From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Zhang Qiao <zhangqiao22@huawei.com>,
linux-kernel@vger.kernel.org, mingo@redhat.com,
juri.lelli@redhat.com, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
bristot@redhat.com, vschneid@redhat.com, rkagan@amazon.de
Subject: Re: [PATCH v2] sched/fair: sanitize vruntime of entity being migrated
Date: Thu, 9 Mar 2023 15:36:56 +0100 [thread overview]
Message-ID: <ZAnvCGdlOrWbIC/o@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230309142825.GB273121@hirez.programming.kicks-ass.net>
On Thu, Mar 09, 2023 at 03:28:25PM +0100, Peter Zijlstra wrote:
> On Thu, Mar 09, 2023 at 02:34:05PM +0100, Vincent Guittot wrote:
>
> > Then, even if we don't clear exec_start before migrating and keep
> > current value to be used in place_entity on the new cpu, we can't
> > compare the rq_clock_task(rq_of(cfs_rq)) of 2 different rqs AFAICT
>
> Blergh -- indeed, irq and steal time can skew them between CPUs :/
> I suppose we can fudge that... wait_start (which is basically what we're
> making it do) also does that IIRC.
>
> I really dislike having this placement muck spreadout like proposed.
Also, I think we might be over-engineering this, we don't care about
accuracy at all, all we really care about is 'long-time'.
next prev parent reply other threads:[~2023-03-09 14:38 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-06 13:24 [PATCH v2] sched/fair: sanitize vruntime of entity being migrated Zhang Qiao
2023-03-06 13:53 ` Vincent Guittot
2023-03-07 10:26 ` Vincent Guittot
2023-03-07 11:05 ` Zhang Qiao
2023-03-07 13:41 ` Zhang Qiao
2023-03-08 8:01 ` Vincent Guittot
2023-03-08 12:55 ` Vincent Guittot
2023-03-09 8:37 ` Zhang Qiao
2023-03-09 9:09 ` Dietmar Eggemann
2023-03-09 9:30 ` Zhang Qiao
2023-03-09 10:48 ` Vincent Guittot
2023-03-09 14:23 ` Zhang Qiao
2023-03-07 2:16 ` kernel test robot
2023-03-07 12:45 ` Dietmar Eggemann
2023-03-07 14:06 ` Zhang Qiao
2023-03-09 9:43 ` Zhang Qiao
2023-03-08 14:33 ` Chen Yu
2023-03-09 13:05 ` Peter Zijlstra
2023-03-09 13:34 ` Vincent Guittot
2023-03-09 14:28 ` Peter Zijlstra
2023-03-09 14:36 ` Peter Zijlstra [this message]
2023-03-09 15:14 ` Vincent Guittot
2023-03-10 14:29 ` Vincent Guittot
2023-03-11 9:57 ` Zhang Qiao
2023-03-13 14:23 ` Vincent Guittot
2023-03-14 11:03 ` Zhang Qiao
2023-03-14 13:26 ` Vincent Guittot
2023-03-14 13:38 ` Zhang Qiao
2023-03-14 13:39 ` Vincent Guittot
2023-03-14 15:32 ` Vincent Guittot
2023-03-15 9:16 ` Zhang Qiao
2023-03-15 15:30 ` Vincent Guittot
2023-03-13 9:06 ` Dietmar Eggemann
2023-03-13 18:17 ` Dietmar Eggemann
2023-03-14 7:41 ` Vincent Guittot
2023-03-14 12:07 ` Peter Zijlstra
2023-03-14 13:24 ` Vincent Guittot
2023-03-14 17:16 ` Peter Zijlstra
2023-03-15 7:18 ` Vincent Guittot
2023-03-15 8:42 ` Vincent Guittot
2023-03-15 10:15 ` Dietmar Eggemann
2023-03-15 10:21 ` Vincent Guittot
2023-03-15 13:35 ` Dietmar Eggemann
2023-03-15 15:32 ` Vincent Guittot
2023-03-14 13:29 ` Dietmar Eggemann
2023-03-14 13:37 ` Dietmar Eggemann
-- strict thread matches above, loose matches on Subject: below --
2023-03-17 16:08 Vincent Guittot
2023-03-18 7:45 ` Zhang Qiao
2023-03-20 12:29 ` Dietmar Eggemann
2023-03-20 13:26 ` Vincent Guittot
2023-03-21 10:02 ` Peter Zijlstra
2023-03-21 10:29 ` Dietmar Eggemann
2023-03-21 10:49 ` Peter Zijlstra
2023-03-21 11:12 ` Vincent Guittot
2023-03-21 11:13 ` Dietmar Eggemann
2023-03-21 12:26 ` Peter Zijlstra
2023-03-21 12:28 ` Peter Zijlstra
2023-03-21 12:38 ` Vincent Guittot
2023-03-24 4:05 ` Chen Yu
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