+ mm-multi-gen-lru-reuse-some-legacy-trace-events.patch added to mm-unstable branch

+ mm-multi-gen-lru-reuse-some-legacy-trace-events.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: multi-gen LRU: reuse some legacy trace events
has been added to the -mm mm-unstable branch.  Its filename is
     mm-multi-gen-lru-reuse-some-legacy-trace-events.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-multi-gen-lru-reuse-some-legacy-trace-events.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@samsung.com>
Subject: mm: multi-gen LRU: reuse some legacy trace events
Date: Tue, 3 Oct 2023 20:41:55 +0900

As the legacy lru provides, the mglru needs some trace events for
debugging.  Let's reuse following legacy events for the mglru.

  trace_mm_vmscan_lru_isolate
  trace_mm_vmscan_lru_shrink_inactive

Here's an example
  mm_vmscan_lru_isolate: classzone=2 order=0 nr_requested=4096 nr_scanned=64 nr_skipped=0 nr_taken=64 lru=inactive_file
  mm_vmscan_lru_shrink_inactive: nid=0 nr_scanned=64 nr_reclaimed=63 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=1 nr_ref_keep=0 nr_unmap_fail=0 priority=2 flags=RECLAIM_WB_FILE|RECLAIM_WB_ASYNC

Link: https://lkml.kernel.org/r/20231003114155.21869-1-jaewon31.kim@samsung.com
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: T.J. Mercier <tjmercier@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

--- a/mm/vmscan.c~mm-multi-gen-lru-reuse-some-legacy-trace-events
+++ a/mm/vmscan.c
@@ -4328,6 +4328,7 @@ static int scan_folios(struct lruvec *lr
 	int sorted = 0;
 	int scanned = 0;
 	int isolated = 0;
+	int skipped = 0;
 	int remaining = MAX_LRU_BATCH;
 	struct lru_gen_folio *lrugen = &lruvec->lrugen;
 	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
@@ -4341,7 +4342,7 @@ static int scan_folios(struct lruvec *lr
 
 	for (i = MAX_NR_ZONES; i > 0; i--) {
 		LIST_HEAD(moved);
-		int skipped = 0;
+		int skipped_zone = 0;
 		int zone = (sc->reclaim_idx + i) % MAX_NR_ZONES;
 		struct list_head *head = &lrugen->folios[gen][type][zone];
 
@@ -4363,16 +4364,17 @@ static int scan_folios(struct lruvec *lr
 				isolated += delta;
 			} else {
 				list_move(&folio->lru, &moved);
-				skipped += delta;
+				skipped_zone += delta;
 			}
 
-			if (!--remaining || max(isolated, skipped) >= MIN_LRU_BATCH)
+			if (!--remaining || max(isolated, skipped_zone) >= MIN_LRU_BATCH)
 				break;
 		}
 
-		if (skipped) {
+		if (skipped_zone) {
 			list_splice(&moved, head);
-			__count_zid_vm_events(PGSCAN_SKIP, zone, skipped);
+			__count_zid_vm_events(PGSCAN_SKIP, zone, skipped_zone);
+			skipped += skipped_zone;
 		}
 
 		if (!remaining || isolated >= MIN_LRU_BATCH)
@@ -4387,6 +4389,9 @@ static int scan_folios(struct lruvec *lr
 	__count_memcg_events(memcg, item, isolated);
 	__count_memcg_events(memcg, PGREFILL, sorted);
 	__count_vm_events(PGSCAN_ANON + type, isolated);
+	trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, MAX_LRU_BATCH,
+				scanned, skipped, isolated,
+				type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
 
 	/*
 	 * There might not be eligible folios due to reclaim_idx. Check the
@@ -4517,6 +4522,9 @@ static int evict_folios(struct lruvec *l
 retry:
 	reclaimed = shrink_folio_list(&list, pgdat, sc, &stat, false);
 	sc->nr_reclaimed += reclaimed;
+	trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
+			scanned, reclaimed, &stat, sc->priority,
+			type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
 
 	list_for_each_entry_safe_reverse(folio, next, &list, lru) {
 		if (!folio_evictable(folio)) {
_

Patches currently in -mm which might be from jaewon31.kim@samsung.com are

mm-multi-gen-lru-reuse-some-legacy-trace-events.patch