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From: "H. Peter Anvin" <hpa@zytor.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>,
	Lin Ming <ming.m.lin@intel.com>, Ingo Molnar <mingo@elte.hu>,
	Andi Kleen <andi@firstfloor.org>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/7] perf: Check if HT is supported and enabled
Date: Tue, 04 Jan 2011 11:00:23 -0800	[thread overview]
Message-ID: <4D236E47.5080500@zytor.com> (raw)
In-Reply-To: <1294149501.2016.141.camel@laptop>

On 01/04/2011 05:58 AM, Peter Zijlstra wrote:
> On Tue, 2011-01-04 at 14:52 +0100, Stephane Eranian wrote:
>>
>> Couldn't you simply over-provision, and then when the CPU is online, use my
>> ht_enabled statement to figure out whether or not you need to handle the sharing
>> issue? 
> 
> That's pretty much what Lin's latest does:
> 
>  X86_FEATURE_HT && smp_num_siblings > 1
> 
> shows the CPU is capable of HT and will allocate the needed resources.
> 

>From the sound of it, it doesn't seem like it's worth optimizing out the
fairly small memory allocation.

	-hpa


  parent reply	other threads:[~2011-01-04 19:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-27 15:36 [PATCH 4/7] perf: Check if HT is supported and enabled Lin Ming
     [not found] ` <AANLkTimp9VgD4qhOVmq-k1Ckzti9eeV8pf6Jvt5YB6nx@mail.gmail.com>
2010-12-28  8:51   ` Lin Ming
2011-01-03 10:58     ` Peter Zijlstra
2011-01-03 15:21       ` Andi Kleen
2011-01-03 19:53       ` H. Peter Anvin
2011-01-04 11:10         ` Peter Zijlstra
2011-01-04 13:38           ` Stephane Eranian
2011-01-04 13:44             ` Peter Zijlstra
2011-01-04 13:52               ` Stephane Eranian
2011-01-04 13:58                 ` Peter Zijlstra
2011-01-04 15:35                   ` Stephane Eranian
2011-01-04 19:00                   ` H. Peter Anvin [this message]
2011-01-05  5:45                 ` Lin Ming
2011-01-05 10:08                   ` Peter Zijlstra
2011-01-04 18:55           ` Valdis.Kletnieks

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