3 files changed, 19 insertions, 2 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index d464bd0d6578..6312521df2c1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -226,6 +226,7 @@ extern void scheduler_tick(void);
 extern void softlockup_tick(void);
 extern void spawn_softlockup_task(void);
 extern void touch_softlockup_watchdog(void);
+extern void touch_all_softlockup_watchdogs(void);
 #else
 static inline void softlockup_tick(void)
 {
@@ -236,6 +237,9 @@ static inline void spawn_softlockup_task(void)
 static inline void touch_softlockup_watchdog(void)
 {
 }
+static inline void touch_all_softlockup_watchdogs(void)
+{
+}
 #endif
 
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 0227f1625a75..5530ed211f72 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4750,6 +4750,8 @@ void show_state_filter(unsigned long state_filter)
                         show_task(p);
         } while_each_thread(g, p);
 
+        touch_all_softlockup_watchdogs();
+
         read_unlock(&tasklist_lock);
         /*
          * Only show locks if all tasks are dumped:
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 5ea631742dbc..8fa7040247ad 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -50,6 +50,16 @@ void touch_softlockup_watchdog(void)
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
+void touch_all_softlockup_watchdogs(void)
+{
+        int cpu;
+
+        /* Cause each CPU to re-update its timestamp rather than complain */
+        for_each_online_cpu(cpu)
+                per_cpu(touch_timestamp, cpu) = 0;
+}
+EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
+
 /*
  * This callback runs from the timer interrupt, and checks
  * whether the watchdog thread has hung or not:
@@ -61,9 +71,10 @@ void softlockup_tick(void)
         unsigned long print_timestamp;
         unsigned long now;
 
-        /* watchdog task hasn't updated timestamp yet */
-        if (touch_timestamp == 0)
+        if (touch_timestamp == 0) {
+                touch_softlockup_watchdog();
                 return;
+        }
 
         print_timestamp = per_cpu(print_timestamp, this_cpu);