[RFC PATCH 06/15] mm: use PAGES_PER_SECTION instead for mem_map_offset/next().
From: Zi Yan <hidden>
Date: 2021-08-05 19:04:03
Also in:
lkml
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Zi Yan <ziy@nvidia.com> mem_map is only guaranteed to be virtually contiguous within a section, so mem_map_offset/next() uses pfn to handle mem_map discontiguity. Use PAGES_PER_SECTION instead of MAX_ORDER_NR_PAGES to describe this condition more precisely. Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/internal.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index b1001ebeb286..4ca52c696902 100644
--- a/mm/internal.h
+++ b/mm/internal.h@@ -485,7 +485,7 @@ static inline void vunmap_range_noflush(unsigned long start, unsigned long end) */ static inline struct page *mem_map_offset(struct page *base, int offset) { - if (unlikely(offset >= MAX_ORDER_NR_PAGES)) + if (unlikely(offset >= PAGES_PER_SECTION)) return nth_page(base, offset); return base + offset; }
@@ -497,7 +497,7 @@ static inline struct page *mem_map_offset(struct page *base, int offset) static inline struct page *mem_map_next(struct page *iter, struct page *base, int offset) { - if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { + if (unlikely((offset & (PAGES_PER_SECTION - 1)) == 0)) { unsigned long pfn = page_to_pfn(base) + offset; if (!pfn_valid(pfn)) return NULL;
--
2.30.2