From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 28 Nov 2007 14:52:56 +0000 (+0100)
Subject: softlockup: fix false positives on CONFIG_NOHZ
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=d3938204468dccae16be0099a2abf53db4ed0505;p=deliverable%2Flinux.git

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 27a2338deb4a..cb89fa8db110 100644
--- 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();