In the slowpath of down for write, we bail out in case of signal received and
try to wake up any pending waiter but it makes no sense to wake up a write
waiter given any lock holder, either write or read.
The RFC is do nothing for wwaiter if any lock holder present - they will fill
their duty at lock release time.
Only for thoughts now.
Hillf
--- x/kernel/locking/rwsem.c
+++ y/kernel/locking/rwsem.c
@@ -418,6 +418,8 @@ static void rwsem_mark_wake(struct rw_se
waiter = rwsem_first_waiter(sem);
if (waiter->type == RWSEM_WAITING_FOR_WRITE) {
+ if (RWSEM_LOCK_MASK & atomic_long_read(&sem->count))
+ return;
if (wake_type == RWSEM_WAKE_ANY) {
/*
* Mark writer at the front of the queue for wakeup.
--
