Re: [PATCH] x86: X86_HT always enable on X86_64 SMP

From: Yinghai Lu
Date: Wed Feb 27 2008 - 17:00:37 EST


On Wed, Feb 27, 2008 at 1:30 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Adrian Bunk wrote:
> > On Wed, Feb 27, 2008 at 01:16:30PM -0800, Hiroshi Shimamoto wrote:
> >> From: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
> >>
> >> X86_HT is used for hyperthreading or multicore on 32-bit.
> >> The X86_HT on 64-bit is different from 32-bit, it means hyperthreading only.
> >> And X86_HT is not used on 64-bit except from cpu/initel_cacheinfo.c.
> >>
> >> Unify X86_HT for hyperthreading or multicore.
> >> Turn X86_HT on when X86_64 and SMP are enabled.
> >
> > Please fix it properly instead - fiddling around with it the way you do
> > only asks for trouble in the future.
> >
> > What we need are two different variables for:
> > - hyperthreading and
> > - multicore
> >
>
> He does, and calls them SCHED_SMT and SCHED_MC respectively.
>
> It's not particularly clear to me what X86_HT is meant to be used for
> anymore at all.

he made X86_HT can be enabled when only Opteron supported is enabled.

it should be stated in the comments.
YH
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