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From:   Xuewen Yan <xuewen.yan94@gmail.com>
Date:   Fri, 7 May 2021 18:26:24 +0800
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Subject: Re: [PATCH] sched/pelt: Add UTIL_AVG_UNCHANGED flag for last_enqueued_diff
To:     Vincent Guittot <vincent.guittot@linaro.org>
Cc:     Vincent Donnefort <vincent.donnefort@arm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Benjamin Segall <bsegall@google.com>,
        Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Chunyan Zhang <zhang.lyra@gmail.com>,
        Ryan Y <xuewyan@foxmail.com>
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On Fri, May 7, 2021 at 2:53 PM Vincent Guittot
<vincent.guittot@linaro.org> wrote:
>
> On Fri, 7 May 2021 at 03:36, Xuewen Yan <xuewen.yan94@gmail.com> wrote:
> >
> > On Fri, May 7, 2021 at 12:26 AM Vincent Donnefort
> > <vincent.donnefort@arm.com> wrote:
> > >
> > > On Thu, May 06, 2021 at 08:46:08PM +0800, Xuewen Yan wrote:
> > > > Hi
> > > > On Thu, May 6, 2021 at 8:28 PM Vincent Donnefort
> > > > <vincent.donnefort@arm.com> wrote:
> > > > >
> > > > > On Thu, May 06, 2021 at 07:09:36PM +0800, Xuewen Yan wrote:
> > > > > > From: Xuewen Yan <xuewen.yan@unisoc.com>
> > > > > >
> > > > > > The UTIL_AVG_UNCHANGED flag had been cleared when the task util changed.
> > > > > > And the enqueued is equal to task_util with the flag, so it is better
> > > > > > to add the UTIL_AVG_UNCHANGED flag for last_enqueued_diff.
> > >
> > > Could we change the description here a bit? I don't think this is accurately
> > > explaning the issue. Would probably be interesting to mention that by not
> > > setting the flag, which is the LSB, we add +1 to the diff. This is therefore
> > > reducing slightly UTIL_EST_MARGIN.
> >
> > ok, If you agree with this patch, I'll change it in V2.
>
> Although the impact is not significant , it's worth having an accurate
> computation. So the patch makes sense to me. Please submit a v2

Okay, I'll submit a v2 later.