From: Eric Sandeen Subject: Re: jbd/jbd2 performance improvements Date: Thu, 16 Oct 2008 07:39:04 -0500 Message-ID: <48F735E8.7060803@redhat.com> References: <48F62893.9060606@redhat.com> <18678.55651.556822.187508@frecb006361.adech.frec.bull.fr> <48F72E5F.2050409@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Solofo.Ramangalahy@bull.net, "Theodore Ts'o" , linux-ext4@vger.kernel.org To: Ric Wheeler Return-path: Received: from mx2.redhat.com ([66.187.237.31]:44480 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752293AbYJPMkA (ORCPT ); Thu, 16 Oct 2008 08:40:00 -0400 In-Reply-To: <48F72E5F.2050409@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Ric Wheeler wrote: > Solofo.Ramangalahy@bull.net wrote: >> Hi Ric, >> >> >>>>>>> On Wed, 15 Oct 2008 13:29:55 -0400, Ric Wheeler said: >>>>>>> >> Ric> We are going to try and poke at this - do you suspect a single or >> Ric> multi-threaded test would work best? >> >> I've performed some tests: >> http://www.bullopensource.org/ext4/20081013-2.6.27-rc9-ext4-1-akpm-fix-run6/ >> http://www.bullopensource.org/ext4/20081013-2.6.27-rc9-ext4-1-akpm-fix-run6/results_sorted.txt.html >> >> I now realize that the results may not be valid since I used kvm, but >> they do show variation wrt. the number of threads. >> >> So you may want to test both single and multi-threaded. >> >> > A very thorough test, but the results don't seem to point to a > consistent winner. > > I agree that running without KVM in the picture might be very > interesting. Eric has some similar tests underway, I think that his > results were also inconclusive so far... Yep, I've yet to find an fs_mark invocation, at least, which shows a clear winner. I also ran w/ akpm's suggested io_schedule watcher patch and never see us waiting on this lock (I did set it to 1s though, which is probably too long for my storage). -Eric