NOHZ: Rate limit the local softirq pending warning output

The warning in the NOHZ code, which triggers when a CPU goes idle with
softirqs pending can fill up the logs quite quickly.  Rate limit the output
until we found the root cause of that problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3483e6cb9549..3e7ebc4646b7 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -167,9 +167,15 @@ void tick_nohz_stop_sched_tick(void)
                 goto end;
 
         cpu = smp_processor_id();
-        if (unlikely(local_softirq_pending()))
-                printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
-                       local_softirq_pending());
+        if (unlikely(local_softirq_pending())) {
+                static int ratelimit;
+
+                if (ratelimit < 10) {
+                        printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+                               local_softirq_pending());
+                        ratelimit++;
+                }
+        }
 
         now = ktime_get();
         /*