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Date: Wed, 10 Jul 2002 21:30:37 +0200 (CEST)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: Ingo Molnar <mingo@elte.hu>
To: Erich Focht <efocht@ess.nec.de>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
       linux-ia64 <linux-ia64@linuxia64.org>
Subject: Re: O(1) scheduler "complex" macros
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the best solution might be to just lock the 'next' task - this needs a new
per-task irq-safe spinlock, to avoid deadlocks. This way whenever a task
is in the middle of a context-switch it cannot be scheduled on another
CPU.

in fact this solution simplifies things - only two per-arch macros are
needed. I've done this in my current 2.5.25 tree:

	http://redhat.com/~mingo/O(1)-scheduler/sched-2.5.25-A4

check out the sparc64 changes for the 'complex' locking scenario - it's
untested, please give it a go on ia64, does that solve your problems? x86
is tested and works just fine.

	Ingo

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