rtmutex: No need to keep task ref for lock owner check
There is no point to keep the task ref across the check for lock
owner. Drop the ref before that, so the protection context is clear.
Found while documenting the chain walk.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 39c9f807..cd517091 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -463,6 +463,8 @@
/* Release the task */
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ put_task_struct(task);
+
if (!rt_mutex_owner(lock)) {
/*
* If the requeue above changed the top waiter, then we need
@@ -472,9 +474,8 @@
if (top_waiter != rt_mutex_top_waiter(lock))
wake_up_process(rt_mutex_top_waiter(lock)->task);
raw_spin_unlock(&lock->wait_lock);
- goto out_put_task;
+ return 0;
}
- put_task_struct(task);
/* Grab the next task */
task = rt_mutex_owner(lock);