From 013e896373fc53f3d3c039364a25ccbd1fc0729a Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Thu, 14 Jul 2011 12:48:14 -0500 Subject: [PATCH] Avoid duplicate _count variables in page_struct Restructure the union / struct cascade in struct page so that we only have one definition of _count. Tested-by: Hugh Dickins Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- include/linux/mm_types.h | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3d76a433d52f..774b8952deb4 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -49,30 +49,31 @@ struct page { * see PAGE_MAPPING_ANON below. */ /* Second double word */ - union { - struct { + struct { + union { pgoff_t index; /* Our offset within mapping. */ - atomic_t _mapcount; /* Count of ptes mapped in mms, + void *freelist; /* slub first free object */ + }; + + union { + /* Used for cmpxchg_double in slub */ + unsigned long counters; + + struct { + + union { + atomic_t _mapcount; /* Count of ptes mapped in mms, * to show when page is mapped * & limit reverse map searches. */ - atomic_t _count; /* Usage count, see below. */ - }; - struct { /* SLUB cmpxchg_double area */ - void *freelist; - union { - unsigned long counters; - struct { - unsigned inuse:16; - unsigned objects:15; - unsigned frozen:1; - /* - * Kernel may make use of this field even when slub - * uses the rest of the double word! - */ - atomic_t _count; + struct { + unsigned inuse:16; + unsigned objects:15; + unsigned frozen:1; + }; }; + atomic_t _count; /* Usage count, see below. */ }; }; };