x86, mm: Fix node_possible_map logic

Recently there were some changes to the meaning of node_possible_map,
and it is quite strange:

- the node without memory would be set in node_possible_map
- but some node with less NODE_MIN_SIZE will be kicked out of node_possible_map.

fix it by adding strict_setup_node_bootmem().

Also, remove unparse_node().

so result will be:

1. cpu_to_node() will return online node only (nearest one)
2. apicid_to_node() still returns the node that could be not online but is set
   in node_possible_map.
3. node_possible_map will include nodes that mem on it are less NODE_MIN_SIZE

v2: after move_cpus_to_node change.

[ Impact: get node_possible_map right ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <4A0C49BE.6080800@kernel.org>
[ v3: various small cleanups and comment clarifications ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 3 deletions

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index a6a93c395231..459913beac71 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -179,18 +179,25 @@ static void * __init early_node_mem(int nodeid, unsigned long start,
 }
 
 /* Initialize bootmem allocator for a node */
-void __init setup_node_bootmem(int nodeid, unsigned long start,
-                               unsigned long end)
+void __init
+setup_node_bootmem(int nodeid, unsigned long start, unsigned long end)
 {
         unsigned long start_pfn, last_pfn, bootmap_pages, bootmap_size;
+        const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
         unsigned long bootmap_start, nodedata_phys;
         void *bootmap;
-        const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
         int nid;
 
         if (!end)
                 return;
 
+        /*
+         * Don't confuse VM with a node that doesn't have the
+         * minimum amount of memory:
+         */
+        if (end && (end - start) < NODE_MIN_SIZE)
+                return;
+
         start = roundup(start, ZONE_ALIGN);
 
         printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid,