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    SubjectRE: [PATCH v3 1/2] cpu/smt: add a notifier to notify the SMT changes
    Date
    [AMD Official Use Only - General]



    > -----Original Message-----
    > From: Peter Zijlstra <peterz@infradead.org>
    > Sent: Wednesday, March 29, 2023 4:50 PM
    > To: Yang, WenYou <WenYou.Yang@amd.com>
    > Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian
    > <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; Quan, Evan
    > <Evan.Quan@amd.com>; Limonciello, Mario <Mario.Limonciello@amd.com>;
    > bp@alien8.de; jpoimboe@kernel.org; Phillips, Kim <kim.phillips@amd.com>;
    > tglx@linutronix.de; Yuan, Perry <Perry.Yuan@amd.com>; Liang, Richard qi
    > <Richardqi.Liang@amd.com>; Li, Ying <YING.LI@amd.com>; Liu, Kun
    > <Kun.Liu2@amd.com>; gpiccoli@igalia.com; amd-gfx@lists.freedesktop.org;
    > linux-kernel@vger.kernel.org
    > Subject: Re: [PATCH v3 1/2] cpu/smt: add a notifier to notify the SMT changes
    >
    > Caution: This message originated from an External Source. Use proper caution
    > when opening attachments, clicking links, or responding.
    >
    >
    > On Wed, Mar 29, 2023 at 07:23:29AM +0000, Yang, WenYou wrote:
    > > [AMD Official Use Only - General]
    >
    > ^^^ that has no business being in a public email.
    >
    > > Hi Peter,
    > >
    > > Thank you for your review.
    > >
    > > The purpose of the patch set is to improve the performance when playing
    > game for some AMD APUs with SMT enabled/disabled.
    > >
    > > When change the SMT state on the fly through " echo on/off >
    > /sys/devices/system/cpu/smt/control", the kernel needs to send a message to
    > notify PMFW to adjust a variable's value, which impacts the performance.
    >
    > When top posting I normally ignore the email. When not wrapping email I
    > typically get cranky. You 'win' *3* 'I cannot use email' trophies in a singly try.
    > Surely AMD has a HOWTO somewhere you can read?

    Yes. It is my fault. Sorry.

    >
    > So what do you want to have happen when someone goes and manually offlines
    > all the SMT siblings using /sys/devices/system/cpu/cpu*/online
    > ?

    I don't consider this situation. Any suggestions will be deeply appreciated.

    >
    > I'm thinking that wants the same PMFW (whatever the heck that is) notification
    > change done, right?
    >
    > If the answer is "yes", then your patch does not meet the goals and is
    > inadequate.

    Yes. Need to improve.

    Thank you.
    Wenyou

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