diff options
Diffstat (limited to 'kernel/locking/rwsem-spinlock.c')
| -rw-r--r-- | kernel/locking/rwsem-spinlock.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c index 2c93571162cb..3a5048572065 100644 --- a/kernel/locking/rwsem-spinlock.c +++ b/kernel/locking/rwsem-spinlock.c @@ -85,6 +85,13 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) list_del(&waiter->list); tsk = waiter->task; + /* + * Make sure we do not wakeup the next reader before + * setting the nil condition to grant the next reader; + * otherwise we could miss the wakeup on the other + * side and end up sleeping again. See the pairing + * in rwsem_down_read_failed(). + */ smp_mb(); waiter->task = NULL; wake_up_process(tsk); @@ -154,7 +161,7 @@ void __sched __down_read(struct rw_semaphore *sem) set_task_state(tsk, TASK_UNINTERRUPTIBLE); } - tsk->state = TASK_RUNNING; + __set_task_state(tsk, TASK_RUNNING); out: ; } |