[PATCH] NOHZ: Fix RCU handling

When a CPU is needed for RCU the tick has to continue even when it was
stopped before.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 95e41f7f850b..9234e44fc94a 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -191,19 +191,19 @@ void tick_nohz_stop_sched_tick(void)
         next_jiffies = get_next_timer_interrupt(last_jiffies);
         delta_jiffies = next_jiffies - last_jiffies;
 
+        if (rcu_needs_cpu(cpu))
+                delta_jiffies = 1;
         /*
          * Do not stop the tick, if we are only one off
          * or if the cpu is required for rcu
          */
-        if (!ts->tick_stopped && (delta_jiffies == 1 || rcu_needs_cpu(cpu)))
+        if (!ts->tick_stopped && delta_jiffies == 1)
                 goto out;
 
         /* Schedule the tick, if we are at least one jiffie off */
         if ((long)delta_jiffies >= 1) {
 
-                if (rcu_needs_cpu(cpu))
-                        delta_jiffies = 1;
-                else
+                if (delta_jiffies > 1)
                         cpu_set(cpu, nohz_cpu_mask);
                 /*
                  * nohz_stop_sched_tick can be called several times before