From: Andrew Morton <akpm@osdl.org>
To: "Igor A. Valcov" <viaprog@gmail.com>
Cc: linux-kernel@vger.kernel.org, xfs@oss.sgi.com
Subject: Re: XFS filesystem performance drop in kernels 2.6.16+
Date: Fri, 10 Nov 2006 22:52:57 -0800 [thread overview]
Message-ID: <20061110225257.63f91851.akpm@osdl.org> (raw)
In-Reply-To: <bde600590611100516u7b8ca1bfs74d3cc8b78eb3520@mail.gmail.com>
On Fri, 10 Nov 2006 16:16:27 +0300
"Igor A. Valcov" <viaprog@gmail.com> wrote:
> Below is a simplified version of the test program,
Boy, I hope not. The results of this test program are of very little interest.
> for (i = 0; i < 262144; i++) {
> /* Write data to a big file */
> write (nFiles [0], buf, __BYTES);
>
> /* Write data to small files */
> for (f = 1; f < __FILES; f++)
> write (nFiles [f], &f, sizeof (f));
> }
This sits in a loop doing write(fd, buf, 4). This is wildly inefficient -
you'd get a 10x throughput benefit and maybe 100x reduction in CPU cost
simply by switching to fwrite().
I suspect something went wrong here.
next prev parent reply other threads:[~2006-11-11 7:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bde600590611090930g3ab97aq3c76d7bca4ec267f@mail.gmail.com>
[not found] ` <1163095715.5632.102.camel@xenon.msp.redhat.com>
2006-11-10 1:10 ` XFS filesystem performance drop in kernels 2.6.16+ David Chinner
2006-11-14 17:32 ` No Mails Shailendra Tripathi
2006-11-14 20:10 ` Eric Sandeen
2006-11-14 20:44 ` Russell Cattelan
2006-11-10 3:36 ` XFS filesystem performance drop in kernels 2.6.16+ Eric Sandeen
2006-11-10 11:59 ` Jan Engelhardt
2006-11-10 13:16 ` Igor A. Valcov
2006-11-10 17:14 ` Eric Sandeen
2006-11-11 6:52 ` Andrew Morton [this message]
2006-11-11 10:55 ` Jan Engelhardt
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=20061110225257.63f91851.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viaprog@gmail.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