[PATCH] NOHZ: Produce debug output instead of a BUG()

The BUG_ON() in tick_nohz_stop_sched_tick() triggers on some boxen.
Remove the BUG_ON and print information about the pending softirq
to allow better debugging of the problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9234e44fc94a8b43a205ba77da11d17fa8321877..512a4a906467e1d0e5a08c00d7d3a83cbc8b69f0 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -165,7 +165,9 @@ void tick_nohz_stop_sched_tick(void)
                goto end;
 
        cpu = smp_processor_id();
-       BUG_ON(local_softirq_pending());
+       if (unlikely(local_softirq_pending()))
+               printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+                      local_softirq_pending());
 
        now = ktime_get();
        /*