From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17532.630.796436.488394@wombat.chubb.wattle.id.au> Date: Tue, 30 May 2006 18:29:42 +1000 From: Peter Chubb Subject: Re: [Patch 0/17] PTI: Explation of Clean Page Table Interface In-Reply-To: References: Sender: owner-linux-mm@kvack.org Return-Path: To: Jes Sorensen Cc: pauld@gelato.unsw.edu.au, linux-mm@kvack.org List-ID: >>>>> "Jes" == Jes Sorensen writes: >>>>> "Paul" == Paul Cameron Davies writes: Paul> This patch series provides the architectural independent Paul> interface. It has been tested and benchmarked for IA64 using Paul> lmbench. It also passes all relevant tests in the Linux Test Paul> Project (LTP) on IA64. This patch should 5~also compile and run Paul> for i386. To run on other architectures add CONFIG_DEFAULT_PT Paul> to the architectures config. Turn off HugeTLB. Paul> Summary of performance degradation using lmbench on IA64: ~3.5% Paul> deterioration in fork latency on IA64. ~1.0% deterioration in Paul> mmap latency on IA64 Jes> Paul, Jes> Let me just get it right as I am not sure I am reading it Jes> correctly. Are you saying that this patch causes a 3.5% fork Jes> performance degradation on ia64 or are you saying it is improving Jes> 3.5%? I believe that yes, there is currently a small performance degradation on IA64. I think we'll get that back when we put a more appropriate page table under the interface. And this is the first cut, and can be made more efficient anyway. I'm not sure whether Paul's benchmarked yet on x86, but that's the critical place where performance matters for this interface, because x86 will use the same page table (under the interface) as at present. -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au http://www.ertos.nicta.com.au ERTOS within National ICT Australia -- 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