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

From: Hiroshi Shimamoto
Date: Wed Feb 27 2008 - 17:31:33 EST


Yinghai Lu wrote:
> 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.

yes on 64-bit. On 32-bit MK8 doesn't affect X86_HT.

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