Call specific smt functions only if smt siblings are detected at boot.

-ck

---
 kernel/sched/bfs.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Index: linux-4.7-ck4/kernel/sched/bfs.c
===================================================================
--- linux-4.7-ck4.orig/kernel/sched/bfs.c	2016-09-13 17:21:52.117252643 +1000
+++ linux-4.7-ck4/kernel/sched/bfs.c	2016-09-13 17:21:52.115252688 +1000
@@ -7144,6 +7144,9 @@ void __init sched_init_smp(void)
 {
 	struct sched_domain *sd;
 	int cpu, other_cpu;
+#ifdef CONFIG_SCHED_SMT
+	bool smt_threads = false;
+#endif
 
 	cpumask_var_t non_isolated_cpus;
 
@@ -7216,13 +7219,16 @@ void __init sched_init_smp(void)
 			cpumask_copy(&rq->thread_mask, thread_cpumask(cpu));
 			cpumask_clear_cpu(cpu, &rq->thread_mask);
 			rq->siblings_idle = siblings_cpu_idle;
+			smt_threads = true;
 		}
 #endif
 	}
 #ifdef CONFIG_SMT_NICE
-	check_siblings = &check_smt_siblings;
-	wake_siblings = &wake_smt_siblings;
-	smt_schedule = &smt_should_schedule;
+	if (smt_threads) {
+		check_siblings = &check_smt_siblings;
+		wake_siblings = &wake_smt_siblings;
+		smt_schedule = &smt_should_schedule;
+	}
 #endif
 	grq_unlock_irq();
 	mutex_unlock(&sched_domains_mutex);