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From: Alasdair G Kergon <agk@redhat.com>
To: Martin Knoblauch <spamtrap@knobisoft.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Mel Gorman <mel@csn.ul.ie>, Fengguang Wu <wfg@mail.ustc.edu.cn>,
	Mike Snitzer <snitzer@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	jplatte@naasa.net, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org,
	"linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>,
	James.Bottomley@steeleye.com, Jens Axboe <jens.axboe@oracle.com>,
	Milan Broz <mbroz@redhat.com>, Neil Brown <neilb@suse.de>
Subject: Re: regression: 100% io-wait with 2.6.24-rcX
Date: Tue, 22 Jan 2008 14:39:33 +0000	[thread overview]
Message-ID: <20080122143933.GA11111@agk.fab.redhat.com> (raw)
In-Reply-To: <903015.63912.qm@web32611.mail.mud.yahoo.com>

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.

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
 
Alasdair
-- 
agk@redhat.com

  parent reply	other threads:[~2008-01-22 14:41 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-18  8:19 regression: 100% io-wait with 2.6.24-rcX Martin Knoblauch
2008-01-18 16:01 ` Mel Gorman
2008-01-18 17:46   ` Linus Torvalds
2008-01-18 19:01     ` Martin Knoblauch
2008-01-18 19:23       ` Linus Torvalds
2008-01-22 14:39       ` Alasdair G Kergon [this message]
2008-01-18 20:00     ` Mike Snitzer
2008-01-18 22:47       ` Mike Snitzer
  -- strict thread matches above, loose matches on Subject: below --
2008-01-23 11:12 Martin Knoblauch
2008-01-22 18:51 Martin Knoblauch
2008-01-22 15:25 Martin Knoblauch
2008-01-22 23:40 ` Alasdair G Kergon
2008-01-19 10:24 Martin Knoblauch
2008-01-17 21:50 Martin Knoblauch
2008-01-17 22:12 ` Mel Gorman
2008-01-17 17:51 Martin Knoblauch
2008-01-17 17:44 Martin Knoblauch
2008-01-17 20:23 ` Mel Gorman
2008-01-17 13:52 Martin Knoblauch
2008-01-17 16:11 ` Mike Snitzer
2008-01-16 14:15 Martin Knoblauch
2008-01-16 16:27 ` Mike Snitzer
2008-01-16  9:26 Martin Knoblauch
     [not found] ` <E1JF6w8-0000vs-HM@localhost.localdomain>
2008-01-16 12:00   ` Fengguang Wu
2008-01-07 10:51 Joerg Platte
2008-01-07 11:19 ` Ingo Molnar
2008-01-07 13:24   ` Joerg Platte
2008-01-07 13:32     ` Peter Zijlstra
2008-01-07 13:40       ` Joerg Platte
     [not found]         ` <E1JCRbA-0002bh-3c@localhost.localdomain>
2008-01-09  3:27           ` Fengguang Wu
2008-01-09  6:13             ` Joerg Platte
     [not found]               ` <E1JCZg2-0001DE-RP@localhost.localdomain>
2008-01-09 12:04                 ` Fengguang Wu
2008-01-09 12:22                   ` Joerg Platte
     [not found]                     ` <E1JCaUd-0001Ko-Tt@localhost.localdomain>
2008-01-09 12:57                       ` Fengguang Wu
2008-01-09 13:04                         ` Joerg Platte
     [not found]                           ` <E1JCrMj-0001HR-SZ@localhost.localdomain>
2008-01-10  6:58                             ` Fengguang Wu
     [not found]                           ` <E1JCrsE-0000v4-Dz@localhost.localdomain>
2008-01-10  7:30                             ` Fengguang Wu
     [not found]                           ` <20080110073046.GA3432@mail.ustc.edu.cn>
     [not found]                             ` <E1JCsDr-0002cl-0e@localhost.localdomain>
2008-01-10  7:53                               ` Fengguang Wu
2008-01-10  8:37                                 ` Joerg Platte
     [not found]                                   ` <E1JCt0n-00048n-AD@localhost.localdomain>
2008-01-10  8:43                                     ` Fengguang Wu
2008-01-10 10:03                                       ` Joerg Platte
     [not found]                                         ` <E1JDBk4-0000UF-03@localhost.localdomain>
2008-01-11  4:43                                           ` Fengguang Wu
2008-01-11  5:29                                             ` Joerg Platte
2008-01-11  6:41                                               ` Joerg Platte
2008-01-12 23:32                                             ` Joerg Platte
     [not found]                                               ` <E1JDwaA-00017Q-W6@localhost.localdomain>
2008-01-13  6:44                                                 ` Fengguang Wu
2008-01-13  8:05                                                   ` Joerg Platte
     [not found]                                                     ` <E1JDy5a-0001al-Tk@localhost.localdomain>
2008-01-13  8:21                                                       ` Fengguang Wu
2008-01-13  9:49                                                         ` Joerg Platte
     [not found]                                                           ` <E1JE1Uz-0002w5-6z@localhost.localdomain>
2008-01-13 11:59                                                             ` Fengguang Wu
     [not found]                                                           ` <20080113115933.GA11045@mail.ustc.edu.cn>
     [not found]                                                             ` <E1JEGPH-0001uw-Df@localhost.localdomain>
2008-01-14  3:54                                                               ` Fengguang Wu
     [not found]                                                             ` <20080114035439.GA7330@mail.ustc.edu.cn>
     [not found]                                                               ` <E1JEM2I-00010S-5U@localhost.localdomain>
2008-01-14  9:55                                                                 ` Fengguang Wu
2008-01-14 11:30                                                                   ` Joerg Platte
2008-01-14 11:41                                                                     ` Peter Zijlstra
     [not found]                                                                       ` <E1JEOmD-0001Ap-U7@localhost.localdomain>
2008-01-14 12:50                                                                         ` Fengguang Wu
2008-01-15 21:13                                                                           ` Mike Snitzer
     [not found]                                                                             ` <E1JF0m1-000101-OK@localhost.localdomain>
2008-01-16  5:25                                                                               ` Fengguang Wu
2008-01-15 21:42                                                                         ` Ingo Molnar
     [not found]                                                                           ` <E1JF0bJ-0000zU-FG@localhost.localdomain>
2008-01-16  5:14                                                                             ` Fengguang Wu

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