From: William Lee Irwin III <wli@holomorphy.com>
To: "Mr. Berkley Shands" <berkley@dssimail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Severe I/O performance regression 2.6.6 to 2.6.7 or 2.6.8-rc3
Date: Thu, 5 Aug 2004 10:25:31 -0700 [thread overview]
Message-ID: <20040805172531.GC17188@holomorphy.com> (raw)
In-Reply-To: <41126811.7020607@dssimail.com>
On Thu, Aug 05, 2004 at 12:02:09PM -0500, Mr. Berkley Shands wrote:
> Two severe disk read bugs:
> In a nutshell (see attached for gory details). Moving from 2.6.6 to
> 2.6.7 dropped multi-threaded RAID0
> read performance from 429MB/Sec to 81MB/Sec. Single threaded reads
> improved 368MB/Sec to 418MB/Sec.
> The code in drivers/md has no effect on this problem. Clearly this is a
> thread access issue. Redhat ES3.0
> on x86_64 or i686. The underlying hardware is capable of 955MB/Sec disk
> reads off 28 drives,
> 541MB/Sec off 14 drives. Tuning I/O block size (11KB to 239KB) and
> BLKRASET size (448 to 1024 or more)
> helps a little. System idle goes from 0% to 50% (2.6.6 to 2.6.8-rc3).
By any chance could you do binary search on the bk snapshots between
2.6.6 and 2.6.7?
-- wli
next prev parent reply other threads:[~2004-08-05 17:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-05 17:02 Severe I/O performance regression 2.6.6 to 2.6.7 or 2.6.8-rc3 Mr. Berkley Shands
2004-08-05 17:25 ` William Lee Irwin III [this message]
2004-08-05 19:58 ` Mr. Berkley Shands
2004-08-05 20:46 ` William Lee Irwin III
2004-08-05 22:33 ` Marcelo Tosatti
2004-08-06 0:21 ` William Lee Irwin III
2004-08-06 2:09 ` Andy Isaacson
2004-08-06 2:27 ` William Lee Irwin III
2004-08-06 2:42 ` Andy Isaacson
2004-08-06 3:11 ` William Lee Irwin III
2004-08-06 8:33 ` Helge Hafting
2004-08-06 8:51 ` William Lee Irwin III
2004-08-06 18:02 ` Fast patch for " Mr. Berkley Shands
2004-08-08 8:22 ` Ram Pai
2004-08-16 20:30 ` [PATCH] " Ram Pai
-- strict thread matches above, loose matches on Subject: below --
2004-08-06 0:41 Berkley Shands
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=20040805172531.GC17188@holomorphy.com \
--to=wli@holomorphy.com \
--cc=berkley@dssimail.com \
--cc=linux-kernel@vger.kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.