mm: filter based on a nodemask as well as a gfp_mask

The MPOL_BIND policy creates a zonelist that is used for allocations
controlled by that mempolicy.  As the per-node zonelist is already being
filtered based on a zone id, this patch adds a version of __alloc_pages() that
takes a nodemask for further filtering.  This eliminates the need for
MPOL_BIND to create a custom zonelist.

A positive benefit of this is that allocations using MPOL_BIND now use the
local node's distance-ordered zonelist instead of a custom node-id-ordered
zonelist.  I.e., pages will be allocated from the closest allowed node with
available memory.

[Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework]
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: 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>

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index ac84cd13075d..7d51e649b19a 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -360,16 +360,17 @@ void invalidate_bdev(struct block_device *bdev)
  */
 static void free_more_memory(void)
 {
-        struct zoneref *zrefs;
+        struct zone *zone;
         int nid;
 
         wakeup_pdflush(1024);
         yield();
 
         for_each_online_node(nid) {
-                zrefs = first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
-                                                gfp_zone(GFP_NOFS));
-                if (zrefs->zone)
+                (void)first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
+                                                gfp_zone(GFP_NOFS), NULL,
+                                                &zone);
+                if (zone)
                         try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
                                                 GFP_NOFS);
         }