if v == locked {
			if atomic.Casuintptr(&l.key, locked, 0) {
				break
			}
		} else {
			// Other M's are waiting for the lock.
			// Dequeue an M.
			mp = muintptr(v &^ locked).ptr()
			if atomic.Casuintptr(&l.key, v, uintptr(mp.nextwaitm)) {
				// Dequeued an M.  Wake it.
				semawakeup(mp)
				break
			}
		}
	}
	gp.m.mLockProfile.recordUnlock(l)
	gp.m.locks--
	if gp.m.locks < 0 {