* Kamalesh Babulal <[EMAIL PROTECTED]> wrote:
> The CONFIG_NO_HZ is not set and the system seems not be truly locked
> up ,btw wc -l of the softlockup messages is around 108 times, while
> running the libhugetlbfs only and this is reproducible with the
> 2.6.24-git7 also.
Peter just fixed a handful of bugs in this area - does the patch below
help?
Ingo
------------------>
Subject: debug: softlockup looping fix
From: Peter Zijlstra <[EMAIL PROTECTED]>
Rafael J. Wysocki reported weird, multi-seconds delays during
suspend/resume and bisected it back to:
commit 82a1fcb90287052aabfa235e7ffc693ea003fe69
Author: Ingo Molnar <[EMAIL PROTECTED]>
Date: Fri Jan 25 21:08:02 2008 +0100
softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks
fix it:
- restore the old wakeup mechanism
- fix break usage in do_each_thread() { } while_each_thread().
- fix the hotplug switch stmt, a fall-through case was broken.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
---
kernel/softlockup.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
Index: linux/kernel/softlockup.c
===================================================================
--- linux.orig/kernel/softlockup.c
+++ linux/kernel/softlockup.c
@@ -101,6 +101,10 @@ void softlockup_tick(void)
now = get_timestamp(this_cpu);
+ /* 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 delays: */
if (now <= (touch_timestamp + softlockup_thresh))
return;
@@ -191,11 +195,11 @@ static void check_hung_uninterruptible_t
read_lock(&tasklist_lock);
do_each_thread(g, t) {
if (!--max_count)
- break;
+ goto unlock;
if (t->state & TASK_UNINTERRUPTIBLE)
check_hung_task(t, now);
} while_each_thread(g, t);
-
+ unlock:
read_unlock(&tasklist_lock);
}
@@ -218,14 +222,19 @@ 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();
+
+ if (kthread_should_stop())
+ break;
if (this_cpu != check_cpu)
continue;
if (sysctl_hung_task_timeout_secs)
check_hung_uninterruptible_tasks(this_cpu);
+
}
return 0;
@@ -259,13 +268,6 @@ cpu_callback(struct notifier_block *nfb,
wake_up_process(per_cpu(watchdog_task, hotcpu));
break;
#ifdef CONFIG_HOTPLUG_CPU
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- if (!per_cpu(watchdog_task, hotcpu))
- break;
- /* Unbind so it can run. Fall thru. */
- kthread_bind(per_cpu(watchdog_task, hotcpu),
- any_online_cpu(cpu_online_map));
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
if (hotcpu == check_cpu) {
@@ -275,6 +277,14 @@ cpu_callback(struct notifier_block *nfb,
check_cpu = any_online_cpu(temp_cpu_online_map);
}
break;
+
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ if (!per_cpu(watchdog_task, hotcpu))
+ break;
+ /* Unbind so it can run. Fall thru. */
+ kthread_bind(per_cpu(watchdog_task, hotcpu),
+ any_online_cpu(cpu_online_map));
case CPU_DEAD:
case CPU_DEAD_FROZEN:
p = per_cpu(watchdog_task, hotcpu);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
