summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorUlrich Obergfell <uobergfe@redhat.com>2015-11-05 18:44:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-05 19:34:48 -0800
commitee7fed540563b27e1028bec0b509921496c91bf9 (patch)
treed58ef0a0559d3b99c321b7f3f7454fe0e7c7fce5
parentc993590c6ae6273681d9fb2a8d26dce03bf9d96c (diff)
watchdog: do not unpark threads in watchdog_park_threads() on error
If kthread_park() returns an error, watchdog_park_threads() should not blindly 'roll back' the already parked threads to the unparked state. Instead leave it up to the callers to handle such errors appropriately in their context. For example, it is redundant to unpark the threads if the lockup detectors will soon be disabled by the callers anyway. Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/watchdog.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e8b19db9c14a..452e4ed507e5 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -654,6 +654,12 @@ static struct smp_hotplug_thread watchdog_threads = {
/*
* park all watchdog threads that are specified in 'watchdog_cpumask'
+ *
+ * This function returns an error if kthread_park() of a watchdog thread
+ * fails. In this situation, the watchdog threads of some CPUs can already
+ * be parked and the watchdog threads of other CPUs can still be runnable.
+ * Callers are expected to handle this special condition as appropriate in
+ * their context.
*/
static int watchdog_park_threads(void)
{
@@ -665,10 +671,6 @@ static int watchdog_park_threads(void)
if (ret)
break;
}
- if (ret) {
- for_each_watchdog_cpu(cpu)
- kthread_unpark(per_cpu(softlockup_watchdog, cpu));
- }
put_online_cpus();
return ret;