Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754011AbZFFAT3 (ORCPT ); Fri, 5 Jun 2009 20:19:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753169AbZFFATU (ORCPT ); Fri, 5 Jun 2009 20:19:20 -0400 Received: from rcsinet11.oracle.com ([148.87.113.123]:20157 "EHLO rgminet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752692AbZFFATT (ORCPT ); Fri, 5 Jun 2009 20:19:19 -0400 Date: Fri, 5 Jun 2009 20:18:15 -0400 From: Chris Mason To: Jan Kara Cc: Jens Axboe , Frederic Weisbecker , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, david@fromorbit.com, hch@infradead.org, yanmin_zhang@linux.intel.com, richard@rsk.demon.co.uk, damien.wyart@free.fr Subject: Re: [PATCH 0/11] Per-bdi writeback flusher threads v9 Message-ID: <20090606001814.GD3824@think> Mail-Followup-To: Chris Mason , Jan Kara , Jens Axboe , Frederic Weisbecker , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, david@fromorbit.com, hch@infradead.org, yanmin_zhang@linux.intel.com, richard@rsk.demon.co.uk, damien.wyart@free.fr References: <1243511204-2328-1-git-send-email-jens.axboe@oracle.com> <20090604152040.GA6007@nowhere> <20090604120726.708a2211.akpm@linux-foundation.org> <20090604191309.GA4862@nowhere> <20090604195013.GB11363@kernel.dk> <20090604201012.GD11363@kernel.dk> <20090604223449.GA13780@nowhere> <20090605191528.GV11363@kernel.dk> <20090605211438.GA11650@duck.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090605211438.GA11650@duck.suse.cz> User-Agent: Mutt/1.5.18 (2008-05-17) X-Source-IP: abhmt004.oracle.com [141.146.116.13] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A09020A.4A29B5CA.027F:SCFSTAT5015188,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1495 Lines: 32 On Fri, Jun 05, 2009 at 11:14:38PM +0200, Jan Kara wrote: > On Fri 05-06-09 21:15:28, Jens Axboe wrote: > > On Fri, Jun 05 2009, Frederic Weisbecker wrote: > > > The result with noop is even more impressive. > > > > > > See: http://kernel.org/pub/linux/kernel/people/frederic/dbench-noop.pdf > > > > > > Also a comparison, noop with pdflush against noop with bdi writeback: > > > > > > http://kernel.org/pub/linux/kernel/people/frederic/dbench-noop-cmp.pdf > > > > OK, so things aren't exactly peachy here to begin with. It may not > > actually BE an issue, or at least now a new one, but that doesn't mean > > that we should not attempt to quantify the impact. > What looks interesting is also the overall throughput. With pdflush we > get to 2.5 MB/s + 26 MB/s while with per-bdi we get to 2.7 MB/s + 13 MB/s. > So per-bdi seems to be *more* fair but throughput suffers a lot (which > might be inevitable due to incurred seeks). > Frederic, how much does dbench achieve for you just on one partition > (test both consecutively if possible) with as many threads as have those > two dbench instances together? Thanks. Is the graph showing us dbench tput or disk tput? I'm assuming it is disk tput, so bdi may just be writing less? -chris -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/