From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> If THP is disabled, find_subpage() can become a no-op by using hpage_nr_pages() instead of compound_nr(). hpage_nr_pages() embeds a check for PageTail, so we can drop the check here. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> --- include/linux/pagemap.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 68db0ed8535d..fcb4887e65e8 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -343,9 +343,7 @@ static inline struct page *find_subpage(struct page *head, pgoff_t index) if (PageHuge(head)) return head; - VM_BUG_ON_PAGE(PageTail(head), head); - - return head + (index & (compound_nr(head) - 1)); + return head + (index & (hpage_nr_pages(head) - 1)); } struct page *find_get_entry(struct address_space *mapping, pgoff_t offset); -- 2.25.1
