The patch titled
Subject: mm: migrate: remove PageTransHuge check in numamigrate_isolate_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-migrate-remove-pagetranshuge-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-pagetranshuge-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
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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: migrate: remove PageTransHuge check in numamigrate_isolate_page()
Date: Wed, 13 Sep 2023 17:51:24 +0800
Patch series "mm: migrate: more folio conversion and unification", v3.
Convert more migrate functions to use a folio, it is also a preparation
for large folio migration support when balancing numa.
This patch (of 8):
The assert VM_BUG_ON_PAGE(order && !PageTransHuge(page), page) is not very
useful,
1) for a tail/base page, order = 0, for a head page, the order > 0 &&
PageTransHuge() is true
2) there is a PageCompound() check and only base page is handled in
do_numa_page(), and do_huge_pmd_numa_page() only handle PMD-mapped
THP
3) even though the page is a tail page, isolate_lru_page() will post
a warning, and fail to isolate the page
4) if large folio/pte-mapped THP migration supported in the future,
we could migrate the entire folio if numa fault on a tail page
so just remove the check.
Link: https://lkml.kernel.org/r/20230913095131.2426871-1-wangkefeng.wang@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230913095131.2426871-2-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
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 | 2 --
1 file changed, 2 deletions(-)
--- a/mm/migrate.c~mm-migrate-remove-pagetranshuge-check-in-numamigrate_isolate_page
+++ a/mm/migrate.c
@@ -2483,8 +2483,6 @@ static int numamigrate_isolate_page(pg_d
int nr_pages = thp_nr_pages(page);
int order = compound_order(page);
- VM_BUG_ON_PAGE(order && !PageTransHuge(page), page);
-
/* Do not migrate THP mapped by multiple processes */
if (PageTransHuge(page) && total_mapcount(page) > 1)
return 0;
_
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
