From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Superpages Project - sourceforge.net/projects/linuxsuperpages From: Peter Zijlstra In-Reply-To: References: Content-Type: text/plain Date: Wed, 15 Oct 2008 15:00:47 +0200 Message-Id: <1224075647.28131.6.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "Wildman, Tom" Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "alan@redhat.com" , Mel Gorman List-ID: 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org