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/fs/buffer.c b/fs/buffer.c
index 7135849..9b5434a 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -360,16 +360,18 @@
*/
static void free_more_memory(void)
{
- struct zonelist *zonelist;
+ struct zone **zones;
int nid;
wakeup_pdflush(1024);
yield();
for_each_online_node(nid) {
- zonelist = node_zonelist(nid, GFP_NOFS);
- if (zonelist->zones[0])
- try_to_free_pages(zonelist, 0, GFP_NOFS);
+ zones = first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
+ gfp_zone(GFP_NOFS));
+ if (*zones)
+ try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
+ GFP_NOFS);
}
}