[PATCH v2 6/8] sched/topology: export sched_domains_numa_levels

[Yury Norov <yury.norov@gmail.com>]

The following patch adds a test for NUMA-aware CPU enumerators, and it
requires an access to sched_domains_numa_levels.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 include/linux/topology.h |  7 +++++++
 kernel/sched/topology.c  | 10 ++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/include/linux/topology.h b/include/linux/topology.h
index 01fb3a55d7ce..7ebcc886dc76 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -43,6 +43,13 @@
 	for_each_online_node(node)			\
 		if (nr_cpus_node(node))
 
+#ifdef CONFIG_NUMA
+extern int __sched_domains_numa_levels;
+#define sched_domains_numa_levels ((const int)__sched_domains_numa_levels)
+#else
+#define sched_domains_numa_levels (1)
+#endif
+
 int arch_update_cpu_topology(void);
 
 /* Conform to ACPI 2.0 SLIT distance definitions */
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index fc163e4181e6..56daa279c411 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1508,7 +1508,9 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
 #ifdef CONFIG_NUMA
 enum numa_topology_type sched_numa_topology_type;
 
-static int			sched_domains_numa_levels;
+int				__sched_domains_numa_levels;
+EXPORT_SYMBOL_GPL(__sched_domains_numa_levels);
+
 static int			sched_domains_curr_level;
 
 int				sched_max_numa_distance;
@@ -1872,7 +1874,7 @@ void sched_init_numa(int offline_node)
 	 *
 	 * We reset it to 'nr_levels' at the end of this function.
 	 */
-	sched_domains_numa_levels = 0;
+	__sched_domains_numa_levels = 0;
 
 	masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL);
 	if (!masks)
@@ -1948,7 +1950,7 @@ void sched_init_numa(int offline_node)
 	sched_domain_topology_saved = sched_domain_topology;
 	sched_domain_topology = tl;
 
-	sched_domains_numa_levels = nr_levels;
+	__sched_domains_numa_levels = nr_levels;
 	WRITE_ONCE(sched_max_numa_distance, sched_domains_numa_distance[nr_levels - 1]);
 
 	init_numa_topology_type(offline_node);
@@ -1961,7 +1963,7 @@ static void sched_reset_numa(void)
 	struct cpumask ***masks;
 
 	nr_levels = sched_domains_numa_levels;
-	sched_domains_numa_levels = 0;
+	__sched_domains_numa_levels = 0;
 	sched_max_numa_distance = 0;
 	sched_numa_topology_type = NUMA_DIRECT;
 	distances = sched_domains_numa_distance;
-- 
2.34.1