linux-kernel - Re: [PATCH v1] Revert "cpufreq: schedutil: Move max CPU capacity to sugov

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Date:   Sun, 27 Nov 2022 13:06:42 +0100
From:   Thorsten Leemhuis <regressions@...mhuis.info>
To:     "regressions@...ts.linux.dev" <regressions@...ts.linux.dev>
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] Revert "cpufreq: schedutil: Move max CPU capacity to
 sugov_policy" #forregzbot

On 20.11.22 19:07, Thorsten Leemhuis wrote:
> On 10.11.22 20:57, Sam Wu wrote:
>> This reverts commit 6d5afdc97ea71958287364a1f1d07e59ef151b11.
>>
>> On a Pixel 6 device, it is observed that this commit increases
>> latency by approximately 50ms, or 20%, in migrating a task
>> that requires full CPU utilization from a LITTLE CPU to Fmax
>> on a big CPU. Reverting this change restores the latency back
>> to its original baseline value.
>>
>> Fixes: 6d5afdc97ea7 ("cpufreq: schedutil: Move max CPU capacity to sugov_policy")
>> Cc: Lukasz Luba <lukasz.luba@....com>
>> Cc: Saravana Kannan <saravanak@...gle.com>
>> Cc: Isaac J. Manjarres <isaacmanjarres@...gle.com>
>> Signed-off-by: Sam Wu <wusamuel@...gle.com>
> 
> Thanks for the report. To be sure below issue doesn't fall through the
> cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression
> tracking bot:
> 
> #regzbot ^introduced 6d5afdc97ea7
> #regzbot title cpufreq: schedutil: improved latency on Pixel 6
> #regzbot ignore-activity

#regzbot fixed-by: cdcc5ef26b3