[PATCH] pi-futex: futex_lock_pi/futex_unlock_pi support

This adds the actual pi-futex implementation, based on rt-mutexes.

[dino@in.ibm.com: fix an oops-causing race]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h
index e068024eeffc..9c75856e791e 100644
--- a/kernel/rtmutex_common.h
+++ b/kernel/rtmutex_common.h
@@ -112,4 +112,12 @@ static inline unsigned long rt_mutex_owner_pending(struct rt_mutex *lock)
         return (unsigned long)lock->owner & RT_MUTEX_OWNER_PENDING;
 }
 
+/*
+ * PI-futex support (proxy locking functions, etc.):
+ */
+extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
+extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
+                                       struct task_struct *proxy_owner);
+extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
+                                  struct task_struct *proxy_owner);
 #endif