Subject: rtmutex: Add rtmutex_lock_killable()
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 09 Jun 2011 11:43:52 +0200
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: da77ceac3d20f27310a07a7c346a4ee6b40d6c28
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

Add "killable" type to rtmutex. We need this since rtmutex are used as
"normal" mutexes which do use this type.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 include/linux/rtmutex.h  |    1 +
 kernel/locking/rtmutex.c |   19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -115,6 +115,7 @@ extern void rt_mutex_lock(struct rt_mute
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_timed_lock(struct rt_mutex *lock,
 			       struct hrtimer_sleeper *timeout);
 
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1562,6 +1562,25 @@ int __sched __rt_mutex_futex_trylock(str
 }
 
 /**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock:              the rt_mutex to be locked
+ * @detect_deadlock:   deadlock detection on/off
+ *
+ * Returns:
+ *  0          on success
+ * -EINTR      when interrupted by a signal
+ * -EDEADLK    when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+	might_sleep();
+
+	return rt_mutex_fastlock(lock, TASK_KILLABLE, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
  * rt_mutex_timed_lock - lock a rt_mutex interruptible
  *			the timeout structure is provided
  *			by the caller