Messages in this thread Patch in this message | | | Date | Wed, 4 Oct 2023 11:39:53 +0200 | From | Ingo Molnar <> | Subject | [PATCH] sched/core: Update stale comment in try_to_wake_up() |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Oct 04, 2023 at 11:31:26AM +0200, Ingo Molnar wrote: > > > > * Zhang Qiao <zhangqiao22@huawei.com> wrote: > > > > > Since commit 9b3c4ab3045e ("sched,rcu: Rework > > > try_invoke_on_locked_down_task()") renamed > > > try_invoke_on_locked_down_task() to task_call_func(). > > > Now, update some comment about it. > > > > > > Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com> > > > --- > > > kernel/sched/core.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > > > index 0d18c3969f90..540ac33ddb80 100644 > > > --- a/kernel/sched/core.c > > > +++ b/kernel/sched/core.c > > > @@ -4186,7 +4186,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) > > > * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in > > > * __schedule(). See the comment for smp_mb__after_spinlock(). > > > * > > > - * A similar smb_rmb() lives in try_invoke_on_locked_down_task(). > > > + * A similar smb_rmb() lives in task_call_func(). > > > > Except the matching smp_rmb() doesn't live in task_call_func() anymore, so > > you now turned a stale comment into a misleading one ... > > It moved, *again*, it's now in __task_needs_rq_lock() :-)
Yeah, I know, see:
bdf85bec2b1e ("sched/core: Update stale comment in try_to_wake_up()")
Thanks,
Ingo
====================> From: Ingo Molnar <mingo@kernel.org> Date: Wed, 4 Oct 2023 11:33:36 +0200 Subject: [PATCH] sched/core: Update stale comment in try_to_wake_up()
The following commit:
9b3c4ab3045e ("sched,rcu: Rework try_invoke_on_locked_down_task()")
... renamed try_invoke_on_locked_down_task() to task_call_func(), but forgot to update the comment in try_to_wake_up().
But it turns out that the smp_rmb() doesn't live in task_call_func() either, it was moved to __task_needs_rq_lock() in:
91dabf33ae5d ("sched: Fix race in task_call_func()")
Fix that now.
Also fix the s/smb/smp typo while at it.
Reported-by: Zhang Qiao <zhangqiao22@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230731085759.11443-1-zhangqiao22@huawei.com --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 65e10ac34660..f5783cb16791 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4237,7 +4237,7 @@ int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in * __schedule(). See the comment for smp_mb__after_spinlock(). * - * A similar smb_rmb() lives in try_invoke_on_locked_down_task(). + * A similar smp_rmb() lives in __task_needs_rq_lock(). */ smp_rmb(); if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags))
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