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

This moves vm_swappiness and zone_reclaim_mode to mm/vmscan.c,
as part of the kernel/sysctl.c cleaning, also moves some external
variable declarations and function declarations from include/linux/swap.h
into mm/internal.h.

Signed-off-by: Kaixiong Yu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

Author: yukaixiong

include/linux/swap.h

@@ -433,19 +433,10 @@ extern int vm_swappiness;
 long remove_mapping(struct address_space *mapping, struct folio *folio);
 
 #ifdef CONFIG_NUMA
-extern int node_reclaim_mode;
 extern int sysctl_min_unmapped_ratio;
 extern int sysctl_min_slab_ratio;
-#else
-#define node_reclaim_mode 0
 #endif
 
-static inline bool node_reclaim_enabled(void)
-{
-	/* Is any node_reclaim_mode bit set? */
-	return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP);
-}
-
 void check_move_unevictable_folios(struct folio_batch *fbatch);
 
 extern void __meminit kswapd_run(int nid);

kernel/sysctl.c

@@ -2051,15 +2051,6 @@ static const struct ctl_table vm_table[] = {
 		.proc_handler	= dirtytime_interval_handler,
 		.extra1		= SYSCTL_ZERO,
 	},
-	{
-		.procname	= "swappiness",
-		.data		= &vm_swappiness,
-		.maxlen		= sizeof(vm_swappiness),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_TWO_HUNDRED,
-	},
 	{
 		.procname	= "drop_caches",
 		.data		= &sysctl_drop_caches,
@@ -2107,16 +2098,6 @@ static const struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 #endif
-#ifdef CONFIG_NUMA
-	{
-		.procname	= "zone_reclaim_mode",
-		.data		= &node_reclaim_mode,
-		.maxlen		= sizeof(node_reclaim_mode),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-	},
-#endif
 #ifdef CONFIG_MMU
 	{
 		.procname	= "mmap_min_addr",

mm/internal.h

@@ -1097,9 +1097,13 @@ static inline void mminit_verify_zonelist(void)
 #define NODE_RECLAIM_SUCCESS	1
 
 #ifdef CONFIG_NUMA
+extern int node_reclaim_mode;
+
 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
 #else
+#define node_reclaim_mode 0
+
 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
 				unsigned int order)
 {
@@ -1111,6 +1115,12 @@ static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
 }
 #endif
 
+static inline bool node_reclaim_enabled(void)
+{
+	/* Is any node_reclaim_mode bit set? */
+	return node_reclaim_mode & (RECLAIM_ZONE|RECLAIM_WRITE|RECLAIM_UNMAP);
+}
+
 /*
  * mm/memory-failure.c
  */

mm/vmscan.c

@@ -7404,13 +7404,36 @@ void __meminit kswapd_stop(int nid)
 	pgdat_kswapd_unlock(pgdat);
 }
 
+static const struct ctl_table vmscan_sysctl_table[] = {
+	{
+		.procname	= "swappiness",
+		.data		= &vm_swappiness,
+		.maxlen		= sizeof(vm_swappiness),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_TWO_HUNDRED,
+	},
+#ifdef CONFIG_NUMA
+	{
+		.procname	= "zone_reclaim_mode",
+		.data		= &node_reclaim_mode,
+		.maxlen		= sizeof(node_reclaim_mode),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+	}
+#endif
+};
+
 static int __init kswapd_init(void)
 {
 	int nid;
 
 	swap_setup();
 	for_each_node_state(nid, N_MEMORY)
  		kswapd_run(nid);
+	register_sysctl_init("vm", vmscan_sysctl_table);
 	return 0;
 }