x86/mm/numa: Fix 32-bit kernel NUMA boot

When booting a 32-bit x86 kernel on a NUMA machine, node data
cannot be allocated from local node if the account of memory for
node 0 covers the low memory space entirely:

  [    0.000000] Initmem setup node 0 [mem 0x00000000-0x83fffffff]
  [    0.000000]   NODE_DATA [mem 0x367ed000-0x367edfff]
  [    0.000000] Initmem setup node 1 [mem 0x840000000-0xfffffffff]
  [    0.000000] Cannot find 4096 bytes in node 1
  [    0.000000] 64664MB HIGHMEM available.
  [    0.000000] 871MB LOWMEM available.

To fix this issue, node data is allowed to be allocated from
other nodes if the memory of local node is still not mapped. The
expected result looks like this:

  [    0.000000] Initmem setup node 0 [mem 0x00000000-0x83fffffff]
  [    0.000000]   NODE_DATA [mem 0x367ed000-0x367edfff]
  [    0.000000] Initmem setup node 1 [mem 0x840000000-0xfffffffff]
  [    0.000000]   NODE_DATA [mem 0x367ec000-0x367ecfff]
  [    0.000000]     NODE_DATA(1) on node 0
  [    0.000000] 64664MB HIGHMEM available.
  [    0.000000] 871MB LOWMEM available.

Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Cc: <andi@firstfloor.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1386303510-18574-1-git-send-email-jia.zhang@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 24aec58d6afdf4ec75390f15413ed26cb47653e8..c85da7bb6b603cf2cab624835ea2d6459958ce5b 100644 (file)
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -211,9 +211,13 @@ static void __init setup_node_data(int nid, u64 start, u64 end)
         */
        nd_pa = memblock_alloc_nid(nd_size, SMP_CACHE_BYTES, nid);
        if (!nd_pa) {
-               pr_err("Cannot find %zu bytes in node %d\n",
-                      nd_size, nid);
-               return;
+               nd_pa = __memblock_alloc_base(nd_size, SMP_CACHE_BYTES,
+                                             MEMBLOCK_ALLOC_ACCESSIBLE);
+               if (!nd_pa) {
+                       pr_err("Cannot find %zu bytes in node %d\n",
+                              nd_size, nid);
+                       return;
+               }
        }
        nd = __va(nd_pa);