mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING

Demotion can work well without CONFIG_NUMA_BALANCING.  But the commit
23e9f01 ("mm/vmstat: move pgdemote_* to per-node stats") wrongly hid
it behind CONFIG_NUMA_BALANCING.

Fix it by moving them out of CONFIG_NUMA_BALANCING.

Link: https://lkml.kernel.org/r/20231229022651.3229174-1-lizhijian@fujitsu.com
Fixes: 23e9f01 ("mm/vmstat: move pgdemote_* to per-node stats")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: zhijianli88

include/linux/mmzone.h

@@ -207,11 +207,11 @@ enum node_stat_item {
 #ifdef CONFIG_NUMA_BALANCING
 	PGPROMOTE_SUCCESS,	/* promote successfully */
 	PGPROMOTE_CANDIDATE,	/* candidate pages to promote */
+#endif
 	/* PGDEMOTE_*: pages demoted */
 	PGDEMOTE_KSWAPD,
 	PGDEMOTE_DIRECT,
 	PGDEMOTE_KHUGEPAGED,
-#endif
 	NR_VM_NODE_STAT_ITEMS
 };
 

mm/vmscan.c

@@ -409,12 +409,10 @@ void drop_slab(void)
 
 static int reclaimer_offset(void)
 {
-#ifdef CONFIG_NUMA_BALANCING
 	BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD !=
 			PGDEMOTE_DIRECT - PGDEMOTE_KSWAPD);
 	BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD !=
 			PGDEMOTE_KHUGEPAGED - PGDEMOTE_KSWAPD);
-#endif
 	BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD !=
 			PGSCAN_DIRECT - PGSCAN_KSWAPD);
 	BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD !=
@@ -978,10 +976,9 @@ static unsigned int demote_folio_list(struct list_head *demote_folios,
 	migrate_pages(demote_folios, alloc_demote_folio, NULL,
 		      (unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION,
 		      &nr_succeeded);
-#ifdef CONFIG_NUMA_BALANCING
+
 	mod_node_page_state(pgdat, PGDEMOTE_KSWAPD + reclaimer_offset(),
 			    nr_succeeded);
-#endif
 
 	return nr_succeeded;
 }

mm/vmstat.c

@@ -1248,10 +1248,10 @@ const char * const vmstat_text[] = {
 #ifdef CONFIG_NUMA_BALANCING
 	"pgpromote_success",
 	"pgpromote_candidate",
+#endif
 	"pgdemote_kswapd",
 	"pgdemote_direct",
 	"pgdemote_khugepaged",
-#endif
 
 	/* enum writeback_stat_item counters */
 	"nr_dirty_threshold",