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authorChristoph Lameter <clameter@sgi.com>2008-04-28 02:12:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:21 -0700
commit9223b4190fa1297a59f292f3419fc0285321d0ea (patch)
treec6fbbc6b4c35916232e95686194eea1bd9de7377 /include
parente26831814998cee8e6d9f0a9854cb46c516f5547 (diff)
pageflags: get rid of FLAGS_RESERVED
NR_PAGEFLAGS specifies the number of page flags we are using. From that we can calculate the number of bits leftover that can be used for zone, node (and maybe the sections id). There is no need anymore for FLAGS_RESERVED if we use NR_PAGEFLAGS. Use the new methods to make NR_PAGEFLAGS available via the preprocessor. NR_PAGEFLAGS is used to calculate field boundaries in the page flags fields. These field widths have to be available to the preprocessor. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: David Miller <davem@davemloft.net> 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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mm.h6
-rw-r--r--include/linux/mmzone.h19
-rw-r--r--include/linux/page-flags.h19
3 files changed, 15 insertions, 29 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 4f3c1b2f44de..526f810367d9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -407,7 +407,7 @@ static inline void set_compound_order(struct page *page, unsigned long order)
#define ZONES_WIDTH ZONES_SHIFT
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED
+#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
#define NODES_WIDTH NODES_SHIFT
#else
#ifdef CONFIG_SPARSEMEM_VMEMMAP
@@ -455,8 +455,8 @@ static inline void set_compound_order(struct page *page, unsigned long order)
#define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
-#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
-#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
+#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
+#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
#endif
#define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0aece6d8937e..c7a51dac441d 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -820,25 +820,6 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
#include <asm/sparsemem.h>
#endif
-#if BITS_PER_LONG == 32
-/*
- * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
- * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
- */
-#define FLAGS_RESERVED 9
-
-#elif BITS_PER_LONG == 64
-/*
- * with 64 bit flags field, there's plenty of room.
- */
-#define FLAGS_RESERVED 32
-
-#else
-
-#error BITS_PER_LONG not defined
-
-#endif
-
#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
!defined(CONFIG_ARCH_POPULATES_NODE_MAP)
static inline unsigned long early_pfn_to_nid(unsigned long pfn)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d66971530caa..00e55e23b777 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -6,7 +6,10 @@
#define PAGE_FLAGS_H
#include <linux/types.h>
+#ifndef __GENERATING_BOUNDS_H
#include <linux/mm_types.h>
+#include <linux/bounds.h>
+#endif /* !__GENERATING_BOUNDS_H */
/*
* Various page->flags bits:
@@ -59,13 +62,12 @@
* extends from the high bits downwards.
*
* | FIELD | ... | FLAGS |
- * N-1 ^ 0
- * (N-FLAGS_RESERVED)
+ * N-1 ^ 0
+ * (NR_PAGEFLAGS)
*
- * The fields area is reserved for fields mapping zone, node and SPARSEMEM
- * section. The boundry between these two areas is defined by
- * FLAGS_RESERVED which defines the width of the fields section
- * (see linux/mmzone.h). New flags must _not_ overlap with this area.
+ * The fields area is reserved for fields mapping zone, node (for NUMA) and
+ * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
+ * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
*/
enum pageflags {
PG_locked, /* Page is locked. Don't touch. */
@@ -101,9 +103,11 @@ enum pageflags {
*/
PG_uncached = 31, /* Page has been mapped as uncached */
#endif
- NR_PAGEFLAGS
+ __NR_PAGEFLAGS
};
+#ifndef __GENERATING_BOUNDS_H
+
/*
* Manipulation of page state flags
*/
@@ -304,4 +308,5 @@ static inline void set_page_writeback(struct page *page)
test_set_page_writeback(page);
}
+#endif /* !__GENERATING_BOUNDS_H */
#endif /* PAGE_FLAGS_H */