From: Jens Axboe <jens.axboe@oracle.com>
To: Steve Rottinger <steve@pentek.com>
Cc: Leon Woestenberg <leon.woestenberg@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: splice methods in character device driver
Date: Tue, 16 Jun 2009 20:28:10 +0200 [thread overview]
Message-ID: <20090616182810.GD11363@kernel.dk> (raw)
In-Reply-To: <4A37B4D8.5090404@pentek.com>
On Tue, Jun 16 2009, Steve Rottinger wrote:
> >> I'm doing about 300MB/s to my hardware RAID, running two instances of my
> >> splice() copy application
> >> (One on each RAID channel). I would like to combine the two RAID
> >> channels using a software RAID 0;
> >> however, splice, even from /dev/zero runs horribly slow to a software
> >> RAID device. I'd be curious
> >> to know if anyone else has tried this?
> >>
> >
> > Did you trace it and find out why it was slow? It should not be. Moving
> > 300MB/sec should not be making any machine sweat.
> >
> I haven't dug into this too deeply, yet; however, I did discover
> something interesting: The splice runs much faster using the software
> raid, if I transfer to a file on a mounted filesystem, instead of the
> raw md block device.
OK, that's a least a starting point. I'll try this tomorrow (raw block
device vs fs file).
--
Jens Axboe
next prev parent reply other threads:[~2009-06-16 18:28 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-11 14:40 splice methods in character device driver Steve Rottinger
2009-05-11 19:22 ` Jens Axboe
2009-05-13 16:59 ` Steve Rottinger
2009-06-03 21:32 ` Leon Woestenberg
2009-06-04 7:32 ` Jens Axboe
2009-06-04 13:20 ` Steve Rottinger
2009-06-12 19:21 ` Leon Woestenberg
2009-06-12 19:59 ` Jens Axboe
2009-06-12 20:45 ` Steve Rottinger
2009-06-16 11:59 ` Jens Axboe
2009-06-16 15:06 ` Steve Rottinger
2009-06-16 18:24 ` [RFC][PATCH] add support for shrinking/growing a pipe (Was "Re: splice methods in character device driver") Jens Axboe
2009-06-16 18:28 ` Jens Axboe [this message]
2009-06-06 21:25 ` splice methods in character device driver Leon Woestenberg
2009-06-08 7:05 ` Jens Axboe
2009-06-12 22:05 ` Leon Woestenberg
2009-06-13 7:26 ` Jens Axboe
2009-06-13 20:04 ` Leon Woestenberg
2009-06-16 11:57 ` Jens Axboe
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=20090616182810.GD11363@kernel.dk \
--to=jens.axboe@oracle.com \
--cc=leon.woestenberg@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=steve@pentek.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