linux-kernel - Re: [PATCH v2 2/2] x86/xstate: Make AVX512 status tracking more accurate

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Message-ID: <CAFUsyfJGxpLz14pZ-_nC-3651WaeZeb6p1yteCP2J4=aTKRsrA@mail.gmail.com>
Date:   Wed, 27 Oct 2021 11:28:07 -0500
From:   Noah Goldstein <goldstein.w.n@...il.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     tglx@...utronix.de, mingo@...hat.com, X86 ML <x86@...nel.org>,
        hpa@...or.com, Andy Lutomirski <luto@...nel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] x86/xstate: Make AVX512 status tracking more accurate

On Wed, Oct 27, 2021 at 6:07 AM Borislav Petkov <bp@...en8.de> wrote:
>
> On Fri, Oct 15, 2021 at 03:47:17PM -0500, Noah Goldstein wrote:
> > This patch splits the timestamps for tracking the AVX512 status into
>
> For future submissions, please avoid having "This patch" or "This
> commit" in the commit message. It is tautologically useless.

Got it. Thanks.
>
> ...
>
> > @@ -1282,8 +1292,27 @@ static void avx512_status(struct seq_file *m, struct task_struct *task)
> >                       delta = LONG_MAX;
> >               delta = jiffies_to_msecs(delta);
> >       }
> > +     return delta;
> > +}
> >
> > -     seq_put_decimal_ll(m, "AVX512_elapsed_ms:\t", delta);
>
> Regardless of whether I think this exposing of AVX512 usage is silly
> or not, we do not break userspace by changing those strings which some
> script or tool already probably relies upon.

Fixed. Added 'delta_unified' which will report the most recent usage of
either.

>
> --
> Regards/Gruss,
>     Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette