Subject: Re: i/o scheduling (was Re: NEW_BUFQ_STRATEGY)
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
From: Daniel Carosone <dan@geek.com.au>
List: tech-perform
Date: 12/15/2003 16:37:07
On Sun, Dec 14, 2003 at 12:41:58PM +0900, YAMAMOTO Takashi wrote:
> three queues are for
> [...]
> 	- time non sensitive requests.
> 		e.g. delayed writes

Something that's been discussed before, but is worth mentioning again
at this point - I'd just love to see a mechanism that allowed
really-not-very-interesting requests (the canonical example being
atime updates) to wait ~forever if the disk is not spun up, and then
to proceed when some other higher-priority request wakes up the disk
(or there are too many such waiting?)

That needs some help from the layers above, and probably below.

--
Dan.