linux-kernel - [PATCH v13 01/32] mm: Convert get_page_unless

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Message-Id: <20210712190204.80979-2-willy@infradead.org>
Date:   Mon, 12 Jul 2021 20:01:33 +0100
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     akpm@...ux-foundation.org
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-fsdevel@...r.kernel.org, Christoph Hellwig <hch@....de>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH v13 01/32] mm: Convert get_page_unless_zero() to return bool

atomic_add_unless() returns bool, so remove the widening casts to int
in page_ref_add_unless() and get_page_unless_zero().  This causes gcc
to produce slightly larger code in isolate_migratepages_block(), but
it's not clear that it's worse code.  Net +19 bytes of text.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
Reviewed-by: Christoph Hellwig <hch@....de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 include/linux/mm.h       | 2 +-
 include/linux/page_ref.h | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 57453dba41b9..02851931e958 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -755,7 +755,7 @@ static inline int put_page_testzero(struct page *page)
  * This can be called when MMU is off so it must not access
  * any of the virtual mappings.
  */
-static inline int get_page_unless_zero(struct page *page)
+static inline bool get_page_unless_zero(struct page *page)
 {
 	return page_ref_add_unless(page, 1, 0);
 }
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 7ad46f45df39..3a799de8ad52 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -161,9 +161,9 @@ static inline int page_ref_dec_return(struct page *page)
 	return ret;
 }
 
-static inline int page_ref_add_unless(struct page *page, int nr, int u)
+static inline bool page_ref_add_unless(struct page *page, int nr, int u)
 {
-	int ret = atomic_add_unless(&page->_refcount, nr, u);
+	bool ret = atomic_add_unless(&page->_refcount, nr, u);
 
 	if (page_ref_tracepoint_active(page_ref_mod_unless))
 		__page_ref_mod_unless(page, nr, ret);
-- 
2.30.2