[RFC PATCH v3 3/8] mm: migrate: allocate the right size of non hugetlb or THP compound pages.
From: Zi Yan <hidden>
Date: 2022-01-05 21:48:49
Also in:
linux-iommu, linux-mm, lkml
Subsystem:
memory management, memory management - memory policy and migration, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Zi Yan <ziy@nvidia.com> alloc_migration_target() is used by alloc_contig_range() and non-LRU movable compound pages can be migrated. Current code does not allocate the right page size for such pages. Check THP precisely using is_transparent_huge() and add allocation support for non-LRU compound pages. Signed-off-by: Zi Yan <ziy@nvidia.com> --- mm/migrate.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index c7da064b4781..b1851ffb8576 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c@@ -1546,9 +1546,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private) gfp_mask = htlb_modify_alloc_mask(h, gfp_mask); return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask); - } - - if (PageTransHuge(page)) { + } else if (is_transparent_hugepage(page)) { /* * clear __GFP_RECLAIM to make the migration callback * consistent with regular THP allocations.
@@ -1556,14 +1554,19 @@ struct page *alloc_migration_target(struct page *page, unsigned long private) gfp_mask &= ~__GFP_RECLAIM; gfp_mask |= GFP_TRANSHUGE; order = HPAGE_PMD_ORDER; + } else if (PageCompound(page)) { + /* for non-LRU movable compound pages */ + gfp_mask |= __GFP_COMP; + order = compound_order(page); } + zidx = zone_idx(page_zone(page)); if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE) gfp_mask |= __GFP_HIGHMEM; new_page = __alloc_pages(gfp_mask, order, nid, mtc->nmask); - if (new_page && PageTransHuge(new_page)) + if (new_page && is_transparent_hugepage(page)) prep_transhuge_page(new_page); return new_page;
--
2.34.1