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authorChristoph Lameter <clameter@sgi.com>2006-09-25 23:31:19 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:47 -0700
commit19655d3487001d7df0e10e9cbfc27c758b77c2b5 (patch)
tree8d0aaa216bd32bd64e3a9652fd34d40bdb9d1075
parent2f6726e54a9410e2e4cee864947c05e954051916 (diff)
[PATCH] linearly index zone->node_zonelists[]
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@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/gfp.h12
-rw-r--r--include/linux/mmzone.h52
-rw-r--r--mm/mempolicy.c2
-rw-r--r--mm/page_alloc.c27
4 files changed, 18 insertions, 75 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index a0992d392d79..63ab88a36f39 100644
--- a/include/linux/gfp.h
+++ b/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 --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 76d33e688593..7fe317164b73 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -137,60 +137,18 @@ 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
-
-#else
-#ifdef CONFIG_HIGHMEM
-
-#define GFP_ZONEMASK 0x03
-#define ZONES_SHIFT 2
-#define GFP_ZONETYPES 3
-
+#if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
+#define ZONES_SHIFT 1
#else
-
-#define GFP_ZONEMASK 0x01
-#define ZONES_SHIFT 1
-#define GFP_ZONETYPES 2
-
-#endif
+#define ZONES_SHIFT 2
#endif
struct zone {
@@ -360,7 +318,7 @@ 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 --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7da4142ce960..c3429a710ab1 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1101,7 +1101,7 @@ static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *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 --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9c44b9a39d30..208a6b03aa78 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1444,14 +1444,14 @@ static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask)
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_data_t *pgdat)
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_data_t *pgdat)
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_data_t *pgdat)
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;