On Sat, Apr 13, 2019 at 01:22:54PM -0400, Waiman Long wrote: > @@ -549,7 +582,7 @@ static noinline enum owner_state > rwsem_spin_on_owner(struct rw_semaphore *sem) > return !owner ? OWNER_NULL : OWNER_READER; > } > > -static bool rwsem_optimistic_spin(struct rw_semaphore *sem) > +static bool rwsem_optimistic_spin(struct rw_semaphore *sem, bool wlock) > { > bool taken = false; > bool is_rt_task = rt_task(current); > @@ -558,9 +591,6 @@ static bool rwsem_optimistic_spin(struct rw_semaphore > *sem) > preempt_disable(); > > /* sem->wait_lock should not be held when doing optimistic spinning */ > - if (!rwsem_can_spin_on_owner(sem)) > - goto done; > - > if (!osq_lock(&sem->osq)) > goto done; > > @@ -580,10 +610,11 @@ static bool rwsem_optimistic_spin(struct rw_semaphore > *sem) > /* > * Try to acquire the lock > */ > - if (rwsem_try_write_lock_unqueued(sem)) { > - taken = true; > + taken = wlock ? rwsem_try_write_lock_unqueued(sem) > + : rwsem_try_read_lock_unqueued(sem); > + > + if (taken) > break; > - } > > /* > * An RT task cannot do optimistic spinning if it cannot
Alternatively you pass the trylock function as an argument: static bool rwsem_optimistic_spin(struct rw_semaphore *sem, bool (*trylock)(struct rw_semaphore *sem)) { ... if (trylock(sem)) { taken = true; goto unlock; } ... }