[PATCH] sparsemem base: simple NUMA remap space allocator

Introduce a simple allocator for the NUMA remap space.  This space is very
scarce, used for structures which are best allocated node local.

This mechanism is also used on non-NUMA ia64 systems with a vmem_map to keep
the pgdat->node_mem_map initialized in a consistent place for all
architectures.

Issues:
o alloc_remap takes a node_id where we might expect a pgdat which was intended
  to allow us to allocate the pgdat's using this mechanism; which we do not yet
  do.  Could have alloc_remap_node() and alloc_remap_nid() for this purpose.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 559336de9687..bf1dd8819097 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1936,6 +1936,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat,
 static void __init alloc_node_mem_map(struct pglist_data *pgdat)
 {
         unsigned long size;
+        struct page *map;
 
         /* Skip empty nodes */
         if (!pgdat->node_spanned_pages)
@@ -1944,7 +1945,10 @@ static void __init alloc_node_mem_map(struct pglist_data *pgdat)
         /* ia64 gets its own node_mem_map, before this, without bootmem */
         if (!pgdat->node_mem_map) {
                 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
-                pgdat->node_mem_map = alloc_bootmem_node(pgdat, size);
+                map = alloc_remap(pgdat->node_id, size);
+                if (!map)
+                        map = alloc_bootmem_node(pgdat, size);
+                pgdat->node_mem_map = map;
         }
 #ifndef CONFIG_DISCONTIGMEM
         /*