mm: vmstat: move sysctls to mm/vmstat.c

This moves all vmstat related sysctls to its own file, removes useless
extern variable declarations, and do some related clean-ups. To avoid
compiler warnings when CONFIG_PROC_FS is not defined, add the macro
definition CONFIG_PROC_FS ahead CONFIG_NUMA in vmstat.c.

Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>

3 files changed, 40 insertions, 43 deletions

diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 9f3a04345b86..4751e3ecc467 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -10,15 +10,8 @@
 #include <linux/static_key.h>
 #include <linux/mmdebug.h>
 
-extern int sysctl_stat_interval;
-
 #ifdef CONFIG_NUMA
-#define ENABLE_NUMA_STAT   1
-#define DISABLE_NUMA_STAT   0
-extern int sysctl_vm_numa_stat;
 DECLARE_STATIC_KEY_TRUE(vm_numa_stat_key);
-int sysctl_vm_numa_stat_handler(const struct ctl_table *table, int write,
-		void *buffer, size_t *length, loff_t *ppos);
 #endif
 
 struct reclaim_stat {
@@ -304,10 +297,6 @@ void quiet_vmstat(void);
 void cpu_vm_stats_fold(int cpu);
 void refresh_zone_stat_thresholds(void);
 
-struct ctl_table;
-int vmstat_refresh(const struct ctl_table *, int write, void *buffer, size_t *lenp,
-		loff_t *ppos);
-
 void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *);
 
 int calculate_pressure_threshold(struct zone *zone);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index cb57da499ebb..5e6ea570cfea 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -49,7 +49,6 @@
 #include <linux/limits.h>
 #include <linux/dcache.h>
 #include <linux/syscalls.h>
-#include <linux/vmstat.h>
 #include <linux/nfs_fs.h>
 #include <linux/acpi.h>
 #include <linux/reboot.h>
@@ -2071,17 +2070,6 @@ static const struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_TWO_HUNDRED,
 	},
-#ifdef CONFIG_NUMA
-	{
-		.procname	= "numa_stat",
-		.data		= &sysctl_vm_numa_stat,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= sysctl_vm_numa_stat_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-#endif
 	{
 		.procname	= "drop_caches",
 		.data		= &sysctl_drop_caches,
@@ -2147,22 +2135,6 @@ static const struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 #endif
-#ifdef CONFIG_SMP
-	{
-		.procname	= "stat_interval",
-		.data		= &sysctl_stat_interval,
-		.maxlen		= sizeof(sysctl_stat_interval),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_jiffies,
-	},
-	{
-		.procname	= "stat_refresh",
-		.data		= NULL,
-		.maxlen		= 0,
-		.mode		= 0600,
-		.proc_handler	= vmstat_refresh,
-	},
-#endif
 #ifdef CONFIG_MMU
 	{
 		.procname	= "mmap_min_addr",
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 16bfe1c694dd..39704b5b17e0 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -31,8 +31,10 @@
 
 #include "internal.h"
 
+#ifdef CONFIG_PROC_FS
 #ifdef CONFIG_NUMA
-int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
+#define ENABLE_NUMA_STAT 1
+static int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
 
 /* zero numa counters within a zone */
 static void zero_zone_numa_counters(struct zone *zone)
@@ -74,7 +76,7 @@ static void invalid_numa_statistics(void)
 
 static DEFINE_MUTEX(vm_numa_stat_lock);
 
-int sysctl_vm_numa_stat_handler(const struct ctl_table *table, int write,
+static int sysctl_vm_numa_stat_handler(const struct ctl_table *table, int write,
 		void *buffer, size_t *length, loff_t *ppos)
 {
 	int ret, oldval;
@@ -102,6 +104,7 @@ out:
 	return ret;
 }
 #endif
+#endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
@@ -1938,7 +1941,7 @@ static const struct seq_operations vmstat_op = {
 
 #ifdef CONFIG_SMP
 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
-int sysctl_stat_interval __read_mostly = HZ;
+static int sysctl_stat_interval __read_mostly = HZ;
 static int vmstat_late_init_done;
 
 #ifdef CONFIG_PROC_FS
@@ -1947,7 +1950,7 @@ static void refresh_vm_stats(struct work_struct *work)
 	refresh_cpu_vm_stats(true);
 }
 
-int vmstat_refresh(const struct ctl_table *table, int write,
+static int vmstat_refresh(const struct ctl_table *table, int write,
 		   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	long val;
@@ -2196,6 +2199,38 @@ static int __init vmstat_late_init(void)
 late_initcall(vmstat_late_init);
 #endif
 
+#ifdef CONFIG_PROC_FS
+static const struct ctl_table vmstat_table[] = {
+#ifdef CONFIG_SMP
+	{
+		.procname	= "stat_interval",
+		.data		= &sysctl_stat_interval,
+		.maxlen		= sizeof(sysctl_stat_interval),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
+		.procname	= "stat_refresh",
+		.data		= NULL,
+		.maxlen		= 0,
+		.mode		= 0600,
+		.proc_handler	= vmstat_refresh,
+	},
+#endif
+#ifdef CONFIG_NUMA
+	{
+		.procname	= "numa_stat",
+		.data		= &sysctl_vm_numa_stat,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= sysctl_vm_numa_stat_handler,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+#endif
+};
+#endif
+
 struct workqueue_struct *mm_percpu_wq;
 
 void __init init_mm_internals(void)
@@ -2227,6 +2262,7 @@ void __init init_mm_internals(void)
 	proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
 	proc_create_seq("vmstat", 0444, NULL, &vmstat_op);
 	proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
+	register_sysctl_init("vm", vmstat_table);
 #endif
 }