Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll()

[Hiro Yoshioka]

From: Andi Kleen <ak@xxxxxxx>
> > Hi,
> > 
> > The following patch does not use MMX regsiters so that we don't have
> > to worry about save/restore the FPU/MMX states.
> > 
> > What do you think?
> 
> Performance will probably be bad on K7 Athlons - those have a microcoded
> movnti which is quite slow.
> 
> Also BTW I don't see any code anywhere that tests the CPUID bits,
> so your code will fail spectacularly on a PII that didn't do SSE
> (intel user copy used to be enabled on those) 
> 
> One way to solve this might be to use different code using
> alternative()
> 
> -Andi

Thanks for your comments. I'll consider it.

Regards,
  Hiro
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