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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/sched/psi.c | |
| parent | MAINTAINERS: Add maintenance information for psi (diff) | |
| download | linux-dev-1066d1b6974e095d5a6c472ad9180a957b496cd6.tar.xz linux-dev-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This patch also removes an out-of-date comment pointed by Matthew.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 '')
| -rw-r--r-- | kernel/sched/psi.c | 12 |
1 files changed, 6 insertions, 6 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) |