softlockup: fix false positives on CONFIG_NOHZ

David Miller reported soft lockup false-positives that trigger
on NOHZ due to CPUs idling for more than 10 seconds.

The solution is touch the softlockup watchdog when we return from
idle. (by definition we are not 'locked up' when we were idle)

 http://bugzilla.kernel.org/show_bug.cgi?id=9409

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 27a2338deb4ae32d12dd0789a63503666d8e66c1..cb89fa8db110a98df702bbd4bed884d1b45b25dd 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -133,6 +133,8 @@ void tick_nohz_update_jiffies(void)
        if (!ts->tick_stopped)
                return;
 
+       touch_softlockup_watchdog();
+
        cpu_clear(cpu, nohz_cpu_mask);
        now = ktime_get();