On Thu, 8 Sep 2016, Sebastian Andrzej Siewior wrote:
> + if (parent == dentry) {
> + /* the task with the highest priority won't schedule */
> + r = cond_resched();
> + if (!r && (rt_task(current) || dl_task(current)))
That's wrong because a non RT task will just spin until its time slice is
up. Wasted cycles for nothing.
Ideally we make spinning conditional on
!on_cpu(dentry->lock->owner)
That would avoid going to sleep if the owner runs on another cpu. We have
no mechanism for that, but I think it'd be worth to think about one.
> + cpu_chill();
> + } else
> + dentry = parent;
Missing braces
Thanks,
tglx
