From: Zi Yan <ziy@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
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
