Re: [PATCH 1/8] x86, fpu: unlazy_fpu: don't reset thread.fpu_counter
From: Oleg Nesterov
Date: Mon Feb 16 2015 - 13:16:15 EST
On 02/16, Rik van Riel wrote:
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> Hash: SHA1
> On 02/16/2015 12:04 PM, Borislav Petkov wrote:
> > ... and so by looking at the unlazy_fpu() call sites, I think this
> > makes sense.
> > So how's that for a commit message instead:
> > --- x86, fpu, unlazy_fpu: Don't reset thread.fpu_counter
> > The "else" branch clears ->fpu_counter as a remnant of the lazy
> > FPU usage counting:
> > e07e23e1fd30 ("[PATCH] non lazy "sleazy" fpu implementation")
> > However, switch_fpu_prepare() does this now so that else branch is
> > superfluous.
> > If we do use_eager_fpu(), then this has no effect. Otherwise, if
> > we actually wanted to prevent fpu preload after the context switch
> > we would need to reset it unconditionally, even if
> > __thread_has_fpu(). ---
> > ?
> Good detective work.
> Your changelog makes sense to me.
And to me, thanks.
Should I resend?
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