Messages in this thread | | | From | "Song Bao Hua (Barry Song)" <> | Subject | RE: [PATCH] sched/fair: don't use waker's cpu if the waker of sync wake-up is interrupt | Date | Tue, 27 Apr 2021 06:05:09 +0000 |
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> -----Original Message----- > From: Mike Galbraith [mailto:efault@gmx.de] > Sent: Tuesday, April 27, 2021 5:55 PM > To: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>; > vincent.guittot@linaro.org; mingo@redhat.com; peterz@infradead.org; > dietmar.eggemann@arm.com; rostedt@goodmis.org; bsegall@google.com; > mgorman@suse.de > Cc: valentin.schneider@arm.com; juri.lelli@redhat.com; bristot@redhat.com; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; xuwei (O) > <xuwei5@huawei.com>; Zengtao (B) <prime.zeng@hisilicon.com>; > guodong.xu@linaro.org; yangyicong <yangyicong@huawei.com>; Liguozhu (Kenneth) > <liguozhu@hisilicon.com>; linuxarm@openeuler.org; wanghuiqiang > <wanghuiqiang@huawei.com>; xieyongjia (A) <xieyongjia1@huawei.com> > Subject: Re: [PATCH] sched/fair: don't use waker's cpu if the waker of sync > wake-up is interrupt > > On Tue, 2021-04-27 at 04:44 +0000, Song Bao Hua (Barry Song) wrote: > > > > > > I agree sync hint might have been overused by other kernel subsystem. > > But this patch will at least fix a case: sync waker is interrupt, > > in this case, the existing task has nothing to do with waker and wakee, > > so this case should be excluded from wake_affine_idle(). > > I long ago tried filtering interrupt wakeups, and met some surprises. > Wakeup twiddling always managing to end up being a rob Peter to pay > Paul operation despite our best efforts, here's hoping that your pile > of stolen cycles is small enough to escape performance bot notice :)
Would you like to share the link you did before to filter interrupt wakeups?
The wake up path has hundreds of lines of code, so I don't expect that reading preempt_count will cause visible performance losses to bot. But who knows :-)
> > -Mike
Thanks Barry
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