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Subject: Re: [PATCH] BUG(): sched.c: Line 944
From: Robert Love <rml@tech9.net>
To: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@transmeta.com>, linux-kernel@vger.kernel.org
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Date: 17 Sep 2002 14:47:22 -0400
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On Tue, 2002-09-17 at 12:26, Ingo Molnar wrote:

> On Tue, 17 Sep 2002, Linus Torvalds wrote:
> 
> > On the other hand, we do have other ways to test the preempt count
> > inside the scheduler. In particular, we might just move the
> > "in_atomic()" check a few lines downwards, at which point we've released
> > the kernel lock and explicitly disabled preemption, so at that point the
> > test should be even simpler with fewer conditionals..
> 
> indeed ...

OK so do we want to do (a):

(moved down to after the preempt_disable() and release_kernel_lock())

if (likely(current->state != TASK_ZOMBIE)
	if (unlikely((preempt_count() & ~PREEMPT_ACTIVE) != 1))
		...

or go with (b) where we split schedule() into schedule(),
exit_schedule(), and do_schedule().

	Robert Love


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