From: David Chinner <dgc@sgi.com>
To: Torsten Kaiser <just.for.lkml@googlemail.com>
Cc: Fengguang Wu <wfg@mail.ustc.edu.cn>,
Peter Zijlstra <peterz@infradead.org>,
Maxim Levitsky <maximlevitsky@gmail.com>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
David Chinner <dgc@sgi.com>,
linux-fsdevel@vger.kernel.org
Subject: Re: writeout stalls in current -git
Date: Wed, 7 Nov 2007 10:31:14 +1100 [thread overview]
Message-ID: <20071106233114.GB995458@sgi.com> (raw)
In-Reply-To: <64bb37e0711061353g4a8b881cgd78fef3a11378b9c@mail.gmail.com>
On Tue, Nov 06, 2007 at 10:53:25PM +0100, Torsten Kaiser wrote:
> On 11/6/07, David Chinner <dgc@sgi.com> wrote:
> > Rather than vmstat, can you use something like iostat to show how busy your
> > disks are? i.e. are we seeing RMW cycles in the raid5 or some such issue.
>
> Both "vmstat 10" and "iostat -x 10" output from this test:
> procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
> r b swpd free buff cache si so bi bo in cs us sy id wa
> 2 0 0 3700592 0 85424 0 0 31 83 108 244 2 1 95 1
> -> emerge reads something, don't knwo for sure what...
> 1 0 0 3665352 0 87940 0 0 239 2 343 585 2 1 97 0
....
>
> The last 20% of the btrace look more or less completely like this, no
> other programs do any IO...
>
> 253,0 3 104626 526.293450729 974 C WS 79344288 + 8 [0]
> 253,0 3 104627 526.293455078 974 C WS 79344296 + 8 [0]
> 253,0 1 36469 444.513863133 1068 Q WS 154998480 + 8 [xfssyncd]
> 253,0 1 36470 444.513863135 1068 Q WS 154998488 + 8 [xfssyncd]
^^
Apparently we are doing synchronous writes. That would explain why
it is slow. We shouldn't be doing synchronous writes here. I'll see if
I can reproduce this.
<goes off and looks>
Yes, I can reproduce the sync writes coming out of xfssyncd. I'll
look into this further and send a patch when I have something concrete.
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
next prev parent reply other threads:[~2007-11-06 23:31 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-22 6:22 100% iowait on one of cpus in current -git Maxim Levitsky
2007-10-22 9:11 ` Paolo Ornati
2007-10-22 9:43 ` Maxim Levitsky
2007-10-22 9:41 ` Peter Zijlstra
2007-10-22 9:59 ` Maxim Levitsky
2007-10-22 10:22 ` Peter Zijlstra
2007-10-22 10:40 ` Maxim Levitsky
2007-10-22 10:55 ` Fengguang Wu
2007-10-22 10:55 ` Fengguang Wu
2007-10-22 10:58 ` Maxim Levitsky
2007-10-22 11:19 ` Fengguang Wu
2007-10-22 11:19 ` Fengguang Wu
2007-10-22 12:21 ` Maxim Levitsky
2007-10-22 12:37 ` Fengguang Wu
2007-10-22 12:37 ` Fengguang Wu
2007-10-22 13:05 ` Maxim Levitsky
2007-10-22 13:10 ` Fengguang Wu
2007-10-22 13:10 ` Fengguang Wu
2007-10-22 13:28 ` Maxim Levitsky
2007-10-22 13:41 ` Fengguang Wu
2007-10-22 13:41 ` Fengguang Wu
2007-10-31 15:22 ` Torsten Kaiser
2007-11-01 7:57 ` Fengguang Wu
2007-11-01 7:57 ` Fengguang Wu
2007-11-01 18:20 ` Torsten Kaiser
2007-11-01 19:00 ` Torsten Kaiser
2007-11-02 2:21 ` writeout stalls " Fengguang Wu
2007-11-02 2:21 ` Fengguang Wu
2007-11-02 7:50 ` Torsten Kaiser
2007-11-02 10:15 ` Peter Zijlstra
2007-11-02 10:33 ` Fengguang Wu
2007-11-02 10:33 ` Fengguang Wu
2007-11-05 23:57 ` Andrew Morton
2007-11-06 10:20 ` Peter Zijlstra
2007-11-06 16:25 ` Patch tags [was writeout stalls in current -git] Jonathan Corbet
2007-11-06 17:03 ` Balbir Singh
2007-11-06 23:26 ` Adrian Bunk
2007-11-09 16:10 ` Jonathan Corbet
2007-11-09 16:19 ` Adrian Bunk
2007-11-02 19:22 ` writeout stalls in current -git Torsten Kaiser
2007-11-02 20:43 ` David Chinner
2007-11-02 21:02 ` Torsten Kaiser
2007-11-04 11:19 ` Torsten Kaiser
2007-11-05 1:45 ` David Chinner
2007-11-05 7:01 ` Torsten Kaiser
2007-11-05 18:27 ` Torsten Kaiser
2007-11-06 4:25 ` David Chinner
2007-11-06 7:10 ` Torsten Kaiser
2007-11-06 19:01 ` Peter Zijlstra
2007-11-06 20:26 ` Torsten Kaiser
2007-11-06 9:17 ` Fengguang Wu
2007-11-06 9:17 ` Fengguang Wu
2007-11-06 21:53 ` Torsten Kaiser
2007-11-06 23:31 ` David Chinner [this message]
2007-11-07 2:13 ` David Chinner
2007-11-07 7:15 ` Torsten Kaiser
2007-11-08 0:38 ` David Chinner
2007-11-20 13:16 ` Damien Wyart
2007-11-20 21:09 ` David Chinner
2007-11-02 1:54 ` Fengguang Wu
2007-11-02 1:54 ` Fengguang Wu
2007-11-02 7:42 ` Torsten Kaiser
2007-11-02 7:52 ` Fengguang Wu
2007-11-02 7:52 ` Fengguang Wu
2007-11-02 17:47 ` Torsten Kaiser
2007-10-23 7:55 ` [PATCH] reiserfs: don't drop PG_dirty when releasing sub-page-sized dirty file Fengguang Wu
2007-10-23 7:55 ` Fengguang Wu
2007-10-23 10:07 ` Peter Zijlstra
2007-10-23 11:56 ` Fengguang Wu
2007-10-23 11:56 ` Fengguang Wu
2007-10-23 14:10 ` Chris Mason
2007-10-23 14:40 ` Fengguang Wu
2007-10-23 14:40 ` Fengguang Wu
2007-10-23 10:17 ` Maxim Levitsky
2007-10-23 14:41 ` Fengguang Wu
2007-10-23 14:41 ` Fengguang Wu
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