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authorIngo Molnar <mingo@elte.hu>2011-07-20 20:59:26 +0200
committerIngo Molnar <mingo@elte.hu>2011-07-20 20:59:26 +0200
commitd1e9ae47a0285d3f1699e8219ce50f656243b93f (patch)
tree2f5a68b5ba1677bcd49ee759f09ffc5ccccb1455 /kernel/sched.c
parente6625fa48e6580a74b7e700efd7e6463e282810b (diff)
parenta841796f11c90d53dbac773be56b04fbee8af272 (diff)
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/urgent
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c44
1 files changed, 38 insertions, 6 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 3dc716f6d8a..31e92aee624 100644
--- 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)