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From: Peter Zijlstra <peterz@infradead.org>
To: "Wildman, Tom" <tom.wildman@hp.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"alan@redhat.com" <alan@redhat.com>, Mel Gorman <mel@skynet.ie>
Subject: Re: Superpages Project  -  sourceforge.net/projects/linuxsuperpages
Date: Wed, 15 Oct 2008 15:00:47 +0200	[thread overview]
Message-ID: <1224075647.28131.6.camel@twins> (raw)
In-Reply-To: <F9E7AD49A6823D4AA5A36E1DE32F0F9B27570B8CBC@GVW1092EXB.americas.hpqcorp.net>

On Wed, 2008-10-15 at 01:51 +0000, Wildman, Tom wrote:
> A new project has been created at SourceForge with an implementation
> of the Rice University's Superpages FreeBSD prototype that has been
> ported to the 2.6 Linux kernel for IA64, x86-64, and x86-32.
> 
> The project can be found at:
> http://sourceforge.net/projects/linuxsuperpages
> 
> The major benefit of supporting Superpages is increased memory reach
> of the processor's TLB, which reduces the number of TLB misses in
> applications that have large data sets.  Some benchmarks have been
> improved 20% in execution time.
> 
> Reference www.cs.rice.edu/~jnavarro/superpages/ for more information
> about the Rice University's Superpages project.
> 
> The project is being made available to the Open Source community to
> share the implementation and knowledge.  With the enhancements to the
> x86 architectures to support multiple and large page sizes there
> should be increased interest in this functionality.

How are you proposing to address the fun issues like online compaction
etc. ?

Furthermore, what's the added advantage of dynamic superpages over
exlpicit superpage support, eg. though the use of libhugetlb?

Unless you realize online compaction and add a kind of extend allocation
to the page allocator there will hardly ever be a situation where you
can promote a page.

All of which is rather expensive to do, changing the application might
be easier and deliver better performance gains.

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      parent reply	other threads:[~2008-10-15 13:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-15  1:51 Wildman, Tom
2008-10-15  8:29 ` Alan Jenkins
2008-10-15  8:53   ` Bert Wesarg
2008-10-15 11:17   ` Wildman, Tom
2008-10-15 13:00 ` Peter Zijlstra [this message]

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