From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <463BC686.70901@yahoo.com.au> Date: Sat, 05 May 2007 09:49:26 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH] MM: implement MADV_FREE lazy freeing of anonymous memory References: <4632D0EF.9050701@redhat.com> <463B108C.10602@yahoo.com.au> <463B1FF6.1030904@redhat.com> In-Reply-To: <463B1FF6.1030904@redhat.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Linus Torvalds , linux-kernel , linux-mm , Andrew Morton , Ulrich Drepper , Jakub Jelinek List-ID: Rik van Riel wrote: > Nick Piggin wrote: > >> Rik van Riel wrote: >> >>> With lazy freeing of anonymous pages through MADV_FREE, performance of >>> the MySQL sysbench workload more than doubles on my quad-core system. >> >> >> OK, I've run some tests on a 16 core Opteron system, both sysbench with >> MySQL 5.33 (set up as described in the freebsd vs linux page), and with >> ebizzy. >> >> What I found is that, on this system, MADV_FREE performance improvement >> was in the noise when you look at it on top of the MADV_DONTNEED glibc >> and down_read(mmap_sem) patch in sysbench. > > > Interesting, very different results from my system. > > First, did you run with the properly TLB batched version of > the MADV_FREE patch? And did you make sure that MADV_FREE > takes the mmap_sem for reading? Without that, I did see > a similar thing to what you saw... Yes and yes (I initially forgot to add MADV_FREE to the down_read case and saw horrible performance!) > Secondly, I'll have to try some test runs one of the larger > systems in the lab. > > Maybe the results from my quad core Intel system are not > typical; maybe the results from your 16 core Opteron are > not typical. Either way, I want to find out :) Yep. We might have something like that here, and I'll try with some other architectures as well next week, if I can get glibc built. -- SUSE Labs, Novell Inc. -- 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