diff options
Diffstat (limited to 'lib/rwsem-spinlock.c')
-rw-r--r-- | lib/rwsem-spinlock.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index 5f117f37ac0a..9be8a9144978 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c @@ -70,26 +70,17 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); - if (!wakewrite) { - if (waiter->type == RWSEM_WAITING_FOR_WRITE) - goto out; - goto dont_wake_writers; - } - - /* - * as we support write lock stealing, we can't set sem->activity - * to -1 here to indicate we get the lock. Instead, we wake it up - * to let it go get it again. - */ if (waiter->type == RWSEM_WAITING_FOR_WRITE) { - wake_up_process(waiter->task); + if (wakewrite) + /* Wake up a writer. Note that we do not grant it the + * lock - it will have to acquire it when it runs. */ + wake_up_process(waiter->task); goto out; } /* grant an infinite number of read locks to the front of the queue */ - dont_wake_writers: woken = 0; - while (waiter->type == RWSEM_WAITING_FOR_READ) { + do { struct list_head *next = waiter->list.next; list_del(&waiter->list); @@ -99,10 +90,10 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) wake_up_process(tsk); put_task_struct(tsk); woken++; - if (list_empty(&sem->wait_list)) + if (next == &sem->wait_list) break; waiter = list_entry(next, struct rwsem_waiter, list); - } + } while (waiter->type != RWSEM_WAITING_FOR_WRITE); sem->activity += woken; |