1 files changed, 21 insertions, 0 deletions

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 338f1d1c1c66..a7bf517b0482 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -54,6 +54,7 @@
 #include <linux/stop_machine.h>
 #include <linux/random.h>
 #include <linux/ftrace_event.h>
+#include <linux/suspend.h>
 
 #include "rcutree.h"
 #include <trace/events/rcu.h>
@@ -3032,6 +3033,25 @@ static int rcu_cpu_notify(struct notifier_block *self,
         return NOTIFY_OK;
 }
 
+static int rcu_pm_notify(struct notifier_block *self,
+                         unsigned long action, void *hcpu)
+{
+        switch (action) {
+        case PM_HIBERNATION_PREPARE:
+        case PM_SUSPEND_PREPARE:
+                if (nr_cpu_ids <= 256) /* Expediting bad for large systems. */
+                        rcu_expedited = 1;
+                break;
+        case PM_POST_HIBERNATION:
+        case PM_POST_SUSPEND:
+                rcu_expedited = 0;
+                break;
+        default:
+                break;
+        }
+        return NOTIFY_OK;
+}
+
 /*
  * Spawn the kthread that handles this RCU flavor's grace periods.
  */
@@ -3273,6 +3293,7 @@ void __init rcu_init(void)
          * or the scheduler are operational.
          */
         cpu_notifier(rcu_cpu_notify, 0);
+        pm_notifier(rcu_pm_notify, 0);
         for_each_online_cpu(cpu)
                 rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
 }