Messages in this thread | | | Date | Thu, 28 Feb 2008 00:37:40 +0200 | From | Adrian Bunk <> | Subject | Re: [PATCH] x86: X86_HT always enable on X86_64 SMP |
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On Wed, Feb 27, 2008 at 02:16:56PM -0800, Hiroshi Shimamoto wrote: > Adrian Bunk wrote: > > On Wed, Feb 27, 2008 at 01:30:59PM -0800, H. Peter Anvin wrote: > >> Adrian Bunk wrote: > >>> On Wed, Feb 27, 2008 at 01:16:30PM -0800, Hiroshi Shimamoto wrote: > >>>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> > >>>> > >>>> 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. > > > > These are the already existing scheduler related variables that are > > only a part of the X86_HT usages. > > > >> It's not particularly clear to me what X86_HT is meant to be used for > >> anymore at all. > > > > grep through the source code and you find it is sometimes used for > > hyperthreading and sometimes for multicore. > > > > I don't care whether X86_HT gets splitted or perhaps even removed, but > > any change to it should remove the status quo of it having two different > > semantics. > > OK, you say "Don't mix two different semantics into one variable X86_HT", right?
Exactly.
This mixing is not your fault since it's an older problem, but instead of your suggested patch we should fix it properly.
> Thanks, > Hiroshi Shimamoto
cu Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed
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