From: Carlo Wood <carlo@alinoe.com>
To: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Arjan van de Ven <arjan@infradead.org>,
Jeff Garzik <jeff@garzik.org>,
linux-kernel@vger.kernel.org
Subject: Re: SATA Harddisk speed drop of 100 MB/s
Date: Sat, 23 Jun 2007 04:59:06 +0200 [thread overview]
Message-ID: <20070623025906.GA24336@alinoe.com> (raw)
In-Reply-To: <20070623013132.GA1702@khazad-dum.debian.net>
On Fri, Jun 22, 2007 at 10:31:32PM -0300, Henrique de Moraes Holschuh wrote:
> for i in /sys/block/sd*/queue/scheduler ; do echo -n "scheduler for $i was:" ; cat $i ; echo anticipatory > $i ; done
>
> Should show you the scheduler for all libata/scsi discs, and switch to
> anticipatory. It probably works for hd* as well, but I don't have any
> around to test.
>
> I had ridiculous md raid performance (on resync) using cfq at least once.
> Unfortunately I never bothered trying to track it down, and I didn't check
> the throughput after the resync was done either. Also, I don't recall the
> kernel version, but it was either 2.6.18 or 2.6.20.
Just one kernel version? The problem here is in every
kernel revision after 551c012d7eea3dc5ec063c7ff9c718d39e77634f
2.6.20-rc2,rc3,rc4,rc5,rc6,rc7 ... 2.6.20 ... 2.6.21 ... 2.6.22-rc5
noop:
Timing buffered disk reads: 254 MB in 3.00 seconds = 84.66 MB/sec
anticipatory:
Timing buffered disk reads: 252 MB in 3.02 seconds = 83.43 MB/sec
deadline:
Timing buffered disk reads: 258 MB in 3.02 seconds = 85.41 MB/sec
cfq:
Timing buffered disk reads: 194 MB in 3.03 seconds = 64.06 MB/sec
The normal value is cfq. So, all other schedulars are somewhat faster,
but still far from the correct 165 MB/s.
--
Carlo Wood <carlo@alinoe.com>
next prev parent reply other threads:[~2007-06-23 2:59 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-20 22:48 SATA Harddisk speed drop of 100 MB/s Carlo Wood
2007-06-20 23:06 ` Jeff Garzik
2007-06-21 3:36 ` Arjan van de Ven
2007-06-22 16:21 ` Carlo Wood
2007-06-22 21:17 ` Henrique de Moraes Holschuh
2007-06-22 21:27 ` Carlo Wood
2007-06-23 1:31 ` Henrique de Moraes Holschuh
2007-06-23 2:59 ` Carlo Wood [this message]
2007-06-23 17:29 ` Andrew Morton
2007-06-23 22:21 ` Jeff Garzik
2007-06-25 15:18 ` Lennart Sorensen
2007-06-25 16:04 ` Carlo Wood
2007-06-22 21:44 ` SATA RAID5 " Carlo Wood
2007-06-23 3:54 ` Carlo Wood
2007-06-23 6:22 ` Tejun Heo
2007-06-22 21:48 ` Carlo Wood
2007-06-23 7:03 ` Jeff Garzik
2007-06-23 7:54 ` Tejun Heo
2007-06-23 12:53 ` Carlo Wood
2007-06-23 17:30 ` Bartlomiej Zolnierkiewicz
2007-06-23 22:43 ` Jeff Garzik
2007-06-24 11:58 ` Michael Tokarev
2007-06-24 12:59 ` Dr. David Alan Gilbert
2007-06-24 14:21 ` Justin Piszcz
2007-06-24 15:52 ` Michael Tokarev
2007-06-24 16:59 ` Justin Piszcz
2007-06-24 22:07 ` Carlo Wood
2007-06-24 23:46 ` Mark Lord
2007-06-25 0:23 ` Patrick Mau
2007-06-24 15:48 ` Michael Tokarev
2007-07-05 22:12 ` Phillip Susi
2007-06-23 5:26 SATA Harddisk " Al Boldi
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=20070623025906.GA24336@alinoe.com \
--to=carlo@alinoe.com \
--cc=arjan@infradead.org \
--cc=hmh@hmh.eng.br \
--cc=jeff@garzik.org \
--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 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).