From 2ffa5a5cd2fe792b6399c903d5172adf088d8ff7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 7 Jun 2014 12:10:36 +0200 Subject: [PATCH] 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 Reviewed-by: Steven Rostedt Reviewed-by: Lai Jiangshan --- kernel/locking/rtmutex.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 39c9f8075e14..cd517091fb21 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -463,6 +463,8 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, /* 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 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, 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);