Subject: Re: [patch 3/9] Guest page hinting: volatile page cache.
From: Dave Hansen <haveblue@us.ibm.com>
To: schwidefsky@de.ibm.com
Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, akpm@osdl.org,
       nickpiggin@yahoo.com.au, frankeh@watson.ibm.com, rhim@cc.gateh.edu
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Date: Fri, 01 Sep 2006 08:37:54 -0700
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On Fri, 2006-09-01 at 17:29 +0200, Martin Schwidefsky wrote:
> On Fri, 2006-09-01 at 07:54 -0700, Dave Hansen wrote:
> > Are all of the un/likely()s in here really needed?
> 
> Well, no un/likely is really needed. But they do help the compiler to
> generate better code. It IS unlikely that a page is discarded.

I know what they're _for_. ;)

I seem to recall people being poked in the past for sprinkling too many
of these things around their code.  I just wanted to make sure that
there was some tangible reason for doing it, other than speculative
performance optimization.

-- Dave

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