From: Mel Gorman <mgorman@suse.de>
To: Hillf Danton <hdanton@sina.com>
Cc: Alexander Fomichev <fomichev.ru@gmail.com>,
linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
linux@yadro.com, Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC] Scheduler: DMA Engine regression because of sched/fair changes
Date: Tue, 18 Jan 2022 10:05:54 +0000 [thread overview]
Message-ID: <20220118100553.GR3301@suse.de> (raw)
In-Reply-To: <20220118020448.2399-1-hdanton@sina.com>
On Tue, Jan 18, 2022 at 10:04:48AM +0800, Hillf Danton wrote:
> > > > 5) What DMA Engine enabled drivers (and dmatest) should use as design
> > > > pattern to conform migration/cache behavior? Does scheduler optimisation
> > > > conflict to DMA Engine performance in general?
> > > >
> > >
> > > I'm not familiar with DMA engine drivers but if they use wake_up
> > > interfaces then passing WF_SYNC or calling the wake_up_*_sync helpers
> > > may force the migration.
> > >
> >
> > Thanks for the advice. I'll try to check if this is a solution.
>
> Check if cold cache provides some room for selecting CPU.
>
> Only for thoughts now.
>
That will still favour migrating tasks between CPUs that share LLC cache
at the expense of losing some higher level caches and cpufreq state
(depending on the CPUfreq governor).
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2022-01-18 10:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-12 15:26 [RFC] Scheduler: DMA Engine regression because of sched/fair changes Alexander Fomichev
2022-01-12 17:05 ` Mel Gorman
2022-01-17 8:19 ` Alexander Fomichev
2022-01-17 10:27 ` Mel Gorman
2022-01-17 17:44 ` Alexander Fomichev
[not found] ` <20220118020448.2399-1-hdanton@sina.com>
2022-01-18 10:05 ` Mel Gorman [this message]
2022-01-19 12:55 ` Alexander Fomichev
[not found] ` <20220121101217.2849-1-hdanton@sina.com>
2022-01-21 13:46 ` Alexander Fomichev
[not found] ` <20220122233314.2999-1-hdanton@sina.com>
2022-01-28 16:50 ` Alexander Fomichev
2022-02-23 15:24 ` Thorsten Leemhuis
2022-03-06 11:19 ` [RFC] Scheduler: DMA Engine regression because of sched/fair changes #forregzbot Thorsten Leemhuis
2022-01-16 9:55 ` [RFC] Scheduler: DMA Engine regression because of sched/fair changes Thorsten Leemhuis
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