pageflags: use an enum for the flags
Use an enum to ease the maintenance of page flags. This is going to change
the numbering from 0 to 18.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index b5b30f1..d669715 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -67,35 +67,29 @@
* FLAGS_RESERVED which defines the width of the fields section
* (see linux/mmzone.h). New flags must _not_ overlap with this area.
*/
-#define PG_locked 0 /* Page is locked. Don't touch. */
-#define PG_error 1
-#define PG_referenced 2
-#define PG_uptodate 3
-
-#define PG_dirty 4
-#define PG_lru 5
-#define PG_active 6
-#define PG_slab 7 /* slab debug (Suparna wants this) */
-
-#define PG_owner_priv_1 8 /* Owner use. If pagecache, fs may use*/
-#define PG_arch_1 9
-#define PG_reserved 10
-#define PG_private 11 /* If pagecache, has fs-private data */
-
-#define PG_writeback 12 /* Page is under writeback */
-#define PG_compound 14 /* Part of a compound page */
-#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
-
-#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
-#define PG_reclaim 17 /* To be reclaimed asap */
-#define PG_buddy 19 /* Page is free, on buddy lists */
-
-/* PG_readahead is only used for file reads; PG_reclaim is only for writes */
-#define PG_readahead PG_reclaim /* Reminder to do async read-ahead */
-
-/* PG_owner_priv_1 users should have descriptive aliases */
-#define PG_checked PG_owner_priv_1 /* Used by some filesystems */
-#define PG_pinned PG_owner_priv_1 /* Xen pinned pagetable */
+enum pageflags {
+ PG_locked, /* Page is locked. Don't touch. */
+ PG_error,
+ PG_referenced,
+ PG_uptodate,
+ PG_dirty,
+ PG_lru,
+ PG_active,
+ PG_slab,
+ PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
+ PG_checked = PG_owner_priv_1, /* Used by some filesystems */
+ PG_pinned = PG_owner_priv_1, /* Xen pinned pagetable */
+ PG_arch_1,
+ PG_reserved,
+ PG_private, /* If pagecache, has fs-private data */
+ PG_writeback, /* Page is under writeback */
+ PG_compound, /* A compound page */
+ PG_swapcache, /* Swap page: swp_entry_t in private */
+ PG_mappedtodisk, /* Has blocks allocated on-disk */
+ PG_reclaim, /* To be reclaimed asap */
+ /* PG_readahead is only used for file reads; PG_reclaim is only for writes */
+ PG_readahead = PG_reclaim, /* Reminder to do async read-ahead */
+ PG_buddy, /* Page is free, on buddy lists */
#if (BITS_PER_LONG > 32)
/*
@@ -105,8 +99,10 @@
* 64 bit | FIELDS | ?????? FLAGS |
* 63 32 0
*/
-#define PG_uncached 31 /* Page has been mapped as uncached */
+ PG_uncached = 31, /* Page has been mapped as uncached */
#endif
+ NR_PAGEFLAGS
+};
/*
* Manipulation of page state flags