From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Martin Boutin <martboutin@gmail.com>,
"Kernel.org-Linux-RAID" <linux-raid@vger.kernel.org>,
Eric Sandeen <sandeen@redhat.com>,
"Kernel.org-Linux-EXT4" <linux-ext4@vger.kernel.org>,
xfs-oss <xfs@oss.sgi.com>
Subject: Re: Filesystem writes on RAID5 too slow
Date: Fri, 22 Nov 2013 01:21:36 -0800 [thread overview]
Message-ID: <20131122092136.GD32568@infradead.org> (raw)
In-Reply-To: <20131121234116.GD6502@dastard>
> From: Dave Chinner <dchinner@redhat.com>
>
> The function xfs_bmap_isaeof() is used to indicate that an
> allocation is occurring at or past the end of file, and as such
> should be aligned to the underlying storage geometry if possible.
>
> Commit 27a3f8f ("xfs: introduce xfs_bmap_last_extent") changed the
> behaviour of this function for empty files - it turned off
> allocation alignment for this case accidentally. Hence large initial
> allocations from direct IO are not getting correctly aligned to the
> underlying geometry, and that is cause write performance to drop in
> alignment sensitive configurations.
>
> Fix it by considering allocation into empty files as requiring
> aligned allocation again.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
Ooops. The fix looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
Might be worth cooking up a test for this, scsi_debug can expose
geometry, and we already have it wired to to large sector size
testing in xfstests.
next prev parent reply other threads:[~2013-11-22 9:21 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-18 16:02 Filesystem writes on RAID5 too slow Martin Boutin
2013-11-18 18:28 ` Eric Sandeen
2013-11-19 0:57 ` Dave Chinner
2013-11-21 9:11 ` Martin Boutin
2013-11-21 9:26 ` Dave Chinner
2013-11-21 9:50 ` Martin Boutin
2013-11-21 13:31 ` Martin Boutin
2013-11-21 16:35 ` Martin Boutin
2013-11-21 23:41 ` Dave Chinner
2013-11-22 9:21 ` Christoph Hellwig [this message]
2013-11-22 22:40 ` Dave Chinner
2013-11-23 8:41 ` Christoph Hellwig
2013-11-24 23:21 ` Dave Chinner
2013-11-22 13:33 ` Martin Boutin
2013-12-10 19:18 ` Christoph Hellwig
2013-12-11 0:27 ` Dave Chinner
2013-12-11 19:09 ` Ben Myers
2013-11-18 18:41 ` Roman Mamedov
2013-11-18 19:25 ` Roman Mamedov
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=20131122092136.GD32568@infradead.org \
--to=hch@infradead.org \
--cc=david@fromorbit.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=martboutin@gmail.com \
--cc=sandeen@redhat.com \
--cc=xfs@oss.sgi.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;
as well as URLs for NNTP newsgroup(s).