From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 19 Feb 2007 18:12:05 +0000 (+0000)
Subject: [PATCH] NOHZ: Produce debug output instead of a BUG()
X-Git-Tag: v2.6.21-rc1~61
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc5393a6c9c0e70b4b43fb2fb63e3315e9a15c8f;p=linux-2.6

[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 9234e44fc9..512a4a9064 100644
--- 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();
 	/*