Re: sem_lock() vs qspinlocks

[Peter Zijlstra]

On Thu, May 19, 2016 at 10:39:26PM -0700, Davidlohr Bueso wrote:
>  In addition, this makes me wonder if queued_spin_is_locked() should then be:
> 
> -     return atomic_read(&lock->val);
> +     return atomic_read(&lock->val) & _Q_LOCKED_MASK;
> 
> And avoid considering pending waiters as locked.

Probably