The locality code was not correctly picking up the relationships between CPUs properly.
Fix it and display locality in dmesg.

Fix for PID namespace leakage in BFS scheduler courtesy of Bogdan Trach

-ck

---
 kernel/sched/bfs.c       |   80 ++++++++++++++++++++++-------------------------
 kernel/sched/bfs_sched.h |    2 -
 2 files changed, 38 insertions(+), 44 deletions(-)

Index: linux-3.15-ck1/kernel/sched/bfs.c
===================================================================
--- linux-3.15-ck1.orig/kernel/sched/bfs.c	2014-07-03 22:45:12.000000000 +0300
+++ linux-3.15-ck1/kernel/sched/bfs.c	2014-07-03 23:13:25.558679430 +0300
@@ -125,7 +125,7 @@
 
 void print_scheduler_version(void)
 {
-	printk(KERN_INFO "BFS CPU scheduler v0.448 by Con Kolivas.\n");
+	printk(KERN_INFO "BFS CPU scheduler v0.449 by Con Kolivas.\n");
 }
 
 /*
@@ -1915,7 +1915,7 @@
 	preempt_enable();
 #endif
 	if (current->set_child_tid)
-		put_user(current->pid, current->set_child_tid);
+		put_user(task_pid_vnr(current), current->set_child_tid);
 }
 
 /*
@@ -6677,19 +6677,25 @@
 }
 #endif
 #ifdef CONFIG_SCHED_SMT
+static const cpumask_t *thread_cpumask(int cpu)
+{
+	return topology_thread_cpumask(cpu);
+}
 /* All this CPU's SMT siblings are idle */
 static bool siblings_cpu_idle(int cpu)
 {
-	return cpumask_subset(&(cpu_rq(cpu)->smt_siblings),
-			      &grq.cpu_idle_map);
+	return cpumask_subset(thread_cpumask(cpu), &grq.cpu_idle_map);
 }
 #endif
 #ifdef CONFIG_SCHED_MC
+static const cpumask_t *core_cpumask(int cpu)
+{
+	return topology_core_cpumask(cpu);
+}
 /* All this CPU's shared cache siblings are idle */
 static bool cache_cpu_idle(int cpu)
 {
-	return cpumask_subset(&(cpu_rq(cpu)->cache_siblings),
-			      &grq.cpu_idle_map);
+	return cpumask_subset(core_cpumask(cpu), &grq.cpu_idle_map);
 }
 #endif
 
@@ -6707,7 +6713,7 @@
 void __init sched_init_smp(void)
 {
 	struct sched_domain *sd;
-	int cpu;
+	int cpu, other_cpu;
 
 	cpumask_var_t non_isolated_cpus;
 
@@ -6749,33 +6755,14 @@
 	for_each_online_cpu(cpu) {
 		struct rq *rq = cpu_rq(cpu);
 
+		/* First check if this cpu is in the same node */
 		for_each_domain(cpu, sd) {
-			int locality, other_cpu;
-
-#ifdef CONFIG_SCHED_SMT
-			if (sd->level == SD_LV_SIBLING) {
-				for_each_cpu_mask(other_cpu, *sched_domain_span(sd))
-					cpumask_set_cpu(other_cpu, &rq->smt_siblings);
-			}
-#endif
-#ifdef CONFIG_SCHED_MC
-			if (sd->level == SD_LV_MC) {
-				for_each_cpu_mask(other_cpu, *sched_domain_span(sd))
-					cpumask_set_cpu(other_cpu, &rq->cache_siblings);
-			}
-#endif
-			if (sd->level <= SD_LV_SIBLING)
-				locality = 1;
-			else if (sd->level <= SD_LV_MC)
-				locality = 2;
-			else if (sd->level <= SD_LV_NODE)
-				locality = 3;
-			else
+			if (sd->level > SD_LV_NODE)
 				continue;
-
+			/* Set locality to local node if not already found lower */
 			for_each_cpu_mask(other_cpu, *sched_domain_span(sd)) {
-				if (locality < rq->cpu_locality[other_cpu])
-					rq->cpu_locality[other_cpu] = locality;
+				if (rq->cpu_locality[other_cpu] > 3)
+					rq->cpu_locality[other_cpu] = 3;
 			}
 		}
 
@@ -6783,17 +6770,32 @@
 		 * Each runqueue has its own function in case it doesn't have
 		 * siblings of its own allowing mixed topologies.
 		 */
-#ifdef CONFIG_SCHED_SMT
-		if (cpus_weight(rq->smt_siblings) > 1)
-			rq->siblings_idle = siblings_cpu_idle;
-#endif
 #ifdef CONFIG_SCHED_MC
-		if (cpus_weight(rq->cache_siblings) > 1)
+		for_each_cpu_mask(other_cpu, *core_cpumask(cpu)) {
+			if (rq->cpu_locality[other_cpu] > 2)
+				rq->cpu_locality[other_cpu] = 2;
+		}
+		if (cpus_weight(*core_cpumask(cpu)) > 1)
 			rq->cache_idle = cache_cpu_idle;
 #endif
+#ifdef CONFIG_SCHED_SMT
+		for_each_cpu_mask(other_cpu, *thread_cpumask(cpu))
+			rq->cpu_locality[other_cpu] = 1;
+		if (cpus_weight(*thread_cpumask(cpu)) > 1)
+			rq->siblings_idle = siblings_cpu_idle;
+#endif
 	}
 	grq_unlock_irq();
 	mutex_unlock(&sched_domains_mutex);
+
+	for_each_online_cpu(cpu) {
+		struct rq *rq = cpu_rq(cpu);
+		for_each_online_cpu(other_cpu) {
+			if (other_cpu <= cpu)
+				continue;
+			printk(KERN_WARNING "LOCALITY CPU %d to %d: %d\n", cpu, other_cpu, rq->cpu_locality[other_cpu]);
+		}
+	}
 }
 #else
 void __init sched_init_smp(void)
@@ -6862,16 +6864,10 @@
 
 		rq = cpu_rq(i);
 #ifdef CONFIG_SCHED_SMT
-		cpumask_clear(&rq->smt_siblings);
-		cpumask_set_cpu(i, &rq->smt_siblings);
 		rq->siblings_idle = sole_cpu_idle;
-		cpumask_set_cpu(i, &rq->smt_siblings);
 #endif
 #ifdef CONFIG_SCHED_MC
-		cpumask_clear(&rq->cache_siblings);
-		cpumask_set_cpu(i, &rq->cache_siblings);
 		rq->cache_idle = sole_cpu_idle;
-		cpumask_set_cpu(i, &rq->cache_siblings);
 #endif
 		rq->cpu_locality = kmalloc(nr_cpu_ids * sizeof(int *), GFP_ATOMIC);
 		for_each_possible_cpu(j) {
Index: linux-3.15-ck1/kernel/sched/bfs_sched.h
===================================================================
--- linux-3.15-ck1.orig/kernel/sched/bfs_sched.h	2014-07-03 22:45:12.000000000 +0300
+++ linux-3.15-ck1/kernel/sched/bfs_sched.h	2014-07-03 22:46:06.181697659 +0300
@@ -37,12 +37,10 @@
 #ifdef CONFIG_SCHED_SMT
 	bool (*siblings_idle)(int cpu);
 	/* See if all smt siblings are idle */
-	cpumask_t smt_siblings;
 #endif /* CONFIG_SCHED_SMT */
 #ifdef CONFIG_SCHED_MC
 	bool (*cache_idle)(int cpu);
 	/* See if all cache siblings are idle */
-	cpumask_t cache_siblings;
 #endif /* CONFIG_SCHED_MC */
 	u64 last_niffy; /* Last time this RQ updated grq.niffies */
 #endif /* CONFIG_SMP */