From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 3 Apr 2005 21:05:57 +0100 (IST) From: Mel Gorman Subject: Re: AIM9 slowdowns between 2.6.11 and 2.6.12-rc1 (probably false positive) In-Reply-To: <1112555170.7189.34.camel@localhost> Message-ID: References: <1112555170.7189.34.camel@localhost> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Linux Memory Management List , Linux Kernel Mailing List List-ID: On Sun, 3 Apr 2005, Dave Hansen wrote: > On Sun, 2005-04-03 at 15:37 +0100, Mel Gorman wrote: > > While testing the page placement policy patches on 2.6.12-rc1, I noticed > > that aim9 is showing significant slowdowns on page allocation-related > > tests. An excerpt of the results is at the end of this mail but it shows > > that page_test is allocating 18000 less pages. > > > > I did not check who has been recently changing the buddy allocator but > > they might want to run a benchmark or two to make sure this is not > > something specific to my setup. > > Can you get some kernel profiles to see what, exactly, is causing the > decreased performance? Also, what kind of system do you have? Does > backing this out help? If not, can you test some BK snapshots to see > when this started occurring? > > http://linus.bkbits.net:8080/linux-2.5/cset@422de02c1628MP_noKSum9sGlTaC-Q > The machine is a quad xeon with P III 733 processors. I don't have profile information available as I wasn't collecting as I went along. However, backing out the patch made little difference However, I reran the test on 2.6.11 and this time the performance difference was a lot less. Something else must have been happening when I collected the first set of poor results. I'll revisit this when I'm next working on kernel stuff and see can I reproduce it again reliably. -- Mel Gorman Part-time Phd Student Java Applications Developer University of Limerick IBM Dublin Software Lab -- 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: aart@kvack.org