The patch titled
pageflags: get rid of FLAGS_RESERVED
has been added to the -mm tree. Its filename is
pageflags-get-rid-of-flags_reserved.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: pageflags: get rid of FLAGS_RESERVED
From: Christoph Lameter <clameter@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 6 +++---
include/linux/mmzone.h | 19 -------------------
include/linux/page-flags.h | 20 +++++++++++++-------
kernel/bounds.c | 1 +
4 files changed, 17 insertions(+), 29 deletions(-)
diff -puN include/linux/mm.h~pageflags-get-rid-of-flags_reserved include/linux/mm.h
--- a/include/linux/mm.h~pageflags-get-rid-of-flags_reserved
+++ a/include/linux/mm.h
@@ -398,7 +398,7 @@ static inline void set_compound_order(st
#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
@@ -446,8 +446,8 @@ static inline void set_compound_order(st
#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 -puN include/linux/mmzone.h~pageflags-get-rid-of-flags_reserved include/linux/mmzone.h
--- a/include/linux/mmzone.h~pageflags-get-rid-of-flags_reserved
+++ a/include/linux/mmzone.h
@@ -839,25 +839,6 @@ static inline struct zoneref *next_zones
#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)
#define early_pfn_to_nid(nid) (0UL)
diff -puN include/linux/page-flags.h~pageflags-get-rid-of-flags_reserved include/linux/page-flags.h
--- a/include/linux/page-flags.h~pageflags-get-rid-of-flags_reserved
+++ a/include/linux/page-flags.h
@@ -59,13 +59,12 @@
* 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 +100,16 @@ enum pageflags {
*/
PG_uncached = 31, /* Page has been mapped as uncached */
#endif
- NR_PAGEFLAGS
+ __NR_PAGEFLAGS
};
+#ifndef __GENERATING_BOUNDS_H
+#include <linux/bounds.h>
+#else
+/* Dummy for use during bounds.h generation */
+#define NR_PAGEFLAGS 1
+#endif
+
/*
* Manipulation of page state flags
*/
diff -puN kernel/bounds.c~pageflags-get-rid-of-flags_reserved kernel/bounds.c
--- a/kernel/bounds.c~pageflags-get-rid-of-flags_reserved
+++ a/kernel/bounds.c
@@ -15,5 +15,6 @@
void foo(void)
{
/* The enum constants to put into include/linux/bounds.h */
+ DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
/* End of constants */
}
_
Patches currently in -mm which might be from clameter@xxxxxxx are
fix-mempolicy-reference-counting-bugs.patch
ntfs-fix-nommu-build.patch
git-unionfs.patch
git-slub.patch
x86-cast-cmpxchg-and-cmpxchg_local-result-for-386-and-486.patch
remove-set_migrateflags.patch
mm-use-zonelists-instead-of-zones-when-direct-reclaiming-pages.patch
mm-introduce-node_zonelist-for-accessing-the-zonelist-for-a-gfp-mask.patch
mm-remember-what-the-preferred-zone-is-for-zone_statistics.patch
mm-use-two-zonelist-that-are-filtered-by-gfp-mask.patch
mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-doc-fixes.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-make-dequeue_huge_page_vma-obey-mpol_bind-nodemask.patch
mm-filter-based-on-a-nodemask-as-well-as-a-gfp_mask-make-dequeue_huge_page_vma-obey-mpol_bind-nodemask-rework.patch
mm-move-cache_line_size-to-linux-cacheh.patch
mempolicy-convert-mpol-constants-to-enum.patch
mempolicy-support-optional-mode-flags.patch
mempolicy-add-mpol_f_static_nodes-flag.patch
mempolicy-add-bitmap_onto-and-bitmap_fold-operations.patch
mempolicy-add-mpol_f_relative_nodes-flag.patch
mempolicy-update-numa-memory-policy-documentation.patch
mempolicy-move-rebind-functions.patch
mempolicy-create-mempolicy_operations-structure.patch
mempolicy-create-mempolicy_operations-structure-fix.patch
mempolicy-small-header-file-cleanup.patch
sparsemem-vmemmap-does-not-need-section-bits.patch
kbuild-create-a-way-to-create-preprocessor-constants-from-c-expressions.patch
pageflags-use-an-enum-for-the-flags.patch
pageflags-get-rid-of-flags_reserved.patch
pageflags-introduce-macros-to-generate-page-flag-functions.patch
pageflags-convert-to-the-use-of-new-macros.patch
pageflags-use-proper-page-flag-functions-in-xen.patch
pageflags-eliminate-pg_xxx-aliases.patch
get-rid-of-__zone_count.patch
reiser4.patch
reiser4-portion-of-zero_user-cleanup-patch.patch
page-owner-tracking-leak-detector.patch
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