From ee7fed540563b27e1028bec0b509921496c91bf9 Mon Sep 17 00:00:00 2001 From: Ulrich Obergfell Date: Thu, 5 Nov 2015 18:44:39 -0800 Subject: [PATCH] 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 Reviewed-by: Aaron Tomlin Acked-by: Don Zickus Cc: Ulrich Obergfell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/watchdog.c | 10 ++++++---- 1 file 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; -- 2.20.1