/proc/vmstat currently shows the number of node_reclaim() failures when
vm.zone_reclaim_mode is set appropriately. It would be convenient to have
the number of successes right next to zone_reclaim_failed (similar to
compaction and migration).
While just a trivially addition to the vmstat file. It was helpful during
benchmarking to not have to probe node_reclaim() to observe the
success/failure ratio.
Signed-off-by: Matthew Cassell <mcassell411@xxxxxxxxx>
---
include/linux/vm_event_item.h | 1 +
mm/vmscan.c | 4 +++-
mm/vmstat.c | 1 +
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 747943bc8cc2..6fff8ed3b1fd 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -50,6 +50,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
PGSTEAL_ANON,
PGSTEAL_FILE,
#ifdef CONFIG_NUMA
+ PGSCAN_ZONE_RECLAIM_SUCCESS,
PGSCAN_ZONE_RECLAIM_FAILED,
#endif
PGINODESTEAL, SLABS_SCANNED, KSWAPD_INODESTEAL,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2e34de9cd0d4..321f259d713a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -7496,7 +7496,9 @@ int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
ret = __node_reclaim(pgdat, gfp_mask, order);
clear_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags);
- if (!ret)
+ if (ret)
+ count_vm_event(PGSCAN_ZONE_RECLAIM_SUCCESS);
+ else
count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);
return ret;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 8507c497218b..27e02b188da8 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1295,6 +1295,7 @@ const char * const vmstat_text[] = {
"pgsteal_file",
#ifdef CONFIG_NUMA
+ "zone_reclaim_success",
"zone_reclaim_failed",
#endif
"pginodesteal",
--
2.34.1
