---

yaml
---
r: 255022
b: refs/heads/master
c: c5d753a
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 10f39bb1b2c1923ca73e70cb13aeee0e9b822d8f
+refs/heads/master: c5d753a55ac92e09816d410cd17093813f1a904b

trunk/kernel/sched.c

@@ -2544,13 +2544,9 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
 }
 
 #ifdef CONFIG_SMP
-static void sched_ttwu_pending(void)
+static void sched_ttwu_do_pending(struct task_struct *list)
 {
 	struct rq *rq = this_rq();
-	struct task_struct *list = xchg(&rq->wake_list, NULL);
-
-	if (!list)
-		return;
 
 	raw_spin_lock(&rq->lock);
 
@@ -2563,9 +2559,45 @@ static void sched_ttwu_pending(void)
 	raw_spin_unlock(&rq->lock);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void sched_ttwu_pending(void)
+{
+	struct rq *rq = this_rq();
+	struct task_struct *list = xchg(&rq->wake_list, NULL);
+
+	if (!list)
+		return;
+
+	sched_ttwu_do_pending(list);
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
 void scheduler_ipi(void)
 {
-	sched_ttwu_pending();
+	struct rq *rq = this_rq();
+	struct task_struct *list = xchg(&rq->wake_list, NULL);
+
+	if (!list)
+		return;
+
+	/*
+	 * Not all reschedule IPI handlers call irq_enter/irq_exit, since
+	 * traditionally all their work was done from the interrupt return
+	 * path. Now that we actually do some work, we need to make sure
+	 * we do call them.
+	 *
+	 * Some archs already do call them, luckily irq_enter/exit nest
+	 * properly.
+	 *
+	 * Arguably we should visit all archs and update all handlers,
+	 * however a fair share of IPIs are still resched only so this would
+	 * somewhat pessimize the simple resched case.
+	 */
+	irq_enter();
+	sched_ttwu_do_pending(list);
+	irq_exit();
 }
 
 static void ttwu_queue_remote(struct task_struct *p, int cpu)