1 files changed, 26 insertions, 4 deletions

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 7f60097d443a..73961f35fdc8 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -141,8 +141,16 @@ static void clocksource_watchdog(unsigned long data)
         }
 
         if (!list_empty(&watchdog_list)) {
-                __mod_timer(&watchdog_timer,
-                            watchdog_timer.expires + WATCHDOG_INTERVAL);
+                /*
+                 * Cycle through CPUs to check if the CPUs stay
+                 * synchronized to each other.
+                 */
+                int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map);
+
+                if (next_cpu >= NR_CPUS)
+                        next_cpu = first_cpu(cpu_online_map);
+                watchdog_timer.expires += WATCHDOG_INTERVAL;
+                add_timer_on(&watchdog_timer, next_cpu);
         }
         spin_unlock(&watchdog_lock);
 }
@@ -164,7 +172,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                 if (!started && watchdog) {
                         watchdog_last = watchdog->read();
                         watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-                        add_timer(&watchdog_timer);
+                        add_timer_on(&watchdog_timer,
+                                     first_cpu(cpu_online_map));
                 }
         } else {
                 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -185,7 +194,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                                 watchdog_last = watchdog->read();
                                 watchdog_timer.expires =
                                         jiffies + WATCHDOG_INTERVAL;
-                                add_timer(&watchdog_timer);
+                                add_timer_on(&watchdog_timer,
+                                             first_cpu(cpu_online_map));
                         }
                 }
         }
@@ -222,6 +232,18 @@ void clocksource_resume(void)
 }
 
 /**
+ * clocksource_touch_watchdog - Update watchdog
+ *
+ * Update the watchdog after exception contexts such as kgdb so as not
+ * to incorrectly trip the watchdog.
+ *
+ */
+void clocksource_touch_watchdog(void)
+{
+        clocksource_resume_watchdog();
+}
+
+/**
  * clocksource_get_next - Returns the selected clocksource
  *
  */