Re: broken suspend (sched related) [Was: 2.6.24-rc4-mm1]

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> thanks for tracking it down. Does the patch below help?

oops, that should be the patch below. Otherwise the watchdog kernel 
threads will just loop around.

	Ingo

---
 kernel/softlockup.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Index: linux/kernel/softlockup.c
===================================================================
--- linux.orig/kernel/softlockup.c
+++ linux/kernel/softlockup.c
@@ -101,7 +101,11 @@ void softlockup_tick(void)
 
 	now = get_timestamp(this_cpu);
 
-	/* Warn about unreasonable delays: */
+	/* Wake up the high-prio watchdog task every second: */
+	if (now > (touch_timestamp + 1))
+		wake_up_process(per_cpu(watchdog_task, this_cpu));
+
+	/* Warn about unreasonable 10+ seconds delays: */
 	if (now <= (touch_timestamp + softlockup_thresh))
 		return;
 
@@ -213,8 +217,9 @@ static int watchdog(void *__bind_cpu)
 	 * debug-printout triggers in softlockup_tick().
 	 */
 	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
 		touch_softlockup_watchdog();
-		msleep_interruptible(10000);
+		schedule();
 
 		/*
 		 * Only do the hung-tasks check on one CPU: