public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jens Axboe <jaxboe@fusionio.com>
To: Shaohua Li <shaohua.li@intel.com>
Cc: "teravest@google.com" <teravest@google.com>,
	lkml <linux-kernel@vger.kernel.org>,
	"Shi, Alex" <alex.shi@intel.com>
Subject: Re: cfq-iosched: a regression
Date: Fri, 19 Aug 2011 08:33:57 +0200	[thread overview]
Message-ID: <4E4E03D5.40404@fusionio.com> (raw)
In-Reply-To: <1313462826.27321.22.camel@sli10-conroe>

On 2011-08-16 04:47, Shaohua Li wrote:
> We have a kernel build regression since 3.1-rc1, which is about 10%
> regression. The kernel source is in an ext3 filesystem.
> Alex Shi bisect it to commit:
> commit a07405b7802691d29ab3b23bdc76ee6d006aad0b
> Author: Justin TerAvest <teravest@google.com>
> Date:   Sun Jul 10 22:09:19 2011 +0200
> 
>     cfq: Remove special treatment for metadata rqs.
> 
> Apparently this is caused by lack metadata preemption, where ext3/ext4
> do use READ_META. I didn't see a way to fix the issue, so suggest
> reverting the patch.
> 
> Reported-by: Alex Shi<alex.shi@intel.com>
> Reported-by: Shaohua Li<shaohua.li@intel.com>

I had a gut feeling on that meta data, it's hard to know exactly where
it helps at this point. I'll revert the commit and then we can diagnose
this on the side.

-- 
Jens Axboe


      parent reply	other threads:[~2011-08-19  6:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-16  2:47 cfq-iosched: a regression Shaohua Li
2011-08-18 20:22 ` Justin TerAvest
2011-08-19  0:21   ` Shaohua Li
2011-08-19  6:33 ` Jens Axboe [this message]

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=4E4E03D5.40404@fusionio.com \
    --to=jaxboe@fusionio.com \
    --cc=alex.shi@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=shaohua.li@intel.com \
    --cc=teravest@google.com \
    /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