From: Jens Axboe <jens.axboe@oracle.com>
To: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Linux-Kernel <linux-kernel@vger.kernel.org>, knikanth@suse.de
Subject: Re: [bisected] commit: a9327cac440be4d8333bba975cbbf76045096275 causes iostat output
Date: Sun, 4 Oct 2009 21:06:53 +0200 [thread overview]
Message-ID: <20091004190653.GH26573@kernel.dk> (raw)
In-Reply-To: <4e5e476b0910040349l21b69a97o7a11b2138bc8f573@mail.gmail.com>
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
next prev parent reply other threads:[~2009-10-04 19:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-04 10:49 Corrado Zoccolo
2009-10-04 19:06 ` Jens Axboe [this message]
2009-10-06 13:14 ` Nikanth Karthikesan
2009-10-06 13:16 ` [PATCH linux-2.6-block#for-linus] Seperate read and write statistics of in_flight requests v2 Nikanth Karthikesan
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