cgroups: add cpu_relax() calls in css_tryget() and cgroup_clear_css_refs()

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

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 4ab17da..69d9cb9 100644 (file)
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -17,12 +17,6 @@
 
 #include "rtmutex_common.h"
 
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-# include "rtmutex-debug.h"
-#else
-# include "rtmutex.h"
-#endif
-
 /*
  * lock->owner state tracking:
  *
@@ -191,7 +185,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
                        prev_max = max_lock_depth;
                        printk(KERN_WARNING "Maximum lock depth %d reached "
                               "task: %s (%d)\n", max_lock_depth,
-                              top_task->comm, top_task->pid);
+                              top_task->comm, task_pid_nr(top_task));
                }
                put_task_struct(task);
 
@@ -212,6 +206,19 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
        if (!waiter || !waiter->task)
                goto out_unlock_pi;
 
+       /*
+        * Check the orig_waiter state. After we dropped the locks,
+        * the previous owner of the lock might have released the lock
+        * and made us the pending owner:
+        */
+       if (orig_waiter && !orig_waiter->task)
+               goto out_unlock_pi;
+
+       /*
+        * Drop out, when the task has no waiters. Note,
+        * top_waiter can be NULL, when we are in the deboosting
+        * mode!
+        */
        if (top_waiter && (!task_has_pi_waiters(task) ||
                           top_waiter != task_top_pi_waiter(task)))
                goto out_unlock_pi;
@@ -623,9 +630,11 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
        set_current_state(state);
 
        /* Setup the timer, when timeout != NULL */
-       if (unlikely(timeout))
-               hrtimer_start(&timeout->timer, timeout->timer.expires,
-                             HRTIMER_ABS);
+       if (unlikely(timeout)) {
+               hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+               if (!hrtimer_active(&timeout->timer))
+                       timeout->task = NULL;
+       }
 
        for (;;) {
                /* Try to acquire the lock: */
@@ -659,9 +668,16 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
                         * all over without going into schedule to try
                         * to get the lock now:
                         */
-                       if (unlikely(!waiter.task))
+                       if (unlikely(!waiter.task)) {
+                               /*
+                                * Reset the return value. We might
+                                * have returned with -EDEADLK and the
+                                * owner released the lock while we
+                                * were walking the pi chain.
+                                */
+                               ret = 0;
                                continue;
-
+                       }
                        if (unlikely(ret))
                                break;
                }