linux-kernel - Re: [patch 00/10] x86/cpu: Consolidate APERF/MPERF code

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Message-ID: <CAAYoRsUKCnQy6aqVp=-n81tOh3b+o0hss7ydwDHcO_AL_rNWoA@mail.gmail.com>
Date:   Mon, 25 Apr 2022 16:20:30 -0700
From:   Doug Smythies <dsmythies@...us.net>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        "the arch/x86 maintainers" <x86@...nel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        dsmythies <dsmythies@...us.net>
Subject: Re: [patch 00/10] x86/cpu: Consolidate APERF/MPERF code

On Mon, Apr 25, 2022 at 8:45 AM Thomas Gleixner <tglx@...utronix.de> wrote:
> On Wed, Apr 20 2022 at 15:08, Doug Smythies wrote:
>> On 2022.04.19 14:11 Thomas Gleixner wrote:
>>>> That's because after the changes in this series scaling_cur_freq
>>>> returns 0 if the given CPU is idle.
>>>
>>> Which is sensible IMO as there is really no point in waking an idle CPU
>>> just to read those MSRs, then wait 20ms wake it up again to read those
>>> MSRs again.
>>
>> I totally agree.
>> It is the inconsistency for what is displayed as a function of driver/governor
>> that is my concern.
>
> Raphael suggested to move the show_cpuinfo() logic into the a/mperf
> code. See below.

Hi Thomas,

I tested the patch on top of your 10 patch set on kernel 5.18-rc3.
It addresses my consistency concerns.

Thank you

... Doug

> ---
> Subject: x86/aperfmperf: Integrate the fallback code from show_cpuinfo()
> From: Thomas Gleixner <tglx@...utronix.de>
> Date: Mon, 25 Apr 2022 15:19:29 +0200
>
...