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Subject: Re: [PATCH 4/7] perf: Check if HT is supported and enabled
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Stephane Eranian <eranian@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>, Lin Ming <ming.m.lin@intel.com>,
        Ingo Molnar <mingo@elte.hu>, Andi Kleen <andi@firstfloor.org>,
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Date: Tue, 04 Jan 2011 14:58:21 +0100
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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.