On 05/20/2016 11:00 AM, Davidlohr Bueso wrote:
On Fri, 20 May 2016, Peter Zijlstra wrote:
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
Similarly, and I know you hate it, but afaict, then semantically
queued_spin_is_contended() ought to be:
- return atomic_read(&lock->val) & ~_Q_LOCKED_MASK;
+ return atomic_read(&lock->val);
Thanks,
Davidlohr
Looking for contended lock, you need to consider the lock waiters also.
So looking at the whole word is right.
Cheers,
Longman
