linux-kernel - Re: [PATCH v2] cpufreq: schedutil: Examine the correct CPU when we update util

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Date:   Fri, 3 Nov 2017 09:10:22 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Chris Redpath <chris.redpath@....com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Morten Rasmussen <morten.rasmussen@....com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH v2] cpufreq: schedutil: Examine the correct CPU when we
 update util

On 02-11-17, 12:06, Chris Redpath wrote:
> According to my diff, this was the commit which switched from assigning
> the values directly (and not overwriting the cpu member, which was
> introduced in the other commit you reference) to using a memset and
> clearing the whole struct.

I understand what you want to convey here but the log says something
else according to me. It says:

"Since: 4296f23ed cpufreq: schedutil: Fix per-CPU structure
initialization in sugov_start(), We lost the value of sg_cpu->cpu
which is assigned during sugov_register."

Reading this line it looks like sg_cpu->cpu was screwed up by
4296f23ed, which happened in 4.9. But the sg_cpu->cpu field itself got
added in 4.14 and so I think we should write it differently.

If I were you, I wouldn't mention 4296f23ed here at all but just say
that memset() is clearing the value of sg_cpu->cpu, fix that.

Thanks.

-- 
viresh