From 95e1ce5bdce1b75e65dabb8f09f877879367c572 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Wed, 8 Apr 2015 09:44:24 +1000
Subject: [PATCH] page-flags: define behavior of LRU-related flags on compound
 pages

Only head pages are ever on LRU. Let's use HEAD policy to avoid any
confusion for all LRU-related flags.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/page-flags.h | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index df2493860821..bdb0d0e226c4 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -271,13 +271,14 @@ static inline struct page *compound_head_fast(struct page *page)
 
 __PAGEFLAG(Locked, locked, NO_TAIL)
 PAGEFLAG(Error, error, NO_COMPOUND) TESTCLEARFLAG(Error, error, NO_COMPOUND)
-PAGEFLAG(Referenced, referenced, ANY) TESTCLEARFLAG(Referenced, referenced, ANY)
-	__SETPAGEFLAG(Referenced, referenced, ANY)
+PAGEFLAG(Referenced, referenced, HEAD)
+	TESTCLEARFLAG(Referenced, referenced, HEAD)
+	__SETPAGEFLAG(Referenced, referenced, HEAD)
 PAGEFLAG(Dirty, dirty, HEAD) TESTSCFLAG(Dirty, dirty, HEAD)
 	__CLEARPAGEFLAG(Dirty, dirty, HEAD)
-PAGEFLAG(LRU, lru, ANY) __CLEARPAGEFLAG(LRU, lru, ANY)
-PAGEFLAG(Active, active, ANY) __CLEARPAGEFLAG(Active, active, ANY)
-	TESTCLEARFLAG(Active, active, ANY)
+PAGEFLAG(LRU, lru, HEAD) __CLEARPAGEFLAG(LRU, lru, HEAD)
+PAGEFLAG(Active, active, HEAD) __CLEARPAGEFLAG(Active, active, HEAD)
+	TESTCLEARFLAG(Active, active, HEAD)
 __PAGEFLAG(Slab, slab, ANY)
 PAGEFLAG(Checked, checked, NO_COMPOUND) /* Used by some filesystems */
 PAGEFLAG(Pinned, pinned, ANY) TESTSCFLAG(Pinned, pinned, ANY)	/* Xen */
@@ -331,9 +332,9 @@ PAGEFLAG(SwapCache, swapcache, ANY)
 PAGEFLAG_FALSE(SwapCache)
 #endif
 
-PAGEFLAG(Unevictable, unevictable, ANY)
-	__CLEARPAGEFLAG(Unevictable, unevictable, ANY)
-	TESTCLEARFLAG(Unevictable, unevictable, ANY)
+PAGEFLAG(Unevictable, unevictable, HEAD)
+	__CLEARPAGEFLAG(Unevictable, unevictable, HEAD)
+	TESTCLEARFLAG(Unevictable, unevictable, HEAD)
 
 #ifdef CONFIG_MMU
 PAGEFLAG(Mlocked, mlocked, ANY) __CLEARPAGEFLAG(Mlocked, mlocked, ANY)
-- 
2.39.5