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From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
To: Adrian Bunk <bunk@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sam Ravnborg <sam@ravnborg.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: X86_HT always enable on X86_64 SMP
Date: Wed, 27 Feb 2008 14:16:56 -0800	[thread overview]
Message-ID: <47C5E158.5080900@ct.jp.nec.com> (raw)
In-Reply-To: <20080227215816.GX29269@cs181133002.pp.htv.fi>

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?

Thanks,
Hiroshi Shimamoto

  reply	other threads:[~2008-02-27 22:17 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-27 21:16 [PATCH] x86: X86_HT always enable on X86_64 SMP Hiroshi Shimamoto
2008-02-27 21:26 ` Adrian Bunk
2008-02-27 21:30   ` H. Peter Anvin
2008-02-27 21:58     ` Adrian Bunk
2008-02-27 22:16       ` Hiroshi Shimamoto [this message]
2008-02-27 22:37         ` Adrian Bunk
2008-02-27 22:00     ` Yinghai Lu
2008-02-27 22:31       ` Hiroshi Shimamoto

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