From 19655d3487001d7df0e10e9cbfc27c758b77c2b5 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 25 Sep 2006 23:31:19 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 --git a/include/linux/gfp.h b/include/linux/gfp.h index a0992d392d7..63ab88a36f3 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 76d33e68859..7fe317164b7 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 + * 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 7da4142ce96..c3429a710ab 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 9c44b9a39d3..208a6b03aa7 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; -- 2.20.1