Re: [PATCH] fix TASK_STOPPED vs TASK_NONINTERACTIVE interaction

[Linus Torvalds <torvalds@osdl.org>]

On Thu, 29 Sep 2005, Oleg Nesterov wrote:
>
> do_signal_stop:
> 
> 	for_each_thread(t) {
> 		if (t->state < TASK_STOPPED)
> 			++sig->group_stop_count;
> 	}
> 
> However, TASK_NONINTERACTIVE > TASK_STOPPED, so this loop will not
> count TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE threads.

Ok, I think your patch is correct (we really do try to keep an order to 
those task flags), but the _real_ issue is that the comparisons are bogus.

Using ">" for task states is wrong. It's a bitmask, and if you want to 
check multiple states, then we should just do so with

	if (t->state & (TASK_xxx | TASK_yyy | ...))

Oh, well. The inequality comparisons are shorter, and historical, so I 
guess it's debatable whether we should remove them all.

		Linus
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