[Devel] [PATCH RHEL10 COMMIT] mm/memcontrol: use lruvec_del_folio() in memcg_numa_isolate_pages()

[Konstantin Khorenko]

The commit is pushed to "branch-rh10-6.12.0-55.13.1.2.x.vz10-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh10-6.12.0-55.13.1.2.3.vz10
------>
commit 44b9e7dae417f29e3fbebb114b3bbee04a373543
Author: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
Date:   Tue Sep 2 18:59:15 2025 +0800

    mm/memcontrol: use lruvec_del_folio() in memcg_numa_isolate_pages()
    
    The lruvec_del_folio() is a universal helper which works fine both with
    old lru and new Multi-Gen LRU, and we want to support the new version.
    So let's switch to lruvec_del_folio().
    
    The lruvec_del_folio() + node_stat_mod_folio() used exactly the same way
    as they are used in isolate_migratepages_block() now already do the same
    as our old __mod_node_page_state/update_lru_sizes, but universaly for
    both cases of lru.
    
    After lruvec_del_folio() let's reinitialize folio->lru (with
    INIT_LIST_HEAD) to allow consecutive list_move().
    
    Let's also remove now unused pgdat and nr_zone_taken variables.
    
    https://virtuozzo.atlassian.net/browse/VSTOR-114298
    Fixes: c92459bc18307 ("mm: memcontrol: add memory.numa_migrate file")
    Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
    
    Feature: mm: interface to migrate memory between NUMA nodes upon userspace request
---
 mm/memcontrol.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6eb8202f5d4c0..4321ac0ef7cb0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3511,8 +3511,6 @@ static long memcg_numa_isolate_pages(struct lruvec *lruvec, enum lru_list lru,
 				     long nr_to_scan, struct list_head *dst)
 {
 	struct list_head *src = &lruvec->lists[lru];
-	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
-	unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
 	long scanned = 0, taken = 0;
 	struct folio *folio = NULL;
 	struct address_space *mapping;
@@ -3626,16 +3624,18 @@ static long memcg_numa_isolate_pages(struct lruvec *lruvec, enum lru_list lru,
 			goto isolate_fail;
 		}
 
+		/* Successfully isolated */
+		lruvec_del_folio(lruvec, folio);
+		INIT_LIST_HEAD(&folio->lru);
+		node_stat_mod_folio(folio, NR_ISOLATED_ANON + folio_is_file_lru(folio),
+				    folio_nr_pages(folio));
+
 		nr_pages = folio_nr_pages(folio);
 		taken += nr_pages;
-		nr_zone_taken[folio_zonenum(folio)] += nr_pages;
 		move_to = dst;
 isolate_fail:
 		list_move(&folio->lru, move_to);
 	}
-	__mod_node_page_state(pgdat, NR_LRU_BASE + lru, -taken);
-	__mod_node_page_state(pgdat, NR_ISOLATED_ANON + is_file_lru(lru), taken);
-	update_lru_sizes(lruvec, lru, nr_zone_taken);
 	spin_unlock_irq(&lruvec->lru_lock);
 
 	return scanned;