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Date: Mon, 10 Oct 2011 09:32:14 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stephan Diestelhorst <stephan.diestelhorst@amd.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Jan Beulich <JBeulich@suse.com>,
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Subject: Re: [Xen-devel] [PATCH 00/10] [PATCH RFC V2] Paravirtualized
 ticketlocks
Message-ID: <20111010073214.GB29035@elte.hu>
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* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> On 10/06/2011 10:40 AM, Jeremy Fitzhardinge wrote:
> > However, it looks like locked xadd is also has better performance:  on
> > my Sandybridge laptop (2 cores, 4 threads), the add+mfence is 20% slower
> > than locked xadd, so that pretty much settles it unless you think
> > there'd be a dramatic difference on an AMD system.
> 
> Konrad measures add+mfence is about 65% slower on AMD Phenom as well.

xadd also results in smaller/tighter code, right?

Thanks,

	Ingo