[patch 111/262] mm: move fold_vm_numa_events() to fix NUMA without SMP

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Subject: mm: move fold_vm_numa_events() to fix NUMA without SMP

If CONFIG_NUMA=y, but CONFIG_SMP=n (e.g. sh/migor_defconfig):

    sh4-linux-gnu-ld: mm/vmstat.o: in function `vmstat_start':
    vmstat.c:(.text+0x97c): undefined reference to `fold_vm_numa_events'
    sh4-linux-gnu-ld: drivers/base/node.o: in function `node_read_vmstat':
    node.c:(.text+0x140): undefined reference to `fold_vm_numa_events'
    sh4-linux-gnu-ld: drivers/base/node.o: in function `node_read_numastat':
    node.c:(.text+0x1d0): undefined reference to `fold_vm_numa_events'

Fix this by moving fold_vm_numa_events() outside the SMP-only section.

Link: https://lkml.kernel.org/r/9d16ccdd9ef32803d7100c84f737de6a749314fb.1631781495.git.geert+renesas@xxxxxxxxx
Fixes: f19298b9516c1a03 ("mm/vmstat: convert NUMA statistics to basic NUMA counters")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Gon Solo <gonsolo@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/vmstat.c |   56 +++++++++++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 28 deletions(-)

--- a/mm/vmstat.c~mm-move-fold_vm_numa_events-to-fix-numa-without-smp
+++ a/mm/vmstat.c
@@ -165,6 +165,34 @@ atomic_long_t vm_numa_event[NR_VM_NUMA_E
 EXPORT_SYMBOL(vm_zone_stat);
 EXPORT_SYMBOL(vm_node_stat);
 
+#ifdef CONFIG_NUMA
+static void fold_vm_zone_numa_events(struct zone *zone)
+{
+	unsigned long zone_numa_events[NR_VM_NUMA_EVENT_ITEMS] = { 0, };
+	int cpu;
+	enum numa_stat_item item;
+
+	for_each_online_cpu(cpu) {
+		struct per_cpu_zonestat *pzstats;
+
+		pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
+		for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
+			zone_numa_events[item] += xchg(&pzstats->vm_numa_event[item], 0);
+	}
+
+	for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
+		zone_numa_event_add(zone_numa_events[item], zone, item);
+}
+
+void fold_vm_numa_events(void)
+{
+	struct zone *zone;
+
+	for_each_populated_zone(zone)
+		fold_vm_zone_numa_events(zone);
+}
+#endif
+
 #ifdef CONFIG_SMP
 
 int calculate_pressure_threshold(struct zone *zone)
@@ -771,34 +799,6 @@ static int fold_diff(int *zone_diff, int
 	return changes;
 }
 
-#ifdef CONFIG_NUMA
-static void fold_vm_zone_numa_events(struct zone *zone)
-{
-	unsigned long zone_numa_events[NR_VM_NUMA_EVENT_ITEMS] = { 0, };
-	int cpu;
-	enum numa_stat_item item;
-
-	for_each_online_cpu(cpu) {
-		struct per_cpu_zonestat *pzstats;
-
-		pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
-		for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
-			zone_numa_events[item] += xchg(&pzstats->vm_numa_event[item], 0);
-	}
-
-	for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
-		zone_numa_event_add(zone_numa_events[item], zone, item);
-}
-
-void fold_vm_numa_events(void)
-{
-	struct zone *zone;
-
-	for_each_populated_zone(zone)
-		fold_vm_zone_numa_events(zone);
-}
-#endif
-
 /*
  * Update the zone counters for the current cpu.
  *
_