mm: use two zonelist that are filtered by GFP mask
Currently a node has two sets of zonelists, one for each zone type in the
system and a second set for GFP_THISNODE allocations. Based on the zones
allowed by a gfp mask, one of these zonelists is selected. All of these
zonelists consume memory and occupy cache lines.
This patch replaces the multiple zonelists per-node with two zonelists. The
first contains all populated zones in the system, ordered by distance, for
fallback allocations when the target/preferred node has no free pages. The
second contains all populated zones in the node suitable for GFP_THISNODE
allocations.
An iterator macro is introduced called for_each_zone_zonelist() that interates
through each zone allowed by the GFP flags in the selected zonelist.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slub.c b/mm/slub.c
index 19ebbfb..80d20cc 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1285,6 +1285,8 @@
#ifdef CONFIG_NUMA
struct zonelist *zonelist;
struct zone **z;
+ struct zone *zone;
+ enum zone_type high_zoneidx = gfp_zone(flags);
struct page *page;
/*
@@ -1310,12 +1312,12 @@
return NULL;
zonelist = node_zonelist(slab_node(current->mempolicy), flags);
- for (z = zonelist->zones; *z; z++) {
+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
struct kmem_cache_node *n;
- n = get_node(s, zone_to_nid(*z));
+ n = get_node(s, zone_to_nid(zone));
- if (n && cpuset_zone_allowed_hardwall(*z, flags) &&
+ if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
n->nr_partial > MIN_PARTIAL) {
page = get_partial_node(n);
if (page)