From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Thu, 11 Dec 2008 16:04:11 +0000 (+0100)
Subject: nohz: no softirq pending warnings for offline cpus
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fa116ea35ec7f40e890972324409e99eed008d56;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

nohz: no softirq pending warnings for offline cpus

Impact: remove false positive warning

After a cpu was taken down during cpu hotplug (read: disabled for interrupts)
it still might have pending softirqs. However take_cpu_down makes sure
that the idle task will run next instead of ksoftirqd on the taken down cpu.
The idle task will call tick_nohz_stop_sched_tick which might warn about
pending softirqs just before the cpu kills itself completely.

However the pending softirqs on the dead cpu aren't a problem because they
will be moved to an online cpu during CPU_DEAD handling.

So make sure we warn only for online cpus.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 342fc9ccab46..dc17ffcf1919 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -247,7 +247,7 @@ void tick_nohz_stop_sched_tick(int inidle)
 	if (need_resched())
 		goto end;
 
-	if (unlikely(local_softirq_pending())) {
+	if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
 		static int ratelimit;
 
 		if (ratelimit < 10) {