Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932561AbZJFNPi (ORCPT ); Tue, 6 Oct 2009 09:15:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932484AbZJFNPh (ORCPT ); Tue, 6 Oct 2009 09:15:37 -0400 Received: from cantor.suse.de ([195.135.220.2]:37241 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932478AbZJFNPf (ORCPT ); Tue, 6 Oct 2009 09:15:35 -0400 From: Nikanth Karthikesan Organization: suse.de To: Jens Axboe Subject: Re: [bisected] commit: a9327cac440be4d8333bba975cbbf76045096275 causes iostat output Date: Tue, 6 Oct 2009 18:44:01 +0530 User-Agent: KMail/1.12.0 (Linux/2.6.32-rc3-0.1-default; KDE/4.3.0; x86_64; ; ) Cc: Corrado Zoccolo , "Linux-Kernel" References: <4e5e476b0910040349l21b69a97o7a11b2138bc8f573@mail.gmail.com> <20091004190653.GH26573@kernel.dk> In-Reply-To: <20091004190653.GH26573@kernel.dk> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200910061844.01499.knikanth@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3466 Lines: 86 On Monday 05 October 2009 00:36:53 Jens Axboe wrote: > 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. > Thanks for reporting. > 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! Sorry. I missed converting to 2 seperate variables at @@ -1030,7 +1030,7 @@ static void part_round_stats_single(int cpu, struct hd_struct *part, if (now == part->stamp) return; - if (part->in_flight) { + if (part_in_flight(part)) { __part_stat_add(cpu, part, time_in_queue, part_in_flight(part) * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); which caused this regression. I would post the patch with this fix included. Thanks Nikanth -- 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/