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Date: Thu, 4 Apr 2002 11:13:19 -0800 (PST)
From: Linus Torvalds <torvalds@transmeta.com>
To: Dave Hansen <haveblue@us.ibm.com>
cc: "Adam J. Richter" <adam@yggdrasil.com>, <linux-kernel@vger.kernel.org>,
        Robert Love <rml@tech9.net>
Subject: Re: Patch: linux-2.5.8-pre1/kernel/exit.c change caused BUG() at
 boot time
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On Thu, 4 Apr 2002, Dave Hansen wrote:
>
> I've diabled preemption in the area where it used to be disabled because 
> of the old lock_kernel().  I'm sending this message from a machine with 
> that patch applied, so the patch does fix it.

I think the real fix is to make sure that preemption never hits while 
current->state == TASK_ZOMBIE.

In other words, I think the _correct_ fix is to just make 
preempt_schedule() check for something like

	if (current->state != TASK_RUNNING)
		return;

and just getting rid of the current "unconditionally set state to
running".

(Side note: if the state isn't running, we're most likely going to
reschedule in a controlled manner soon anyway. Sure, there are some loops 
which set state to non-runnable early for race avoidance, but is it a 
_problem_?)

		Linus

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