Re: [PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace

From: Borislav Petkov
Date: Fri Apr 12 2019 - 12:22:24 EST


On Fri, Apr 12, 2019 at 05:24:37PM +0200, Sebastian Andrzej Siewior wrote:
> Isn't it called from fpu__clear()?

$ git grep trace_x86_fpu_activate_state
$

all 23 patches applied. Grepping the later patches doesn't give
trace_x86_fpu_activate_state() either.

> > Shouldn't it be called below, before fpregs_activate() because
> > fpregs_activate() does trace_x86_fpu_regs_activated()?
>
> Why? fpu__initialize() wipes the FPU state and starts from zero.
> fpregs_mark_activate() on the other hand marks this FPU context is
> currently active.

Well, then the naming still needs adjusting.

"trace_x86_fpu_activate_state" reads to me like the state is being
activated here, at the call site. And fpregs_mark_activate() marks which
*fpu is the active one.

Hmm.

--
Regards/Gruss,
Boris.

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