From 2be1d71841b7ecfb01ce4c59f6e1d082c3c18a8a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 14 Aug 2020 17:30:40 -0700 Subject: mm: add thp_head This is like compound_head() but compiles away when CONFIG_TRANSPARENT_HUGEPAGE is not enabled. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Reviewed-by: William Kucharski Reviewed-by: Zi Yan Cc: David Hildenbrand Cc: Mike Kravetz Cc: "Kirill A. Shutemov" Link: http://lkml.kernel.org/r/20200629151959.15779-7-willy@infradead.org Signed-off-by: Linus Torvalds --- include/linux/huge_mm.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include') diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 229f986d535a..8a8bc46a2432 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -259,6 +259,15 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud, return NULL; } +/** + * thp_head - Head page of a transparent huge page. + * @page: Any page (tail, head or regular) found in the page cache. + */ +static inline struct page *thp_head(struct page *page) +{ + return compound_head(page); +} + /** * thp_order - Order of a transparent huge page. * @page: Head page of a transparent huge page. @@ -335,6 +344,12 @@ static inline struct list_head *page_deferred_list(struct page *page) #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; }) #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; }) +static inline struct page *thp_head(struct page *page) +{ + VM_BUG_ON_PGFLAGS(PageTail(page), page); + return page; +} + static inline unsigned int thp_order(struct page *page) { VM_BUG_ON_PGFLAGS(PageTail(page), page); -- cgit v1.2.3-59-g8ed1b