The patch titled
linearly index zone->node_zonelists[]
has been added to the -mm tree. Its filename is
linearly-index-zone-node_zonelists.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: linearly index zone->node_zonelists[]
From: Christoph Lameter <clameter@xxxxxxx>
I wonder why we need this bitmask indexing into zone->node_zonelists[]?
We always start with the highest zone and then include all lower zones
if we build zonelists.
Are there really cases where we need allocation from ZONE_DMA or
ZONE_HIGHMEM but not ZONE_NORMAL? It seems that the current implementation
of highest_zone() makes that already impossible.
If we go linear on the index then gfp_zone() == highest_zone() and a lot
of definitions fall by the wayside.
We can now revert back to the use of gfp_zone() in mempolicy.c ;-)
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/gfp.h | 12 ---------
include/linux/mmzone.h | 52 +++------------------------------------
mm/mempolicy.c | 2 -
mm/page_alloc.c | 27 ++++++++------------
4 files changed, 18 insertions(+), 75 deletions(-)
diff -puN include/linux/gfp.h~linearly-index-zone-node_zonelists include/linux/gfp.h
--- a/include/linux/gfp.h~linearly-index-zone-node_zonelists
+++ a/include/linux/gfp.h
@@ -12,9 +12,6 @@ struct vm_area_struct;
*
* Zone modifiers (see linux/mmzone.h - low three bits)
*
- * These may be masked by GFP_ZONEMASK to make allocations with this bit
- * set fall back to ZONE_NORMAL.
- *
* Do not put any conditional on these. If necessary modify the definitions
* without the underscores and use the consistently. The definitions here may
* be used in bit comparisons.
@@ -78,14 +75,7 @@ struct vm_area_struct;
#define GFP_DMA32 __GFP_DMA32
-static inline int gfp_zone(gfp_t gfp)
-{
- int zone = GFP_ZONEMASK & (__force int) gfp;
- BUG_ON(zone >= GFP_ZONETYPES);
- return zone;
-}
-
-static inline enum zone_type highest_zone(gfp_t flags)
+static inline enum zone_type gfp_zone(gfp_t flags)
{
if (flags & __GFP_DMA)
return ZONE_DMA;
diff -puN include/linux/mmzone.h~linearly-index-zone-node_zonelists include/linux/mmzone.h
--- a/include/linux/mmzone.h~linearly-index-zone-node_zonelists
+++ a/include/linux/mmzone.h
@@ -136,60 +136,18 @@ enum zone_type {
MAX_NR_ZONES
};
-
/*
* When a memory allocation must conform to specific limitations (such
* as being suitable for DMA) the caller will pass in hints to the
* allocator in the gfp_mask, in the zone modifier bits. These bits
* are used to select a priority ordered list of memory zones which
- * match the requested limits. GFP_ZONEMASK defines which bits within
- * the gfp_mask should be considered as zone modifiers. Each valid
- * combination of the zone modifier bits has a corresponding list
- * of zones (in node_zonelists). Thus for two zone modifiers there
- * will be a maximum of 4 (2 ** 2) zonelists, for 3 modifiers there will
- * be 8 (2 ** 3) zonelists. GFP_ZONETYPES defines the number of possible
- * combinations of zone modifiers in "zone modifier space".
- *
- * As an optimisation any zone modifier bits which are only valid when
- * no other zone modifier bits are set (loners) should be placed in
- * the highest order bits of this field. This allows us to reduce the
- * extent of the zonelists thus saving space. For example in the case
- * of three zone modifier bits, we could require up to eight zonelists.
- * If the left most zone modifier is a "loner" then the highest valid
- * zonelist would be four allowing us to allocate only five zonelists.
- * Use the first form for GFP_ZONETYPES when the left most bit is not
- * a "loner", otherwise use the second.
- *
- * NOTE! Make sure this matches the zones in <linux/gfp.h>
+ * match the requested limits. See gfp_zone() in include/linux/gfp.h
*/
-#ifdef CONFIG_ZONE_DMA32
-
-#ifdef CONFIG_HIGHMEM
-#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */
-#define GFP_ZONEMASK 0x07
-#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
-#else
-#define GFP_ZONETYPES ((0x07 + 1) / 2 + 1) /* Loner */
-/* Mask __GFP_HIGHMEM */
-#define GFP_ZONEMASK 0x05
-#define ZONES_SHIFT 2
-#endif
-
+#if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
+#define ZONES_SHIFT 1
#else
-#ifdef CONFIG_HIGHMEM
-
-#define GFP_ZONEMASK 0x03
-#define ZONES_SHIFT 2
-#define GFP_ZONETYPES 3
-
-#else
-
-#define GFP_ZONEMASK 0x01
-#define ZONES_SHIFT 1
-#define GFP_ZONETYPES 2
-
-#endif
+#define ZONES_SHIFT 2
#endif
struct zone {
@@ -359,7 +317,7 @@ struct zonelist {
struct bootmem_data;
typedef struct pglist_data {
struct zone node_zones[MAX_NR_ZONES];
- struct zonelist node_zonelists[GFP_ZONETYPES];
+ struct zonelist node_zonelists[MAX_NR_ZONES];
int nr_zones;
#ifdef CONFIG_FLAT_NODE_MEM_MAP
struct page *node_mem_map;
diff -puN mm/mempolicy.c~linearly-index-zone-node_zonelists mm/mempolicy.c
--- a/mm/mempolicy.c~linearly-index-zone-node_zonelists
+++ a/mm/mempolicy.c
@@ -1097,7 +1097,7 @@ static struct zonelist *zonelist_policy(
case MPOL_BIND:
/* Lower zones don't get a policy applied */
/* Careful: current->mems_allowed might have moved */
- if (highest_zone(gfp) >= policy_zone)
+ if (gfp_zone(gfp) >= policy_zone)
if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
return policy->v.zonelist;
/*FALL THROUGH*/
diff -puN mm/page_alloc.c~linearly-index-zone-node_zonelists mm/page_alloc.c
--- a/mm/page_alloc.c~linearly-index-zone-node_zonelists
+++ a/mm/page_alloc.c
@@ -1444,14 +1444,14 @@ static int __meminit find_next_best_node
static void __meminit build_zonelists(pg_data_t *pgdat)
{
- int i, j, node, local_node;
+ int j, node, local_node;
+ enum zone_type i;
int prev_node, load;
struct zonelist *zonelist;
nodemask_t used_mask;
- enum zone_type k;
/* initialize zonelists */
- for (i = 0; i < GFP_ZONETYPES; i++) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
zonelist = pgdat->node_zonelists + i;
zonelist->zones[0] = NULL;
}
@@ -1481,13 +1481,11 @@ static void __meminit build_zonelists(pg
node_load[node] += load;
prev_node = node;
load--;
- for (i = 0; i < GFP_ZONETYPES; i++) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
zonelist = pgdat->node_zonelists + i;
for (j = 0; zonelist->zones[j] != NULL; j++);
- k = highest_zone(i);
-
- j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
zonelist->zones[j] = NULL;
}
}
@@ -1497,19 +1495,16 @@ static void __meminit build_zonelists(pg
static void __meminit build_zonelists(pg_data_t *pgdat)
{
- int i, node, local_node;
- enum zone_type k;
- enum zone_type j;
+ int node, local_node;
+ enum zone_type i,j;
local_node = pgdat->node_id;
- for (i = 0; i < GFP_ZONETYPES; i++) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
struct zonelist *zonelist;
zonelist = pgdat->node_zonelists + i;
- j = 0;
- k = highest_zone(i);
- j = build_zonelists_node(pgdat, zonelist, j, k);
+ j = build_zonelists_node(pgdat, zonelist, 0, i);
/*
* Now we build the zonelist so that it contains the zones
* of all the other nodes.
@@ -1521,12 +1516,12 @@ static void __meminit build_zonelists(pg
for (node = local_node + 1; node < MAX_NUMNODES; node++) {
if (!node_online(node))
continue;
- j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
}
for (node = 0; node < local_node; node++) {
if (!node_online(node))
continue;
- j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
}
zonelist->zones[j] = NULL;
_
Patches currently in -mm which might be from clameter@xxxxxxx are
reduce-max_nr_zones-remove-two-strange-uses-of-max_nr_zones.patch
reduce-max_nr_zones-fix-max_nr_zones-array-initializations.patch
reduce-max_nr_zones-make-display-of-highmem-counters-conditional-on-config_highmem.patch
reduce-max_nr_zones-make-display-of-highmem-counters-conditional-on-config_highmem-tidy.patch
reduce-max_nr_zones-move-highmem-counters-into-highmemc-h.patch
reduce-max_nr_zones-move-highmem-counters-into-highmemc-h-fix.patch
reduce-max_nr_zones-page-allocator-zone_highmem-cleanup.patch
reduce-max_nr_zones-use-enum-to-define-zones-reformat-and-comment.patch
reduce-max_nr_zones-use-enum-to-define-zones-reformat-and-comment-cleanup.patch
reduce-max_nr_zones-make-zone_dma32-optional.patch
reduce-max_nr_zones-make-zone_highmem-optional.patch
reduce-max_nr_zones-make-zone_highmem-optional-fix.patch
reduce-max_nr_zones-make-zone_highmem-optional-fix-fix.patch
reduce-max_nr_zones-remove-display-of-counters-for-unconfigured-zones.patch
reduce-max_nr_zones-fix-i386-srat-check-for-max_nr_zones.patch
mempolicies-fix-policy_zone-check.patch
apply-type-enum-zone_type.patch
linearly-index-zone-node_zonelists.patch
slab-respect-architecture-and-caller-mandated-alignment.patch
slab-optimize-kmalloc_node-the-same-way-as-kmalloc.patch
x86-implement-always-locked-bit-ops-for-memory-shared-with-an-smp-hypervisor.patch
reduce-max_nr_zones-swap_prefetch-remove-incorrect-use-of-zone_highmem.patch
apply-type-enum-zone_type-readahead.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
