Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 14168c4..fde6ff9 100644 (file)
--- a/kernel/sched.c
+++ b/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)