diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-02-02 00:23:08 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-02-02 14:27:45 +1100 |
| commit | ed50d6cbc394cd0966469d3e249353c9dd1d38b9 (patch) | |
| tree | 8df8f5d8b4ce057bf0df7ee2996603fdd18e0e7e /kernel | |
| parent | aa6299926950c8dfe2fea638276cad6def092bc9 (diff) | |
| download | linux-ed50d6cbc394cd0966469d3e249353c9dd1d38b9.tar.bz2 | |
debug: softlockup looping fix
Rafael J. Wysocki reported weird, multi-seconds delays during
suspend/resume and bisected it back to:
commit 82a1fcb90287052aabfa235e7ffc693ea003fe69
Author: Ingo Molnar <mingo@elte.hu>
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.
Bisected-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/softlockup.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/kernel/softlockup.c b/kernel/softlockup.c index c1d76552446e..7c2da88db4ed 100644 --- a/kernel/softlockup.c +++ b/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_tasks(int this_cpu) 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, unsigned long action, void *hcpu) 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, unsigned long action, void *hcpu) 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); |