Re: [PATCH v2 1/1] psi: stop relying on timer_pending for poll_work rescheduling
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-07-01 16:13:37
Also in:
linux-mediatek, lkml
On Thu, Jul 01, 2021 at 09:09:25AM -0700, Suren Baghdasaryan wrote:
On Thu, Jul 1, 2021 at 1:59 AM Peter Zijlstra [off-list ref] wrote:quoted
On Wed, Jun 30, 2021 at 01:51:51PM -0700, Suren Baghdasaryan wrote:quoted
+ /* cmpxchg should be called even when !force to set poll_scheduled */ + if (atomic_cmpxchg(&group->poll_scheduled, 0, 1) && !force) return;Why is that a cmpxchg() ?We want to set poll_scheduled and proceed with rescheduling the timer unless it's already scheduled, so cmpxchg helps us to make that decision atomically. Or did I misunderstand your question?
What's wrong with: atomic_xchg(&group->poll_scheduled, 1) ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel