The patch titled
Subject: mm: migrate: remove THP mapcount check in numamigrate_isolate_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-migrate-remove-thp-mapcount-check-in-numamigrate_isolate_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate-remove-thp-mapcount-check-in-numamigrate_isolate_page.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: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: migrate: remove THP mapcount check in numamigrate_isolate_page()
Date: Wed, 13 Sep 2023 17:51:25 +0800
The check of THP mapped by multiple processes was introduced by commit
04fa5d6a6547 ("mm: migrate: check page_count of THP before migrating") and
refactor by commit 340ef3902cf2 ("mm: numa: cleanup flow of transhuge page
migration"), which is out of date, since migrate_misplaced_page() is now
using the standard migrate_pages() for small pages and THPs, the reference
count checking is in folio_migrate_mapping(), so let's remove the special
check for THP.
Link: https://lkml.kernel.org/r/20230913095131.2426871-3-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 4 ----
1 file changed, 4 deletions(-)
--- a/mm/migrate.c~mm-migrate-remove-thp-mapcount-check-in-numamigrate_isolate_page
+++ a/mm/migrate.c
@@ -2483,10 +2483,6 @@ static int numamigrate_isolate_page(pg_d
int nr_pages = thp_nr_pages(page);
int order = compound_order(page);
- /* Do not migrate THP mapped by multiple processes */
- if (PageTransHuge(page) && total_mapcount(page) > 1)
- return 0;
-
/* Avoid migrating to a node that is nearly full */
if (!migrate_balanced_pgdat(pgdat, nr_pages)) {
int z;
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-migrate-remove-pagetranshuge-check-in-numamigrate_isolate_page.patch
mm-migrate-remove-thp-mapcount-check-in-numamigrate_isolate_page.patch
mm-migrate-convert-numamigrate_isolate_page-to-numamigrate_isolate_folio.patch
mm-migrate-convert-migrate_misplaced_page-to-migrate_misplaced_folio.patch
mm-migrate-use-__folio_test_movable.patch
mm-migrate-use-a-folio-in-add_page_for_migration.patch
mm-migrate-remove-pagehead-check-for-hugetlb-in-add_page_for_migration.patch
mm-migrate-remove-isolated-variable-in-add_page_for_migration.patch
