On Thu, Oct 24, 2019 at 01:05:04AM +0800, Yang Shi wrote: > + return map_count >= 0 && > + map_count == atomic_read(&head[1].compound_mapcount); > } I didn't like Hugh's duplicate definition either. May I suggest: diff --git a/include/linux/mm.h b/include/linux/mm.h index 2f2199a51941..3d0efd937d2b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -695,11 +695,6 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) extern void kvfree(const void *addr); -static inline atomic_t *compound_mapcount_ptr(struct page *page) -{ - return &page[1].compound_mapcount; -} - static inline int compound_mapcount(struct page *page) { VM_BUG_ON_PAGE(!PageCompound(page), page); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 2222fa795284..270aa8fd2800 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -221,6 +221,11 @@ struct page { #endif } _struct_page_alignment; +static inline atomic_t *compound_mapcount_ptr(struct page *page) +{ + return &page[1].compound_mapcount; +} + /* * Used for sizing the vmemmap region on some architectures */