linux-kernel - Re: [PATCH RFC 1/5] x86,fpu: split prev/next task fpu state handling

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Date:   Sat, 1 Oct 2016 16:26:47 -0700
From:   Andy Lutomirski <luto@...capital.net>
To:     Rik van Riel <riel@...hat.com>
Cc:     "H. Peter Anvin" <hpa@...or.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...e.de>,
        Paolo Bonzini <pbonzini@...hat.com>, X86 ML <x86@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>
Subject: Re: [PATCH RFC 1/5] x86,fpu: split prev/next task fpu state handling

On Oct 1, 2016 1:49 PM, <riel@...hat.com> wrote:
>
> From: Rik van Riel <riel@...hat.com>
>
> Move all handling of the next state FPU state handling into
> switch_fpu_finish, in preparation for more lazily switching
> FPU states.
>
> CR0.TS state is mirrored in a per-cpu variable, instead of
> being passed around in a local variable, because that will
> not be possible later in the series.

This seems reasonable in principle, but IMO it would be less scary if
you rebased onto this:

https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=x86/fpu

Because the amount of testing needed and the amount of code that gets
rearranged would be reduced.  Want to fold those patches into you
series?  I can also just send them in directly, although this is an
awkward time to do so.

--Andy