From: Jens Axboe <axboe@suse.de>
To: Eduard Hasenleithner <eduardh@aon.at>, linux-kernel@vger.kernel.org
Subject: Re: DVD blockdevice buffers
Date: Fri, 18 May 2001 21:25:31 +0200 [thread overview]
Message-ID: <20010518212531.A6763@suse.de> (raw)
In-Reply-To: <20010518210226.A7147@moserv.hasi>
In-Reply-To: <20010518210226.A7147@moserv.hasi>; from eduardh@aon.at on Fri, May 18, 2001 at 09:02:26PM +0200
On Fri, May 18 2001, Eduard Hasenleithner wrote:
> I have a problem with the buffering mechanism of my blockdevice,
> namely a ide_scsi DVD-ROM drive. After inserting a DVD and reading
> data linearly from the DVD, an excessive amount of buffer memory gets
> allocated.
>
> This can easily be reproduced with
> cat /dev/sr0 > /dev/null
>
> Remember, nearly the same task is carried out when playing a DVD.
>
> As a result the system performance goes down. I'm still able to use
> my applications, but es every single piece of unused memory is swapped
> out, and swapping in costs a certain amount of time.
That's why streaming media applications like a dvd player should use raw
I/O -- to bypass system cache. See /dev/raw*
--
Jens Axboe
next prev parent reply other threads:[~2001-05-18 19:26 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-05-18 19:02 DVD blockdevice buffers Eduard Hasenleithner
2001-05-18 19:25 ` Jens Axboe [this message]
2001-05-18 19:59 ` Eduard Hasenleithner
2001-05-20 2:36 ` Linus Torvalds
2001-05-23 17:34 ` Stephen C. Tweedie
2001-05-23 18:12 ` Linus Torvalds
2001-05-23 19:57 ` Stephen C. Tweedie
2001-05-23 20:01 ` Linus Torvalds
2001-05-23 20:40 ` Jeff Garzik
2001-05-23 22:32 ` Andrea Arcangeli
2001-05-25 20:12 ` blkdev-pagecache-2 [was Re: DVD blockdevice buffers] Andrea Arcangeli
2001-05-25 20:15 ` Andrea Arcangeli
2001-05-23 22:09 ` DVD blockdevice buffers Andrea Arcangeli
2001-05-23 22:13 ` Alexander Viro
2001-05-23 22:24 ` Andrea Arcangeli
2001-05-24 11:36 ` Stephen C. Tweedie
2001-05-25 15:09 ` Eric W. Biederman
2001-05-25 15:45 ` Stephen C. Tweedie
2001-05-25 17:16 ` Linus Torvalds
2001-05-25 17:40 ` Alexander Viro
2001-05-25 18:05 ` Linus Torvalds
2001-05-25 18:24 ` Alexander Viro
2001-05-25 19:02 ` Stephen C. Tweedie
2001-05-27 6:38 ` Pavel Machek
2001-05-25 21:07 ` Eric W. Biederman
2001-05-25 21:18 ` Linus Torvalds
2001-05-25 22:31 ` Eric W. Biederman
-- strict thread matches above, loose matches on Subject: below --
2001-05-19 18:16 Adam Schrotenboer
2001-05-19 22:56 ` Jens Axboe
2001-05-20 1:55 ` Adam Schrotenboer
2001-05-21 15:44 ` Adam Schrotenboer
2001-05-21 15:47 ` Jens Axboe
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