Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755891AbYAVPZ3 (ORCPT ); Tue, 22 Jan 2008 10:25:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752350AbYAVPZV (ORCPT ); Tue, 22 Jan 2008 10:25:21 -0500 Received: from web32614.mail.mud.yahoo.com ([68.142.207.241]:43982 "HELO web32614.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750985AbYAVPZT (ORCPT ); Tue, 22 Jan 2008 10:25:19 -0500 X-YMail-OSG: DC.b6P0VM1lB8IM0Yc6.xTMM8skh8GxDF8uzDyiSMzCM0YQsd7bX2pTAxh6b2BoAXh7hZtYEc5TxXH6AvLqY3ofa.Q-- X-Mailer: YahooMailRC/818.31 YahooMailWebService/0.7.160 Date: Tue, 22 Jan 2008 07:25:15 -0800 (PST) From: Martin Knoblauch Subject: Re: regression: 100% io-wait with 2.6.24-rcX To: Alasdair G Kergon Cc: Linus Torvalds , Mel Gorman , Fengguang Wu , Mike Snitzer , Peter Zijlstra , jplatte@naasa.net, Ingo Molnar , linux-kernel@vger.kernel.org, "linux-ext4@vger.kernel.org" , James.Bottomley@steeleye.com, Jens Axboe , Milan Broz , Neil Brown MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Message-ID: <87924.1242.qm@web32614.mail.mud.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2716 Lines: 66 ------------------------------------------------------ Martin Knoblauch email: k n o b i AT knobisoft DOT de www: http://www.knobisoft.de ----- Original Message ---- > From: Alasdair G Kergon > To: Martin Knoblauch > Cc: Linus Torvalds ; Mel Gorman ; Fengguang Wu ; Mike Snitzer ; Peter Zijlstra ; jplatte@naasa.net; Ingo Molnar ; linux-kernel@vger.kernel.org; "linux-ext4@vger.kernel.org" ; James.Bottomley@steeleye.com; Jens Axboe ; Milan Broz ; Neil Brown > Sent: Tuesday, January 22, 2008 3:39:33 PM > Subject: Re: regression: 100% io-wait with 2.6.24-rcX > > On Fri, Jan 18, 2008 at 11:01:11AM -0800, Martin Knoblauch wrote: > > At least, rc1-rc5 have shown that the CCISS system can do well. Now > > the question is which part of the system does not cope well with the > > larger IO sizes? Is it the CCISS controller, LVM or both. I am > open > to > > suggestions on how to debug that. > > What is your LVM device configuration? > E.g. 'dmsetup table' and 'dmsetup info -c' output. > Some configurations lead to large IOs getting split up on the > way > through > device-mapper. > Hi Alastair, here is the output, the filesystem in question is on LogVol02: [root@lpsdm52 ~]# dmsetup table VolGroup00-LogVol02: 0 350945280 linear 104:2 67109248 VolGroup00-LogVol01: 0 8388608 linear 104:2 418054528 VolGroup00-LogVol00: 0 67108864 linear 104:2 384 [root@lpsdm52 ~]# dmsetup info -c Name Maj Min Stat Open Targ Event UUID VolGroup00-LogVol02 253 1 L--w 1 1 0 LVM-IV4PeE8cdxA3piC1qk79GY9PE9OC4OgmOZ4OzOgGQIdF3qDx6fJmlZukXXLIy39R VolGroup00-LogVol01 253 2 L--w 1 1 0 LVM-IV4PeE8cdxA3piC1qk79GY9PE9OC4Ogmfn2CcAd2Fh7i48twe8PZc2XK5bSOe1Fq VolGroup00-LogVol00 253 0 L--w 1 1 0 LVM-IV4PeE8cdxA3piC1qk79GY9PE9OC4OgmfYjxQKFP3zw2fGsezJN7ypSrfmP7oSvE > See if these patches make any difference: > http://www.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/ > > dm-md-merge_bvec_fn-with-separate-bdev-and-sector.patch > dm-introduce-merge_bvec_fn.patch > dm-linear-add-merge.patch > dm-table-remove-merge_bvec-sector-restriction.patch > thanks for the suggestion. Are they supposed to apply to mainline? Cheers Martin -- 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/