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From: Ulrich Drepper <drepper@redhat.com>
To: Andre Przywara <andre.przywara@amd.com>
Cc: Ricardo Martins <ricardo.martins.br@gmail.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: KVM Processor cache size
Date: Mon, 02 Aug 2010 06:49:47 -0700	[thread overview]
Message-ID: <4C56CCFB.204@redhat.com> (raw)
In-Reply-To: <4C56BF6F.9040402@amd.com>

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On 08/02/2010 05:51 AM, Andre Przywara wrote:
> Do you have a use case for the cache size or is this just out of curiosity?

glibc uses the cache size information returned by cpuid to perform
optimizations.  For instance, copy operations which would pollute too
much of the cache because they are large will use non-temporal
instructions.  There are real performance benefits.  Even the synthetic
CPU provided by qemu should have a more realistic value.

- -- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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  parent reply	other threads:[~2010-08-02 13:49 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-02 11:45 KVM Processor cache size Ricardo Martins
2010-08-02 12:51 ` Andre Przywara
2010-08-02 13:08   ` Avi Kivity
2010-08-02 22:22     ` Anthony Liguori
2010-08-02 22:35       ` Andre Przywara
2010-08-02 23:38         ` Anthony Liguori
2010-08-03  5:38           ` Avi Kivity
2010-08-03  5:33       ` Avi Kivity
2010-08-02 22:25     ` Anthony Liguori
2010-08-02 22:54       ` Andre Przywara
2010-08-02 23:40         ` Anthony Liguori
2010-08-03  5:41           ` Avi Kivity
2010-08-02 13:49   ` Ulrich Drepper [this message]
2010-08-02 18:38     ` Ricardo Martins
2010-08-02 22:24       ` Andre Przywara
2010-08-02 22:15     ` Andre Przywara
2010-08-02 22:23     ` Anthony Liguori
2010-08-02 22:42       ` Andre Przywara
2010-08-02 23:36         ` Anthony Liguori
2010-08-03  6:25           ` Dor Laor

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