From: Jens Axboe <axboe@suse.de>
To: Daniel Pittman <daniel@rimspace.net>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] deadline io scheduler
Date: Thu, 26 Sep 2002 10:29:25 +0200 [thread overview]
Message-ID: <20020926082925.GK12862@suse.de> (raw)
In-Reply-To: <87k7l95f5a.fsf@enki.rimspace.net>
On Thu, Sep 26 2002, Daniel Pittman wrote:
> On Thu, 26 Sep 2002, Jens Axboe wrote:
> > On Wed, Sep 25 2002, Andrew Morton wrote:
>
> [...]
>
> > writes_starved. This controls how many times reads get preferred over
> > writes. The default is 2, which means that we can serve two batches of
> > reads over one write batch. A value of 4 would mean that reads could
> > skip ahead of writes 4 times. A value of 1 would give you 1:1
> > read:write, ie no read preference. A silly value of 0 would give you
> > write preference, always.
>
> Actually, a value of zero doesn't sound completely silly to me, right
> now, since I have been doing a lot of thinking about video capture
> recently.
>
> How much is it going to hurt a filesystem like ext[23] if that value is
> set to zero while doing large streaming writes -- something like
> (almost) uncompressed video at ten to twenty meg a second, for
> gigabytes?
You are going to stalll all reads indefinately :-)
> This is a situation where, for a dedicated machine, delaying reads
> almost forever is actually a valuable thing. At least, valuable until it
> stops the writes from being able to proceed.
Well 0 should achieve that quite fine
--
Jens Axboe
next prev parent reply other threads:[~2002-09-26 8:24 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-25 17:20 [PATCH] deadline io scheduler Jens Axboe
2002-09-26 6:15 ` Andrew Morton
2002-09-26 6:27 ` David S. Miller
2002-09-26 6:44 ` Jens Axboe
2002-09-26 6:59 ` Jens Axboe
2002-09-26 7:06 ` William Lee Irwin III
2002-09-26 7:06 ` David S. Miller
2002-09-26 7:16 ` Jeff Garzik
2002-09-26 7:13 ` David S. Miller
2002-09-26 7:33 ` Jeff Garzik
2002-09-26 7:35 ` David S. Miller
2002-09-26 8:15 ` Michael Clark
2002-09-26 8:18 ` William Lee Irwin III
2002-09-26 17:41 ` Mike Anderson
2002-09-26 18:03 ` Jeff Garzik
2002-09-26 19:21 ` Mike Anderson
2002-09-27 5:41 ` Andrew Vasquez
2002-09-27 5:57 ` Jeff Garzik
2002-09-27 16:58 ` Mike Anderson
2002-09-26 22:41 ` Matt Porter
2002-09-26 22:35 ` Mark Bellon
2002-09-26 20:21 ` Thomas Tonino
2002-09-26 7:41 ` Jeff Garzik
2002-09-26 7:23 ` William Lee Irwin III
2002-09-26 7:11 ` Jeff Garzik
2002-09-26 7:14 ` William Lee Irwin III
2002-09-26 15:54 ` Patrick Mansfield
2002-09-30 8:15 ` Jens Axboe
2002-09-30 15:39 ` Patrick Mansfield
2002-09-30 16:08 ` Jens Axboe
2002-09-26 8:28 ` Daniel Pittman
2002-09-26 8:29 ` Jens Axboe [this message]
2002-09-26 23:23 ` Daniel Pittman
2002-09-30 8:10 ` Jens Axboe
2002-09-26 15:09 ` Rik van Riel
2002-09-26 7:12 ` Andrew Morton
2002-09-26 7:17 ` Jens Axboe
2002-09-26 7:34 ` Jens Axboe
2002-09-30 7:45 ` Pavel Machek
2002-10-02 5:35 ` Jens Axboe
2002-09-27 16:01 Andrew Vasquez
2002-09-27 17:07 ` Mike Anderson
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