1 files changed, 71 insertions, 0 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 7d11554..40b2db6 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -32,6 +32,77 @@
 
 #define NUMA_STATS_THRESHOLD (U16_MAX - 2)
 
+#ifdef CONFIG_NUMA
+int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
+
+/* zero numa counters within a zone */
+static void zero_zone_numa_counters(struct zone *zone)
+{
+	int item, cpu;
+
+	for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) {
+		atomic_long_set(&zone->vm_numa_stat[item], 0);
+		for_each_online_cpu(cpu)
+			per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item]
+						= 0;
+	}
+}
+
+/* zero numa counters of all the populated zones */
+static void zero_zones_numa_counters(void)
+{
+	struct zone *zone;
+
+	for_each_populated_zone(zone)
+		zero_zone_numa_counters(zone);
+}
+
+/* zero global numa counters */
+static void zero_global_numa_counters(void)
+{
+	int item;
+
+	for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++)
+		atomic_long_set(&vm_numa_stat[item], 0);
+}
+
+static void invalid_numa_statistics(void)
+{
+	zero_zones_numa_counters();
+	zero_global_numa_counters();
+}
+
+static DEFINE_MUTEX(vm_numa_stat_lock);
+
+int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
+		void __user *buffer, size_t *length, loff_t *ppos)
+{
+	int ret, oldval;
+
+	mutex_lock(&vm_numa_stat_lock);
+	if (write)
+		oldval = sysctl_vm_numa_stat;
+	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
+	if (ret || !write)
+		goto out;
+
+	if (oldval == sysctl_vm_numa_stat)
+		goto out;
+	else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) {
+		static_branch_enable(&vm_numa_stat_key);
+		pr_info("enable numa statistics\n");
+	} else {
+		static_branch_disable(&vm_numa_stat_key);
+		invalid_numa_statistics();
+		pr_info("disable numa statistics, and clear numa counters\n");
+	}
+
+out:
+	mutex_unlock(&vm_numa_stat_lock);
+	return ret;
+}
+#endif
+
 #ifdef CONFIG_VM_EVENT_COUNTERS
 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
 EXPORT_PER_CPU_SYMBOL(vm_event_states);