[PATCH -v3] x86, numa: Fix cross nodes memory configuration

From: Yinghai Lu
Date: Sun Oct 10 2010 - 22:54:11 EST



Russ reported SGI UV is broken recently. He said:

| The SRAT table shows that memory range is spread over two nodes.
|
| SRAT: Node 0 PXM 0 100000000-800000000
| SRAT: Node 1 PXM 1 800000000-1000000000
| SRAT: Node 0 PXM 0 1000000000-1080000000
|
|Previously, the kernel early_node_map[] would show three entries
|with the proper node.
|
|[ 0.000000] 0: 0x00100000 -> 0x00800000
|[ 0.000000] 1: 0x00800000 -> 0x01000000
|[ 0.000000] 0: 0x01000000 -> 0x01080000
|
|The problem is recent community kernel early_node_map[] shows
|only two entries with the node 0 entry overlapping the node 1
|entry.
|
| 0: 0x00100000 -> 0x01080000
| 1: 0x00800000 -> 0x01000000

After looking at the changelog, Found out that it has been broken for a while by
following commit

|commit 8716273caef7f55f39fe4fc6c69c5f9f197f41f1
|Author: David Rientjes <rientjes@xxxxxxxxxx>
|Date: Fri Sep 25 15:20:04 2009 -0700
|
| x86: Export srat physical topology

Before that commit, register_active_regions() is called for every SRAT memory
entry right away.

Try to use nodememblk_range[] instead of nodes[].

For stable tree: from 2.6.33 to 2.3.36 need this patch

-v3: update to linus's tree.

Reported-by: Russ Anderson <rja@xxxxxxx>
Tested-by: Russ Anderson <rja@xxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: stable@xxxxxxxxxx

---
arch/x86/mm/srat_64.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-2.6/arch/x86/mm/srat_64.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/srat_64.c
+++ linux-2.6/arch/x86/mm/srat_64.c
@@ -420,9 +420,11 @@ int __init acpi_scan_nodes(unsigned long
return -1;
}

- for_each_node_mask(i, nodes_parsed)
- e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
- nodes[i].end >> PAGE_SHIFT);
+ for (i = 0; i < num_node_memblks; i++)
+ e820_register_active_regions(memblk_nodeid[i],
+ node_memblk_range[i].start >> PAGE_SHIFT,
+ node_memblk_range[i].end >> PAGE_SHIFT);
+
/* for out of order entries in SRAT */
sort_node_map();
if (!nodes_cover_memory(nodes)) {
--
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