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

[Robert Love]

On Thu, 2002-04-04 at 17:42, Linus Torvalds wrote:

> My current tree says
> 
> 	asmlinkage void preempt_schedule(void)
> 	{
> 	        if (unlikely(preempt_get_count()))
> 	                return;
> 	        if (current->state != TASK_RUNNING)
> 	                return;
> 	        schedule();
> 	}

You need to do the same thing in entry.S ... Ingo decoupled the two
entry paths from each other (entry.S does preempt_schedule's work on its
own, and then directly calls schedule).

So, right now the ret_from_intr path sets the task state to
TASK_RUNNING.  That needs to be replaced with a jump out if it is NOT
task running.

Curiously, what is wrong with the way we did it in the original patch? 
I.e. set a bit in preempt_count and use that to skip to pick_next_task
in schedule.  This allows us to preempt any task of any state ...

	Robert Love