[patch v12 11/13] mm: vmstat: move need_update

Marcelo Tosatti
2022-03-15T19:56:01Z

Move need_update() function up in vmstat.c, needed by next patch.
No code changes.

Remove a duplicate comment while at it.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---
mm/vmstat.c | 58 +++++++++++++++++++++++++++++-----------------------------
1 file changed, 29 insertions(+), 29 deletions(-)

Index: linux-2.6/mm/vmstat.c
===================================================================
--- linux-2.6.orig/mm/vmstat.c
+++ linux-2.6/mm/vmstat.c
@@ -1894,6 +1894,35 @@ static const struct seq_operations vmsta
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
int sysctl_stat_interval __read_mostly = HZ;

+/*
+ * Check if the diffs for a certain cpu indicate that
+ * an update is needed.
+ */
+static bool need_update(int cpu)
+{
+ pg_data_t *last_pgdat = NULL;
+ struct zone *zone;
+
+ for_each_populated_zone(zone) {
+ struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
+ struct per_cpu_nodestat *n;
+
+ /*
+ * The fast way of checking if there are any vmstat diffs.
+ */
+ if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff)))
+ return true;
+
+ if (last_pgdat == zone->zone_pgdat)
+ continue;
+ last_pgdat = zone->zone_pgdat;
+ n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
+ if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff)))
+ return true;
+ }
+ return false;
+}
+
#ifdef CONFIG_PROC_FS
static void refresh_vm_stats(struct work_struct *work)
{
@@ -1975,35 +2004,6 @@ static void vmstat_update(struct work_st
}

/*
- * Check if the diffs for a certain cpu indicate that
- * an update is needed.
- */
-static bool need_update(int cpu)
-{
- pg_data_t *last_pgdat = NULL;
- struct zone *zone;
-
- for_each_populated_zone(zone) {
- struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
- struct per_cpu_nodestat *n;
-
- /*
- * The fast way of checking if there are any vmstat diffs.
- */
- if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff)))
- return true;
-
- if (last_pgdat == zone->zone_pgdat)
- continue;
- last_pgdat = zone->zone_pgdat;
- n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
- if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff)))
- return true;
- }
- return false;
-}
-
-/*
* Switch off vmstat processing and then fold all the remaining differentials
* until the diffs stay at zero. The function is used by NOHZ and can only be
* invoked when tick processing is not active.