Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757794AbZJDTHb (ORCPT ); Sun, 4 Oct 2009 15:07:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757753AbZJDTHa (ORCPT ); Sun, 4 Oct 2009 15:07:30 -0400 Received: from brick.kernel.dk ([93.163.65.50]:39631 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757748AbZJDTHa (ORCPT ); Sun, 4 Oct 2009 15:07:30 -0400 Date: Sun, 4 Oct 2009 21:06:53 +0200 From: Jens Axboe To: Corrado Zoccolo Cc: Linux-Kernel , knikanth@suse.de Subject: Re: [bisected] commit: a9327cac440be4d8333bba975cbbf76045096275 causes iostat output Message-ID: <20091004190653.GH26573@kernel.dk> References: <4e5e476b0910040349l21b69a97o7a11b2138bc8f573@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4e5e476b0910040349l21b69a97o7a11b2138bc8f573@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2805 Lines: 68 On Sun, Oct 04 2009, Corrado Zoccolo wrote: > Hi, > with 2.6.32-rc1 I started getting the following strange output from > "iostat -kx 2": > Linux 2.6.31bisect (et2) 04/10/2009 _i686_ (2 CPU) > > avg-cpu: %user %nice %system %iowait %steal %idle > 10,70 0,00 3,16 15,75 0,00 70,38 > > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s > avgrq-sz avgqu-sz await svctm %util > sda 18,22 0,00 0,67 0,01 14,77 0,02 > 43,94 0,01 10,53 39043915,03 2629219,87 > sdb 60,89 9,68 50,79 3,04 1724,43 50,52 > 65,95 0,70 13,06 488437,47 2629219,87 > > avg-cpu: %user %nice %system %iowait %steal %idle > 2,72 0,00 0,74 0,00 0,00 96,53 > > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s > avgrq-sz avgqu-sz await svctm %util > sda 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 100,00 > sdb 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 100,00 > > avg-cpu: %user %nice %system %iowait %steal %idle > 6,68 0,00 0,99 0,00 0,00 92,33 > > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s > avgrq-sz avgqu-sz await svctm %util > sda 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 100,00 > sdb 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 100,00 > > avg-cpu: %user %nice %system %iowait %steal %idle > 4,40 0,00 0,73 1,47 0,00 93,40 > > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s > avgrq-sz avgqu-sz await svctm %util > sda 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 100,00 > sdb 0,00 4,00 0,00 3,00 0,00 28,00 > 18,67 0,06 19,50 333,33 100,00 > > Global values for service time and utilization are garbage. For > interval values, utilization is always 100%, and service time is > higher than normal. > > I bisected it down to: > [a9327cac440be4d8333bba975cbbf76045096275] Seperate read and write > statistics of in_flight requests > and verified that reverting just that commit indeed solves the issue > on 2.6.32-rc1. I've reverted this commit since the next -rc is close, then we can debug and potentially re-introduce this change after that. Thanks a lot for reporting and bisecting it, too! -- Jens Axboe -- 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/