Memoryless nodes: Fix GFP_THISNODE behavior

GFP_THISNODE checks that the zone selected is within the pgdat (node) of the
first zone of a nodelist.  That only works if the node has memory.  A
memoryless node will have its first node on another pgdat (node).

GFP_THISNODE currently will return simply memory on the first pgdat.  Thus it
is returning memory on other nodes.  GFP_THISNODE should fail if there is no
local memory on a node.

Add a new set of zonelists for each node that only contain the nodes that
belong to the zones itself so that no fallback is possible.

Then modify gfp_type to pickup the right zone based on the presence of
__GFP_THISNODE.

Drop the existing GFP_THISNODE checks from the page_allocators hot path.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Tested-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Bob Picco <bob.picco@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 25 insertions, 6 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index bc68dd9a6d41..12a90a191c11 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -98,22 +98,29 @@ struct vm_area_struct;
 
 static inline enum zone_type gfp_zone(gfp_t flags)
 {
+	int base = 0;
+
+#ifdef CONFIG_NUMA
+	if (flags & __GFP_THISNODE)
+		base = MAX_NR_ZONES;
+#endif
+
 #ifdef CONFIG_ZONE_DMA
 	if (flags & __GFP_DMA)
-		return ZONE_DMA;
+		return base + ZONE_DMA;
 #endif
 #ifdef CONFIG_ZONE_DMA32
 	if (flags & __GFP_DMA32)
-		return ZONE_DMA32;
+		return base + ZONE_DMA32;
 #endif
 	if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
 			(__GFP_HIGHMEM | __GFP_MOVABLE))
-		return ZONE_MOVABLE;
+		return base + ZONE_MOVABLE;
 #ifdef CONFIG_HIGHMEM
 	if (flags & __GFP_HIGHMEM)
-		return ZONE_HIGHMEM;
+		return base + ZONE_HIGHMEM;
 #endif
-	return ZONE_NORMAL;
+	return base + ZONE_NORMAL;
 }
 
 /*
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index f21e5951038b..f6167f2fd7fb 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -324,6 +324,17 @@ struct zone {
 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
 
 #ifdef CONFIG_NUMA
+
+/*
+ * The NUMA zonelists are doubled becausse we need zonelists that restrict the
+ * allocations to a single node for GFP_THISNODE.
+ *
+ * [0 .. MAX_NR_ZONES -1] 		: Zonelists with fallback
+ * [MAZ_NR_ZONES ... MAZ_ZONELISTS -1]  : No fallback (GFP_THISNODE)
+ */
+#define MAX_ZONELISTS (2 * MAX_NR_ZONES)
+
+
 /*
  * We cache key information from each zonelist for smaller cache
  * footprint when scanning for free pages in get_page_from_freelist().
@@ -389,6 +400,7 @@ struct zonelist_cache {
 	unsigned long last_full_zap;		/* when last zap'd (jiffies) */
 };
 #else
+#define MAX_ZONELISTS MAX_NR_ZONES
 struct zonelist_cache;
 #endif
 
@@ -455,7 +467,7 @@ extern struct page *mem_map;
 struct bootmem_data;
 typedef struct pglist_data {
 	struct zone node_zones[MAX_NR_ZONES];
-	struct zonelist node_zonelists[MAX_NR_ZONES];
+	struct zonelist node_zonelists[MAX_ZONELISTS];
 	int nr_zones;
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 	struct page *node_mem_map;