On 1/18/24 10:45, Jens Axboe wrote:
Do you read the replies to the emails, from the other thread?
Yes.
> And secondly, this avoids a RMW if it's already set.
From the spinlock implementation (something I looked up before I wrote
my previous reply):
static __always_inline int queued_spin_trylock(struct qspinlock *lock)
{
int val = atomic_read(&lock->val);
if (unlikely(val))
return 0;
return likely(atomic_try_cmpxchg_acquire(&lock->val, &val,
_Q_LOCKED_VAL));
}
I think this implementation does not perform a RMW if the spinlock is
already locked.
Thanks,
Bart.
