From: Tejun Heo <htejun@gmail.com>
To: "François-Julien Marbaud" <fbourget@irisa.fr>
Cc: linux-ide@vger.kernel.org
Subject: Re: Slow perfs with IDE SSD
Date: Thu, 13 Jul 2006 01:21:22 +0900 [thread overview]
Message-ID: <44B52182.3020008@gmail.com> (raw)
In-Reply-To: <loom.20060712T102252-777@post.gmane.org>
François-Julien Marbaud wrote:
> Hi !
>
> I'm doing an internship in a research lab, and we are trying to use a P.ATA SSD
> in order to speed-up a genome computation software.
>
> We got a performance problem, expecially with access time : access time is about
> 800us, and according to the manufacturer it should be about 40us. The bandwith
> is OK.
>
> The SSD is a 2.5' flash hard drive, the slave of the first IDE channel.
>
> We wonder if that could be the because P.ATA driver is not really done for small
> access times, so we got such a poor time. In that case, I guess we would have to
> have a closer look at the driver ...
First of all, try noop elevator.
echo noop > /sys/block/hdx/queue/scheduler
Depending on your workload, adjusting plugging delay/threshold
parameters might help. These are initialized in the kernel source file
block/ll_rw_blk.c::blk_queue_make_request(). q->unplug_thresh and
q->unplug_delay.
--
tejun
next prev parent reply other threads:[~2006-07-12 16:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-12 8:49 Slow perfs with IDE SSD François-Julien Marbaud
2006-07-12 16:21 ` Tejun Heo [this message]
2006-07-12 16:32 ` Tejun Heo
2006-07-13 8:45 ` François-Julien Marbaud
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=44B52182.3020008@gmail.com \
--to=htejun@gmail.com \
--cc=fbourget@irisa.fr \
--cc=linux-ide@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.