On Wed, 13 Mar 2024, Sasha Levin wrote:
From: Kefeng Wang wangkefeng.wang@huawei.com
[ 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,
- for a tail/base page, order = 0, for a head page, the order > 0 && PageTransHuge() is true
- 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
- even though the page is a tail page, isolate_lru_page() will post a warning, and fail to isolate the page
- 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@huawei.co... Link: https://lkml.kernel.org/r/20230913095131.2426871-2-wangkefeng.wang@huawei.co... Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com Suggested-by: Matthew Wilcox (Oracle) willy@infradead.org Cc: David Hildenbrand david@redhat.com Cc: Huang Ying ying.huang@intel.com Cc: Hugh Dickins hughd@google.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Zi Yan ziy@nvidia.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 2774f256e7c0 ("mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index")
No it is not: that one is appropriate to include, this one is not.
Hugh
Signed-off-by: Sasha Levin sashal@kernel.org
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