[PATCH -v3] nobootmem/bootmem, x86: Fix 32bit numa system without RAM on Node0

[Yinghai Lu <yinghai@kernel.org>]

on one system without RAM on nod0, got following dump with 32bit numa kernel

early_node_map[4] active PFN ranges
    1: 0x00000010 -> 0x00000099
    1: 0x00000100 -> 0x0007da00
    1: 0x0007e800 -> 0x0007ffa0
    1: 0x0007ffae -> 0x0007ffb0

Subtract (29 early reservations)
  #000 [0000001000 - 0000002000]
  #001 [0000089000 - 000008f000]
  #002 [0000091000 - 0000093500]
  #003 [0000094000 - 0000099000]
  #004 [0000099400 - 0000100000]
  #005 [0000200000 - 0000eb7644]
  #006 [0000eb8000 - 0000ec327c]
  #007 [007c400000 - 007c40e000]
  #008 [007c440000 - 007c44e000]
  #009 [007c480000 - 007c48e000]
  #010 [007c4c0000 - 007c4ce000]
  #011 [007c500000 - 007c50e000]
  #012 [007c540000 - 007c54e000]
  #013 [007c580000 - 007c58e000]
  #014 [007c5c0000 - 007c5ce000]
  #015 [007c674000 - 007cbfe000]
  #016 [007cbfe500 - 007cbfe530]
  #017 [007cbfe540 - 007cbfe5d0]
  #018 [007cbfe600 - 007cbfe620]
  #019 [007cbfe640 - 007cbfe660]
  #020 [007cbfe680 - 007cbfe684]
  #021 [007cbfe6c0 - 007cbfe6c4]
  #022 [007cbfe700 - 007cbfe77e]
  #023 [007cbfe780 - 007cbfe7fe]
  #024 [007cbfe800 - 007cbfec54]
  #025 [007cbfec80 - 007cbfeede]
  #026 [007cbfef00 - 007cbfef2d]
  #027 [007cbfef40 - 007e800000]
  #028 [007e9ca000 - 007ff95000]
(0 free memory ranges)
Initializing HighMem for node 0 (00000000:00000000)
Initializing HighMem for node 1 (00000000:00000000)
Memory: 0k/2096832k available (6662k kernel code, 2096300k reserved, 4829k data, 484k init, 0k highmem)
virtual kernel memory layout:
    fixmap  : 0xff637000 - 0xfffff000   (10016 kB)
    pkmap   : 0xff200000 - 0xff400000   (2048 kB)
    vmalloc : 0xc07b0000 - 0xff1fe000   (1002 MB)
    lowmem  : 0x40000000 - 0xbffb0000   (2047 MB)
      .init : 0x40d39000 - 0x40db2000   ( 484 kB)
      .data : 0x40881924 - 0x40d38e1c   (4829 kB)
      .text : 0x40200000 - 0x40881924   (6662 kB)
Checking if this processor honours the WP bit even in supervisor mode...Ok.
swapper: page allocation failure. order:0, mode:0x0
Pid: 0, comm: swapper Not tainted 2.6.34-rc3-tip-03818-g4b1ea6c-dirty #35
Call Trace:
 [<4087a5dc>] ? printk+0xf/0x11
 [<40286728>] __alloc_pages_nodemask+0x417/0x487
 [<402a9ce1>] new_slab+0xe2/0x1fe
 [<402aa5b2>] kmem_cache_open+0x185/0x358
 [<402abbc0>] T.954+0x1c/0x60
 [<40d52a29>] kmem_cache_init+0x24/0x113
 [<40d39738>] start_kernel+0x166/0x2e4
 [<40d3940e>] ? unknown_bootoption+0x0/0x18e
 [<40d390ce>] i386_start_kernel+0xce/0xd5
Mem-Info:
Node 1 DMA per-cpu:
CPU    0: hi:    0, btch:   1 usd:   0
Node 1 Normal per-cpu:
CPU    0: hi:    0, btch:   1 usd:   0
active_anon:0 inactive_anon:0 isolated_anon:0
 active_file:0 inactive_file:0 isolated_file:0
 unevictable:0 dirty:0 writeback:0 unstable:0
 free:0 slab_reclaimable:0 slab_unreclaimable:0
 mapped:0 shmem:0 pagetables:0 bounce:0

When 32bit numa is used, free_all_bootmem() will still only go over with
node id 0.

If node 0 doesn't have RAM installed, We need to go with node1
because early_node_map still use 1 for all ranges, and ram from node1
become low ram.

Try to use MAX_NUMNODES like 64 numa does.

Also fixes BOOTMEM path by loop bdata_list.
Note: this bug exist before We have NO_BOOTMEM support.

-v3: add more comments, and fix bootmem path too.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 mm/bootmem.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/bootmem.c
===================================================================
--- linux-2.6.orig/mm/bootmem.c
+++ linux-2.6/mm/bootmem.c
@@ -303,9 +303,22 @@ unsigned long __init free_all_bootmem_no
 unsigned long __init free_all_bootmem(void)
 {
 #ifdef CONFIG_NO_BOOTMEM
-	return free_all_memory_core_early(NODE_DATA(0)->node_id);
+	/*
+	 * We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id
+	 *  because in some case like Node0 doesnt have RAM installed
+	 *  low ram will be on Node1
+	 * Use MAX_NUMNODES will make sure all ranges in early_node_map[]
+	 *  will be used instead of only Node0 related
+	 */
+	return free_all_memory_core_early(MAX_NUMNODES);
 #else
-	return free_all_bootmem_core(NODE_DATA(0)->bdata);
+	unsigned long total_pages = 0;
+	bootmem_data_t *bdata;
+
+	list_for_each_entry(bdata, &bdata_list, list)
+		total_pages = free_all_bootmem_core(bdata);
+
+	return total_pages;
 #endif
 }