From: Oliver Neukum <oliver@neukum.org>
To: Con Kolivas <kernel@kolivas.org>, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] O13int for interactivity
Date: Tue, 5 Aug 2003 10:12:12 +0200
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Am Dienstag, 5. August 2003 09:26 schrieb Con Kolivas:
> On Tue, 5 Aug 2003 16:03, Andrew Morton wrote:
> > We do prefer that TASK_UNINTERRUPTIBLE processes are woken promptly so they
> > can submit more IO and go back to sleep.  Remember that we are artificially
> > leaving the disk head idle in the expectation that the task will submit
> > more I/O.  It's pretty sad if the CPU scheduler leaves the anticipated task
> > in the doldrums for five milliseconds.
> 
> Indeed that has been on my mind. This change doesn't affect how long it takes 
> to wake up. It simply prevents tasks from getting full interactive status 
> during the period they are doing unint. sleep.

If you take that to its logical conclusion, such tasks should be woken
immediately. Likewise, the io scheduler should be notified when you know
that the task won't do io or will do other io, like waiting on character
devices, go paging out or terminate.

	Regards
		Oliver

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