pgdemote_src_*: pages demoted from this node.
pgdemote_dst_*: pages demoted to this node.
So that we are able to know their demotion per-node stats by checking this.
In the environment, node0 and node1 are DRAM, node3 is PMEM.
Global stats:
$ grep -E 'demote' /proc/vmstat
pgdemote_src_kswapd 130155
pgdemote_src_direct 113497
pgdemote_src_khugepaged 0
pgdemote_dst_kswapd 130155
pgdemote_dst_direct 113497
pgdemote_dst_khugepaged 0
Per-node stats:
$ grep demote /sys/devices/system/node/node0/vmstat
pgdemote_src_kswapd 68454
pgdemote_src_direct 83431
pgdemote_src_khugepaged 0
pgdemote_dst_kswapd 0
pgdemote_dst_direct 0
pgdemote_dst_khugepaged 0
$ grep demote /sys/devices/system/node/node1/vmstat
pgdemote_src_kswapd 185834
pgdemote_src_direct 30066
pgdemote_src_khugepaged 0
pgdemote_dst_kswapd 0
pgdemote_dst_direct 0
pgdemote_dst_khugepaged 0
$ grep demote /sys/devices/system/node/node3/vmstat
pgdemote_src_kswapd 0
pgdemote_src_direct 0
pgdemote_src_khugepaged 0
pgdemote_dst_kswapd 254288
pgdemote_dst_direct 113497
pgdemote_dst_khugepaged 0
>From above stats, we know node3 is the demotion destination which one
the node0 and node1 will demote to.
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
RFC: their names are open to discussion, maybe pgdemote_from/to_*
Another defect of this patch is that, SUM(pgdemote_src_*) is always same
as SUM(pgdemote_dst_*) in the global stats, shall we hide one of them.
---
include/linux/mmzone.h | 9 ++++++---
mm/vmscan.c | 13 ++++++++++---
mm/vmstat.c | 9 ++++++---
3 files changed, 22 insertions(+), 9 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ad0309eea850..a6140d894bec 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -207,9 +207,12 @@ enum node_stat_item {
PGPROMOTE_SUCCESS, /* promote successfully */
PGPROMOTE_CANDIDATE, /* candidate pages to promote */
/* PGDEMOTE_*: pages demoted */
- PGDEMOTE_KSWAPD,
- PGDEMOTE_DIRECT,
- PGDEMOTE_KHUGEPAGED,
+ PGDEMOTE_SRC_KSWAPD,
+ PGDEMOTE_SRC_DIRECT,
+ PGDEMOTE_SRC_KHUGEPAGED,
+ PGDEMOTE_DST_KSWAPD,
+ PGDEMOTE_DST_DIRECT,
+ PGDEMOTE_DST_KHUGEPAGED,
#endif
NR_VM_NODE_STAT_ITEMS
};
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2f1fb4ec3235..55d2287d7150 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1111,13 +1111,18 @@ void drop_slab(void)
static int reclaimer_offset(void)
{
BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD !=
- PGDEMOTE_DIRECT - PGDEMOTE_KSWAPD);
+ PGDEMOTE_SRC_DIRECT - PGDEMOTE_SRC_KSWAPD);
BUILD_BUG_ON(PGSTEAL_DIRECT - PGSTEAL_KSWAPD !=
PGSCAN_DIRECT - PGSCAN_KSWAPD);
BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD !=
- PGDEMOTE_KHUGEPAGED - PGDEMOTE_KSWAPD);
+ PGDEMOTE_SRC_KHUGEPAGED - PGDEMOTE_SRC_KSWAPD);
BUILD_BUG_ON(PGSTEAL_KHUGEPAGED - PGSTEAL_KSWAPD !=
PGSCAN_KHUGEPAGED - PGSCAN_KSWAPD);
+ BUILD_BUG_ON(PGDEMOTE_SRC_DIRECT - PGDEMOTE_SRC_KSWAPD !=
+ PGDEMOTE_DST_DIRECT - PGDEMOTE_DST_KSWAPD);
+ BUILD_BUG_ON(PGDEMOTE_SRC_KHUGEPAGED - PGDEMOTE_SRC_KSWAPD !=
+ PGDEMOTE_DST_KHUGEPAGED - PGDEMOTE_DST_KSWAPD);
+
if (current_is_kswapd())
return 0;
@@ -1678,8 +1683,10 @@ static unsigned int demote_folio_list(struct list_head *demote_folios,
(unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION,
&nr_succeeded);
+ mod_node_page_state(pgdat,
+ PGDEMOTE_SRC_KSWAPD + reclaimer_offset(), nr_succeeded);
mod_node_page_state(NODE_DATA(target_nid),
- PGDEMOTE_KSWAPD + reclaimer_offset(), nr_succeeded);
+ PGDEMOTE_DST_KSWAPD + reclaimer_offset(), nr_succeeded);
return nr_succeeded;
}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index f141c48c39e4..63f106a5e008 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1244,9 +1244,12 @@ const char * const vmstat_text[] = {
#ifdef CONFIG_NUMA_BALANCING
"pgpromote_success",
"pgpromote_candidate",
- "pgdemote_kswapd",
- "pgdemote_direct",
- "pgdemote_khugepaged",
+ "pgdemote_src_kswapd",
+ "pgdemote_src_direct",
+ "pgdemote_src_khugepaged",
+ "pgdemote_dst_kswapd",
+ "pgdemote_dst_direct",
+ "pgdemote_dst_khugepaged",
#endif
/* enum writeback_stat_item counters */
--
2.29.2
