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Date: Fri, 11 Jan 2002 01:01:22 +0100 (CET)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: <mingo@elte.hu>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: <linux-kernel@vger.kernel.org>, Mike Kravetz <kravetz@us.ibm.com>,
        Anton Blanchard <anton@samba.org>, george anzinger <george@mvista.com>,
        Davide Libenzi <davidel@xmailserver.org>,
        Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [patch] O(1) scheduler, -G1, 2.5.2-pre10, 2.4.17 (fwd)
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On Thu, 10 Jan 2002, Linus Torvalds wrote:

> Don't try to make the timer code know stuff that the timer code should
> not and does not know about. Just call the scheduler on each tick, and
> let the scheduler make its decision.

agreed, the -H4 patch implements this cleanup:

    http://redhat.com/~mingo/O(1)-scheduler/sched-O1-2.5.2-pre11-H4.patch

the timer code calls the scheduler_tick() function once per local timer
interrupt. This function then decides whether the current task is idle or
not. (this should also fix the timeslice-expiration bug of any possibly
pid 0 process.)

(there is one small ugliness left, the function also has to be prepared
for a not yet complete scheduler state, rq->idle == NULL and rq->curr ==
NULL. I'll fix this later, it's a detail.)

(-H4 has been sanity-compiled & booted on SMP.)

other changes since -H1:

 - removed dead code from wakeup.

	Ingo

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