Re: Patch: linux-2.5.8-pre1/kernel/exit.c change caused BUG() at

[Linus Torvalds]

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