Merge branch '2.6.25.y' into testing

2 files changed, 36 insertions, 5 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2727f9238359..6d8de051382b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1722,7 +1722,12 @@ void cgroup_enable_task_cg_lists(void)
 	use_task_css_set_links = 1;
 	do_each_thread(g, p) {
 		task_lock(p);
-		if (list_empty(&p->cg_list))
+		/*
+		 * We should check if the process is exiting, otherwise
+		 * it will race with cgroup_exit() in that the list
+		 * entry won't be deleted though the process has exited.
+		 */
+		if (!(p->flags & PF_EXITING) && list_empty(&p->cg_list))
 			list_add(&p->cg_list, &p->cgroups->tasks);
 		task_unlock(p);
 	} while_each_thread(g, p);
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 98bee013f71f..c15a359ea611 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -590,7 +590,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 			list_add_tail(&timer->cb_entry,
 				      &base->cpu_base->cb_pending);
 			timer->state = HRTIMER_STATE_PENDING;
-			raise_softirq(HRTIMER_SOFTIRQ);
 			return 1;
 		default:
 			BUG();
@@ -633,6 +632,11 @@ static int hrtimer_switch_to_hres(void)
 	return 1;
 }
 
+static inline void hrtimer_raise_softirq(void)
+{
+	raise_softirq(HRTIMER_SOFTIRQ);
+}
+
 #else
 
 static inline int hrtimer_hres_active(void) { return 0; }
@@ -651,6 +655,7 @@ static inline int hrtimer_reprogram(struct hrtimer *timer,
 {
 	return 0;
 }
+static inline void hrtimer_raise_softirq(void) { }
 
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
@@ -850,7 +855,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
 	struct hrtimer_clock_base *base, *new_base;
 	unsigned long flags;
-	int ret;
+	int ret, raise;
 
 	base = lock_hrtimer_base(timer, &flags);
 
@@ -884,8 +889,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 	enqueue_hrtimer(timer, new_base,
 			new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
 
+	/*
+	 * The timer may be expired and moved to the cb_pending
+	 * list. We can not raise the softirq with base lock held due
+	 * to a possible deadlock with runqueue lock.
+	 */
+	raise = timer->state == HRTIMER_STATE_PENDING;
+
 	unlock_hrtimer_base(timer, &flags);
 
+	if (raise)
+		hrtimer_raise_softirq();
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(hrtimer_start);
@@ -1080,8 +1095,19 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
 			 * If the timer was rearmed on another CPU, reprogram
 			 * the event device.
 			 */
-			if (timer->base->first == &timer->node)
-				hrtimer_reprogram(timer, timer->base);
+			struct hrtimer_clock_base *base = timer->base;
+
+			if (base->first == &timer->node &&
+			    hrtimer_reprogram(timer, base)) {
+				/*
+				 * Timer is expired. Thus move it from tree to
+				 * pending list again.
+				 */
+				__remove_hrtimer(timer, base,
+						 HRTIMER_STATE_PENDING, 0);
+				list_add_tail(&timer->cb_entry,
+					      &base->cpu_base->cb_pending);
+			}
 		}
 	}
 	spin_unlock_irq(&cpu_base->lock);