From: Chris Mason <chris.mason@oracle.com>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>,
Valdis.Kletnieks@vt.edu, josef@redhat.com,
Michael Monnerie <michael.monnerie@is.it-management.at>,
Christoph Hellwig <hch@infradead.org>,
linux-raid@vger.kernel.org, xfs@oss.sgi.com,
linux-kernel@vger.kernel.org, dm-devel@redhat.com
Subject: Re: direct-io regression [Was: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs]
Date: Thu, 5 Aug 2010 15:01:38 -0400 [thread overview]
Message-ID: <20100805190138.GV29846@think> (raw)
In-Reply-To: <x49tyn8c2ea.fsf@segfault.boston.devel.redhat.com>
On Thu, Aug 05, 2010 at 02:58:37PM -0400, Jeff Moyer wrote:
> Chris Mason <chris.mason@oracle.com> writes:
>
> > But, I'm surprised your drive is doing 8K dio reads at 16MB/s, that
> > seems a little high.
>
> I'm not sure why you think that. We're talking about a plain old SATA
> disk, right? I can get 40-50MB/s on my systems for 8KB O_DIRECT reads.
> What am I missing?
Clearly I'm wrong, his drive is going much faster ;) I expect the
smaller reads to be slower but the drive's internal cache is doing well.
-chris
prev parent reply other threads:[~2010-08-05 19:01 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-04 7:35 How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs Dominik Brodowski
2010-08-04 8:50 ` Christoph Hellwig
2010-08-04 9:13 ` Dominik Brodowski
2010-08-04 9:21 ` Christoph Hellwig
2010-08-04 9:16 ` Michael Monnerie
2010-08-04 10:25 ` Dominik Brodowski
2010-08-04 11:18 ` Christoph Hellwig
2010-08-04 11:24 ` Dominik Brodowski
2010-08-04 11:53 ` Mikael Abrahamsson
2010-08-04 12:56 ` Mike Snitzer
2010-08-04 22:24 ` Neil Brown
[not found] ` <20100804111803.GA32643__39273.3621680692$1280923964$gmane$org@infradead.org>
2010-08-04 17:43 ` Andi Kleen
2010-08-04 20:33 ` Valdis.Kletnieks
2010-08-05 9:31 ` direct-io regression [Was: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs] Dominik Brodowski
2010-08-05 11:32 ` Chris Mason
2010-08-05 12:36 ` Josef Bacik
2010-08-05 15:35 ` Dominik Brodowski
2010-08-05 15:39 ` Chris Mason
2010-08-05 15:53 ` Dominik Brodowski
2010-08-05 16:35 ` Dominik Brodowski
2010-08-05 20:47 ` Performance impact of CONFIG_DEBUG? direct-io test case Dominik Brodowski
2010-08-05 20:54 ` Performance impact of CONFIG_SCHED_MC? " Dominik Brodowski
2010-08-05 18:58 ` direct-io regression [Was: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs] Jeff Moyer
2010-08-05 19:01 ` Chris Mason [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=20100805190138.GV29846@think \
--to=chris.mason@oracle.com \
--cc=Valdis.Kletnieks@vt.edu \
--cc=dm-devel@redhat.com \
--cc=hch@infradead.org \
--cc=jmoyer@redhat.com \
--cc=josef@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=linux@dominikbrodowski.net \
--cc=michael.monnerie@is.it-management.at \
--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).