From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
[ Upstream commit a8ac4a767dcd9d87d8229045904d9fe15ea5e0e8 ]
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>
Stable-dep-of: 2774f256e7c0 ("mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
mm/migrate.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index b4d972d80b10c..6f8ad6b64c9bc 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2506,8 +2506,6 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
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;
--
2.43.0
