From 5fe690a5946442f7f2d08448341dd621367f80bc Mon Sep 17 00:00:00 2001
From: Matthew Cassell <mcassell411@gmail.com>
Date: Mon, 22 Jul 2024 17:13:16 +0000
Subject: [PATCH] mm: add node_reclaim successes to VM event counters
/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.
Link: https://lkml.kernel.org/r/20240722171316.7517-1-mcassell411@gmail.com
Signed-off-by: Matthew Cassell <mcassell411@gmail.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
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 747943bc8cc2d..6fff8ed3b1fd0 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 cfa839284b923..c9682c8a1d754 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -7539,7 +7539,9 @@ 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 e875f2a4915f5..1ac2a569b6cf6 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1314,6 +1314,7 @@ const char * const vmstat_text[] = {
"pgsteal_file",
#ifdef CONFIG_NUMA
+ "zone_reclaim_success",
"zone_reclaim_failed",
#endif
"pginodesteal",