watchdog: Respect watchdog cpumask on CPU hotplug

The rework of the watchdog core to use cpu_stop_work broke the watchdog
cpumask on CPU hotplug.

The watchdog_enable/disable() functions are now called unconditionally from
the hotplug callback, i.e. even on CPUs which are not in the watchdog
cpumask. As a consequence the watchdog can become unstoppable.

Only invoke them when the plugged CPU is in the watchdog cpumask.

Fixes: 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u" threads with cpu_stop_work")
Reported-by: Maxime Coquelin <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Maxime Coquelin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Ricardo Neri <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
This commit is contained in:
Thomas Gleixner 2019-03-26 22:51:02 +01:00
commit 7dd4761711

View file

@ -554,13 +554,15 @@ static void softlockup_start_all(void)
int lockup_detector_online_cpu(unsigned int cpu)
{
watchdog_enable(cpu);
if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
watchdog_enable(cpu);
return 0;
}
int lockup_detector_offline_cpu(unsigned int cpu)
{
watchdog_disable(cpu);
if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
watchdog_disable(cpu);
return 0;
}