The patch titled
Subject: vmscan: add a vmscan event for reclaim_pages
has been added to the -mm mm-unstable branch. Its filename is
vmscan-add-a-vmscan-event-for-reclaim_pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vmscan-add-a-vmscan-event-for-reclaim_pages.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
Subject: vmscan: add a vmscan event for reclaim_pages
Date: Fri, 11 Oct 2024 21:49:28 +0900
reclaim_folio_list() uses a dummy reclaim_stat and is not being used. To
know the memory stat, add a new trace event. This is useful how how many
pages are not reclaimed or why.
This is an example.
mm_vmscan_reclaim_pages: nid=0 nr_scanned=112 nr_reclaimed=112 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0
Currenlty reclaim_folio_list is only called by reclaim_pages, and
reclaim_pages is used by damon and madvise. In the latest Android,
reclaim_pages is also used by shmem to reclaim all pages in a
address_space.
Link: https://lkml.kernel.org/r/20241011124928.1224813-1-jaewon31.kim@xxxxxxxxxxx
Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
Cc: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
Cc: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/vmscan.h | 45 ++++++++++++++++++++++++++++++++
mm/vmscan.c | 16 +++++++----
2 files changed, 56 insertions(+), 5 deletions(-)
--- a/include/trace/events/vmscan.h~vmscan-add-a-vmscan-event-for-reclaim_pages
+++ a/include/trace/events/vmscan.h
@@ -346,6 +346,51 @@ TRACE_EVENT(mm_vmscan_write_folio,
show_reclaim_flags(__entry->reclaim_flags))
);
+TRACE_EVENT(mm_vmscan_reclaim_pages,
+
+ TP_PROTO(int nid,
+ unsigned long nr_scanned, unsigned long nr_reclaimed,
+ struct reclaim_stat *stat),
+
+ TP_ARGS(nid, nr_scanned, nr_reclaimed, stat),
+
+ TP_STRUCT__entry(
+ __field(int, nid)
+ __field(unsigned long, nr_scanned)
+ __field(unsigned long, nr_reclaimed)
+ __field(unsigned long, nr_dirty)
+ __field(unsigned long, nr_writeback)
+ __field(unsigned long, nr_congested)
+ __field(unsigned long, nr_immediate)
+ __field(unsigned int, nr_activate0)
+ __field(unsigned int, nr_activate1)
+ __field(unsigned long, nr_ref_keep)
+ __field(unsigned long, nr_unmap_fail)
+ ),
+
+ TP_fast_assign(
+ __entry->nid = nid;
+ __entry->nr_scanned = nr_scanned;
+ __entry->nr_reclaimed = nr_reclaimed;
+ __entry->nr_dirty = stat->nr_dirty;
+ __entry->nr_writeback = stat->nr_writeback;
+ __entry->nr_congested = stat->nr_congested;
+ __entry->nr_immediate = stat->nr_immediate;
+ __entry->nr_activate0 = stat->nr_activate[0];
+ __entry->nr_activate1 = stat->nr_activate[1];
+ __entry->nr_ref_keep = stat->nr_ref_keep;
+ __entry->nr_unmap_fail = stat->nr_unmap_fail;
+ ),
+
+ TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld",
+ __entry->nid,
+ __entry->nr_scanned, __entry->nr_reclaimed,
+ __entry->nr_dirty, __entry->nr_writeback,
+ __entry->nr_congested, __entry->nr_immediate,
+ __entry->nr_activate0, __entry->nr_activate1,
+ __entry->nr_ref_keep, __entry->nr_unmap_fail)
+);
+
TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
TP_PROTO(int nid,
--- a/mm/vmscan.c~vmscan-add-a-vmscan-event-for-reclaim_pages
+++ a/mm/vmscan.c
@@ -2126,9 +2126,10 @@ static void shrink_active_list(unsigned
}
static unsigned int reclaim_folio_list(struct list_head *folio_list,
+ unsigned int nr_scanned,
struct pglist_data *pgdat)
{
- struct reclaim_stat dummy_stat;
+ struct reclaim_stat stat;
unsigned int nr_reclaimed;
struct folio *folio;
struct scan_control sc = {
@@ -2139,12 +2140,13 @@ static unsigned int reclaim_folio_list(s
.no_demotion = 1,
};
- nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true);
+ nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &stat, true);
while (!list_empty(folio_list)) {
folio = lru_to_folio(folio_list);
list_del(&folio->lru);
folio_putback_lru(folio);
}
+ trace_mm_vmscan_reclaim_pages(pgdat->node_id, nr_scanned, nr_reclaimed, &stat);
return nr_reclaimed;
}
@@ -2152,6 +2154,7 @@ static unsigned int reclaim_folio_list(s
unsigned long reclaim_pages(struct list_head *folio_list)
{
int nid;
+ unsigned int nr_scanned = 0;
unsigned int nr_reclaimed = 0;
LIST_HEAD(node_folio_list);
unsigned int noreclaim_flag;
@@ -2168,15 +2171,18 @@ unsigned long reclaim_pages(struct list_
if (nid == folio_nid(folio)) {
folio_clear_active(folio);
list_move(&folio->lru, &node_folio_list);
+ nr_scanned += folio_nr_pages(folio);
continue;
}
- nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid));
+ nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned,
+ NODE_DATA(nid));
+ nr_scanned = 0;
nid = folio_nid(lru_to_folio(folio_list));
} while (!list_empty(folio_list));
- nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid));
-
+ nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned,
+ NODE_DATA(nid));
memalloc_noreclaim_restore(noreclaim_flag);
return nr_reclaimed;
_
Patches currently in -mm which might be from jaewon31.kim@xxxxxxxxxxx are
vmscan-add-a-vmscan-event-for-reclaim_pages.patch
