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

Yury Norov
2023-04-20T05:20:51Z

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