From: Martin Knoblauch <knobi@knobisoft.de>
To: Mike Snitzer <snitzer@gmail.com>, Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: 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>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: regression: 100% io-wait with 2.6.24-rcX
Date: Wed, 16 Jan 2008 01:26:41 -0800 (PST) [thread overview]
Message-ID: <76258.29672.qm@web32604.mail.mud.yahoo.com> (raw)
----- Original Message ----
> From: Mike Snitzer <snitzer@gmail.com>
> To: Fengguang Wu <wfg@mail.ustc.edu.cn>
> Cc: 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>; Linus Torvalds <torvalds@linux-foundation.org>; Andrew Morton <akpm@li>
> Sent: Tuesday, January 15, 2008 10:13:22 PM
> Subject: Re: regression: 100% io-wait with 2.6.24-rcX
>
> On Jan 14, 2008 7:50 AM, Fengguang Wu wrote:
> > On Mon, Jan 14, 2008 at 12:41:26PM +0100, Peter Zijlstra wrote:
> > >
> > > On Mon, 2008-01-14 at 12:30 +0100, Joerg Platte wrote:
> > > > Am Montag, 14. Januar 2008 schrieb Fengguang Wu:
> > > >
> > > > > Joerg, this patch fixed the bug for me :-)
> > > >
> > > > Fengguang, congratulations, I can confirm that your patch
> fixed
>
the bug! With
> > > > previous kernels the bug showed up after each reboot. Now,
> when
>
booting the
> > > > patched kernel everything is fine and there is no longer
> any
>
suspicious
> > > > iowait!
> > > >
> > > > Do you have an idea why this problem appeared in 2.6.24?
> Did
>
somebody change
> > > > the ext2 code or is it related to the changes in the scheduler?
> > >
> > > It was Fengguang who changed the inode writeback code, and I
> guess
>
the
> > > new and improved code was less able do deal with these funny corner
> > > cases. But he has been very good in tracking them down and
> solving
>
them,
> > > kudos to him for that work!
> >
> > Thank you.
> >
> > In particular the bug is triggered by the patch named:
> > "writeback: introduce writeback_control.more_io to
> indicate
>
more io"
> > That patch means to speed up writeback, but unfortunately its
> > aggressiveness has disclosed bugs in reiserfs, jfs and now ext2.
> >
> > Linus, given the number of bugs it triggered, I'd recommend revert
> > this patch(git commit
> 2e6883bdf49abd0e7f0d9b6297fc3be7ebb2250b).
>
Let's
> > push it back to -mm tree for more testings?
>
> Fengguang,
>
> I'd like to better understand where your writeback work stands
> relative to 2.6.24-rcX and -mm. To be clear, your changes in
> 2.6.24-rc7 have been benchmarked to provide a ~33% sequential write
> performance improvement with ext3 (as compared to 2.6.22, CFS could be
> helping, etc but...). Very impressive!
>
> Given this improvement it is unfortunate to see your request to revert
> 2e6883bdf49abd0e7f0d9b6297fc3be7ebb2250b but it is understandable if
> you're not confident in it for 2.6.24.
>
> That said, you recently posted an -mm patchset that first reverts
> 2e6883bdf49abd0e7f0d9b6297fc3be7ebb2250b and then goes on to address
> the "slow writes for concurrent large and small file writes" bug:
> http://lkml.org/lkml/2008/1/15/132
>
> For those interested in using your writeback improvements in
> production sooner rather than later (primarily with ext3); what
> recommendations do you have? Just heavily test our own 2.6.24 + your
> evolving "close, but not ready for merge" -mm writeback patchset?
>
Hi Fengguang, Mike,
I can add myself to Mikes question. It would be good to know a "roadmap" for the writeback changes. Testing 2.6.24-rcX so far has been showing quite nice improvement of the overall writeback situation and it would be sad to see this [partially] gone in 2.6.24-final. Linus apparently already has reverted "...2250b". I will definitely repeat my tests with -rc8. and report.
Cheers
Martin
next reply other threads:[~2008-01-16 9:26 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-16 9:26 Martin Knoblauch [this message]
[not found] ` <E1JF6w8-0000vs-HM@localhost.localdomain>
2008-01-16 12:00 ` regression: 100% io-wait with 2.6.24-rcX Fengguang Wu
-- 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
2008-01-18 8:19 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
2008-01-18 20:00 ` Mike Snitzer
2008-01-18 22:47 ` Mike Snitzer
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
2008-01-07 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=76258.29672.qm@web32604.mail.mud.yahoo.com \
--to=knobi@knobisoft.de \
--cc=jplatte@naasa.net \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=snitzer@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=wfg@mail.ustc.edu.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).