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-rw-r--r--lib/rwsem-spinlock.c23
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;

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