---

yaml
---
r: 288649
b: refs/heads/master
c: 86f5e6a
h: refs/heads/master
i:
  288647: 4c3f44a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5f329089431aac08bf759fa2bcb34077a6aa1f4e
+refs/heads/master: 86f5e6a7b192721995ece919985ac75222402351

trunk/kernel/watchdog.c

@@ -3,12 +3,9 @@
  *
  * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
  *
- * this code detects hard lockups: incidents in where on a CPU
- * the kernel does not respond to anything except NMI.
- *
- * Note: Most of this code is borrowed heavily from softlockup.c,
- * so thanks to Ingo for the initial implementation.
- * Some chunks also taken from arch/x86/kernel/apic/nmi.c, thanks
+ * Note: Most of this code is borrowed heavily from the original softlockup
+ * detector, so thanks to Ingo for the initial implementation.
+ * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
  * to those contributors as well.
  */
 
@@ -117,9 +114,10 @@ static unsigned long get_sample_period(void)
 {
 	/*
 	 * convert watchdog_thresh from seconds to ns
-	 * the divide by 5 is to give hrtimer 5 chances to
-	 * increment before the hardlockup detector generates
-	 * a warning
+	 * the divide by 5 is to give hrtimer several chances (two
+	 * or three with the current relation between the soft
+	 * and hard thresholds) to increment before the
+	 * hardlockup detector generates a warning
 	 */
 	return get_softlockup_thresh() * (NSEC_PER_SEC / 5);
 }
@@ -336,9 +334,11 @@ static int watchdog(void *unused)
 
 	set_current_state(TASK_INTERRUPTIBLE);
 	/*
-	 * Run briefly once per second to reset the softlockup timestamp.
-	 * If this gets delayed for more than 60 seconds then the
-	 * debug-printout triggers in watchdog_timer_fn().
+	 * Run briefly (kicked by the hrtimer callback function) once every
+	 * get_sample_period() seconds (4 seconds by default) to reset the
+	 * softlockup timestamp. If this gets delayed for more than
+	 * 2*watchdog_thresh seconds then the debug-printout triggers in
+	 * watchdog_timer_fn().
 	 */
 	while (!kthread_should_stop()) {
 		__touch_watchdog();