irq(rq, &rf); @@ -970,7 +970,7 @@ void cgroup_move_task(struct task_struct *task, struct css_set *to) } else if (task->in_iowait) task_flags = TSK_IOWAIT; - if (task->flags & PF_MEMSTALL) + if (task->in_memstall) task_flags |= TSK_MEMSTALL; if (task_flags) diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index 1339f5bfe513..33d0daf83842 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -70,7 +70,7 @@ static inline void psi_enqueue(struct task_struct *p, bool wakeup) return; if (!wakeup || p->sched_psi_wake_requeue) { - if (p->flags & PF_MEMSTALL) + if (p->in_memstall) set |= TSK_MEMSTALL; if (p->sched_psi_wake_requeue) p->sched_psi_wake_requeue = 0; @@ -90,7 +90,7 @@ static inline void psi_dequeue(struct task_struct *p, bool sleep) return; if (!sleep) { - if (p->flags & PF_MEMSTALL) + if (p->in_memstall) clear |= TSK_MEMSTALL; } else { /* @@ -117,14 +117,14 @@ 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->flags & PF_MEMSTALL))) { + if (unlikely(p->in_iowait || p->in_memstall)) { struct rq_flags rf; struct rq *rq; int clear = 0; if (p->in_iowait) clear |= TSK_IOWAIT; - if (p->flags & PF_MEMSTALL) + if (p->in_memstall) clear |= TSK_MEMSTALL; rq = __task_rq_lock(p, &rf); @@ -149,7 +149,7 @@ static inline void psi_task_tick(struct rq *rq) if (static_branch_likely(&psi_disabled)) return; - if (unlikely(rq->curr->flags & PF_MEMSTALL)) + if (unlikely(rq->curr->in_memstall)) psi_memstall_tick(rq->curr, cpu_of(rq)); } #else /* CONFIG_PSI */ |