Re: [PATCH 084/208] x86/fpu: Rename xsave.header::xstate_bv to 'xfeatures'

From: Borislav Petkov
Date: Thu May 07 2015 - 06:59:10 EST


On Wed, May 06, 2015 at 11:27:47AM -0700, Dave Hansen wrote:
> But we'd need to get to a point where we are calling 'xsaves' with a
> Requested Feature BitMask (aka RFBM[]) that had holes in it. As it
> stands today, we always call it with RFBM=-1 and so we always have
> XCOMP_BV = XCR0.
>
> We'd need to determine which fields are in the init state before we do
> an xsaves.

Btw, do we have any perf data as to the improvement the compacted
variant brings?

I mean, it means a bunch of jumping through hoops in SW but is it worth
it?

Thanks.

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
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