From: Rusty Russell <rusty@rustcorp.com.au>
To: "Fernando Luis Vázquez Cao" <fernando@oss.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>, linux-kernel@vger.kernel.org
Subject: Re: request->ioprio
Date: Thu, 7 Aug 2008 06:33:05 +1000 [thread overview]
Message-ID: <200808070633.06112.rusty@rustcorp.com.au> (raw)
In-Reply-To: <1218014196.4419.44.camel@sebastian.kern.oss.ntt.co.jp>
On Wednesday 06 August 2008 19:16:36 Fernando Luis Vázquez Cao wrote:
> Hi Jens, Rusty,
Hi Fernando,
> Trying to implement i/o tracking all the way up to the page cache (so
> that cfq and the future cgroup-based I/O controllers can schedule
> buffered I/O properly) I noticed that struct request's ioprio is
> initialized but never used for I/O scheduling purposes. Indeed there
> seems to be one single user of this member: virtio_blk.
Hey, do I win a prize? :)
> Virtio uses
> struct request's ioprio in the request() function of the virtio block
> driver, which just copies the ioprio value to the output header of
> virtblk_req.
Yes, we pass it through to the host, in the assumption they might want to use
it to schedule our I/Os relative to each other.
I'm a little surprised noone else uses it, but I'm sure they will...
Rusty.
next parent reply other threads:[~2008-08-08 6:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1218014196.4419.44.camel@sebastian.kern.oss.ntt.co.jp>
2008-08-06 20:33 ` Rusty Russell [this message]
2008-08-13 7:06 ` request->ioprio Fernando Luis Vázquez Cao
2008-08-13 8:14 ` [PATCH] virtio_blk: use a wrapper function to access io context information of IO requests Fernando Luis Vázquez Cao
2008-08-14 4:42 ` Rusty Russell
2008-08-14 5:17 ` Fernando Luis Vázquez Cao
2008-08-14 5:22 ` Fernando Luis Vázquez Cao
2008-08-14 7:58 ` Jens Axboe
2008-08-14 2:16 ` request->ioprio Rusty Russell
2008-08-14 4:26 ` request->ioprio Fernando Luis Vázquez Cao
2008-08-15 5:51 ` request->ioprio Fernando Luis Vázquez Cao
2008-08-16 7:13 ` request->ioprio Rusty Russell
2008-08-06 9:32 request->ioprio Fernando Luis Vázquez Cao
2008-08-06 17:22 ` request->ioprio Divyesh Shah
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