From: Davidlohr Bueso <dave@stgolabs.net>
Date: Tue, 20 Jan 2015 01:39:21 +0000 (-0800)
Subject: locking/mutex: Explicitly mark task as running after wakeup
X-Git-Tag: v4.0-rc1~164^2~4
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=51587bcf31d070119d37de6103543c807f5ccdb3;p=linux.git

locking/mutex: Explicitly mark task as running after wakeup

By the time we wake up and get the lock after being asleep
in the slowpath, we better be running. As good practice,
be explicit about this and avoid any mischief.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1421717961.4903.11.camel@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index c67a60b61625..57407062e209 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -587,6 +587,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		schedule_preempt_disabled();
 		spin_lock_mutex(&lock->wait_lock, flags);
 	}
+	__set_task_state(task, TASK_RUNNING);
+
 	mutex_remove_waiter(lock, &waiter, current_thread_info());
 	/* set it to 0 if there are no waiters left: */
 	if (likely(list_empty(&lock->wait_list)))