Re: [PATCH v5 28/28] x86/fpu/amx: Clear the AMX state when appropriate

[Len Brown]

On Mon, May 24, 2021 at 10:10 AM Dave Hansen <dave.hansen@xxxxxxxxx> wrote:

> On 5/23/21 8:13 PM, Andy Lutomirski wrote:
> >
> > Can we do this just when going idle?
>
> Chang, you might also want to talk with folks that do scheduler
> performance work (I've cc'd Tim).  I know we're always fighting to trim
> down the idle and wakeup paths.  There might be no other alternative,
> but unconditionally forcing an AMX XRSTOR on return from idle might be
> considered nasty.

I'm not excited about burdening the generic idle path with a CPU
feature specific check
that would need to be checked on every idle entry.

thanks,
Len Brown, Intel Open Source Technology Center