Re: [patch V3 7/7] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

[Steven Rostedt]

On Tue, 10 Jun 2014 19:41:39 +0200 (CEST)
Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

 
> > On the loop back around, have something like:
> > 
> > 	if (top_waiter) {
> > 		if (!task_has_pi_waiters(task))
> > 			goto out_unlock_pi;
> 
> 	The task has at least one pi waiter.
>  
> > 		if (!requeue &&
> > 		    top_waiter != task_top_pi_waiter(task)) {
> > 			if (!detect_deadlock)
> > 				goto out_unlock_pi;
> > 			else
> > 				requeue = false;
> > 		}
> 
> 	Errm? if requeue is off we are in deadlock detection chainwalk
> 	mode. So all we care about is whether task is blocked on
> 	next_lock or not.

Actually that was a typo on my part. That should have been:

	if (requeue &&
		...

As we don't need to read the task_top_pi_waiter() again.

-- Steve

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/