The patch titled
Subject: mm/migration: fix potential page refcounts leak in migrate_pages
has been added to the -mm tree. Its filename is
mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/migration: fix potential page refcounts leak in migrate_pages
In -ENOMEM case, there might be some subpages of fail-to-migrate THPs left
in thp_split_pages list. We should move them back to migration list so
that they could be put back to the right list by the caller otherwise the
page refcnt will be leaked here. Also adjust nr_failed and nr_thp_failed
accordingly to make vm events account more accurate.
Link: https://lkml.kernel.org/r/20220318111709.60311-10-linmiaohe@xxxxxxxxxx
Fixes: b5bade978e9b ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/mm/migrate.c~mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages
+++ a/mm/migrate.c
@@ -1434,6 +1434,14 @@ retry:
}
nr_failed_pages += nr_subpages;
+ /*
+ * There might be some subpages of fail-to-migrate THPs
+ * left in thp_split_pages list. Move them back to migration
+ * list so that they could be put back to the right list by
+ * the caller otherwise the page refcnt will be leaked.
+ */
+ list_splice_init(&thp_split_pages, from);
+ nr_thp_failed += thp_retry;
goto out;
case -EAGAIN:
if (is_thp)
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-shmem-make-shmem_init-return-void.patch
mm-memcg-remove-unneeded-nr_scanned.patch
mm-mremap-use-helper-mlock_future_check.patch
mm-mlock-fix-two-bugs-in-user_shm_lock.patch
mm-compaction-use-helper-isolation_suitable.patch
mm-migration-remove-unneeded-local-variable-mapping_locked.patch
mm-migration-remove-unneeded-out-label.patch
mm-migration-remove-unneeded-local-variable-page_lru.patch
mm-migration-fix-the-confusing-pagetranshuge-check.patch
mm-migration-use-helper-function-vma_lookup-in-add_page_for_migration.patch
mm-migration-use-helper-macro-min-in-do_pages_stat.patch
mm-migration-avoid-unneeded-nodemask_t-initialization.patch
mm-migration-remove-some-duplicated-codes-in-migrate_pages.patch
mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch
mm-migration-fix-possible-do_pages_stat_array-racing-with-memory-offline.patch
