[PATCH v4 05/25] mm: Add put_folio
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2021-03-05 04:19:34
Also in:
linux-mm, lkml
Subsystem:
memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
If we know we have a folio, we can call put_folio() instead of put_page() and save the overhead of calling compound_head(). Also skips the devmap checks. This commit looks like it should be a no-op, but actually saves 1714 bytes of text with the distro-derived config that I'm testing. Some functions grow a little while others shrink. I presume the compiler is making different inlining decisions. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> --- include/linux/mm.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ecfe202aa4ec..30fd431b1b05 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -1205,9 +1205,15 @@ static inline __must_check bool try_get_page(struct page *page) return true; } +static inline void put_folio(struct folio *folio) +{ + if (put_page_testzero(&folio->page)) + __put_page(&folio->page); +} + static inline void put_page(struct page *page) { - page = compound_head(page); + struct folio *folio = page_folio(page); /* * For devmap managed pages we need to catch refcount transition from
@@ -1215,13 +1221,12 @@ static inline void put_page(struct page *page) * need to inform the device driver through callback. See * include/linux/memremap.h and HMM for details. */ - if (page_is_devmap_managed(page)) { - put_devmap_managed_page(page); + if (page_is_devmap_managed(&folio->page)) { + put_devmap_managed_page(&folio->page); return; } - if (put_page_testzero(page)) - __put_page(page); + put_folio(folio); } /*
--
2.30.0