xfs: remove nr_to_write writeback windup.

[safe/jmp/linux-2.6] / kernel / mutex.c

diff --git a/kernel/mutex.c b/kernel/mutex.c
index e2d25e9..4c0b7b3 100644 (file)
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -89,7 +89,7 @@ __mutex_lock_slowpath(atomic_t *lock_count);
  *
  * This function is similar to (but not equivalent to) down().
  */
-void inline __sched mutex_lock(struct mutex *lock)
+void __sched mutex_lock(struct mutex *lock)
 {
        might_sleep();
        /*
@@ -148,8 +148,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 
        preempt_disable();
        mutex_acquire(&lock->dep_map, subclass, 0, ip);
-#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES) && \
-    !defined(CONFIG_HAVE_DEFAULT_NO_SPIN_MUTEXES)
+
+#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
        /*
         * Optimistic spinning.
         *
@@ -172,6 +172,13 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                struct thread_info *owner;
 
                /*
+                * If we own the BKL, then don't spin. The owner of
+                * the mutex might be waiting on us to release the BKL.
+                */
+               if (unlikely(current->lock_depth >= 0))
+                       break;
+
+               /*
                 * If there's an owner, wait for it to either
                 * release the lock or go to sleep.
                 */
@@ -249,7 +256,9 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 
                /* didnt get the lock, go to sleep: */
                spin_unlock_mutex(&lock->wait_lock, flags);
-               __schedule();
+               preempt_enable_no_resched();
+               schedule();
+               preempt_disable();
                spin_lock_mutex(&lock->wait_lock, flags);
        }