Merge branch 'sched/urgent' into timers/urgent

Merging it here because an upcoming timers/urgent fix relies on
a change already in sched/urgent and not yet upstream.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 12 insertions, 6 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5a7c76388731..2127e959e0f4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -443,6 +443,7 @@ struct pacct_struct {
  * @utime:              time spent in user mode, in &cputime_t units
  * @stime:              time spent in kernel mode, in &cputime_t units
  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
+ * @lock:               lock for fields in this struct
  *
  * This structure groups together three kinds of CPU time that are
  * tracked for threads and thread groups.  Most things considering
diff --git a/kernel/sched.c b/kernel/sched.c
index 242d0d47a70d..e1fc67d0674c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3890,19 +3890,24 @@ int select_nohz_load_balancer(int stop_tick)
         int cpu = smp_processor_id();
 
         if (stop_tick) {
-                cpumask_set_cpu(cpu, nohz.cpu_mask);
                 cpu_rq(cpu)->in_nohz_recently = 1;
 
-                /*
-                 * If we are going offline and still the leader, give up!
-                 */
-                if (!cpu_active(cpu) &&
-                    atomic_read(&nohz.load_balancer) == cpu) {
+                if (!cpu_active(cpu)) {
+                        if (atomic_read(&nohz.load_balancer) != cpu)
+                                return 0;
+
+                        /*
+                         * If we are going offline and still the leader,
+                         * give up!
+                         */
                         if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
                                 BUG();
+
                         return 0;
                 }
 
+                cpumask_set_cpu(cpu, nohz.cpu_mask);
+
                 /* time for ilb owner also to sleep */
                 if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
                         if (atomic_read(&nohz.load_balancer) == cpu)