[PATCH] x86_64: Make node boundaries consistent

The current x86_64 NUMA memory code is inconsequent when it comes to node
memory ranges. The exact behaviour varies depending on which config option
that is used.

setup_node_bootmem() has start and end as arguments and these are used to
calculate the size of the node like this: (end - start). This is all fine
if end is pointing to the first non-available byte. The problem is that the
current x86_64 code sometimes treats it as the last present byte and sometimes
as the first non-available byte. The result is that some configurations might
lose a page at the end of the range.

This patch tries to fix CONFIG_ACPI_NUMA, CONFIG_K8_NUMA and CONFIG_NUMA_EMU
so they all treat the end variable as the first non-available byte. This is
the same way as the single node code.

The patch is boot tested on dual x86_64 hardware with the above configurations,
but maybe the removed code is needed as some workaround?

Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 1 insertions, 6 deletions

diff --git a/arch/x86_64/mm/k8topology.c b/arch/x86_64/mm/k8topology.c
index 65417b0..a5663e0b 100644
--- a/arch/x86_64/mm/k8topology.c
+++ b/arch/x86_64/mm/k8topology.c
@@ -108,6 +108,7 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end)
 		limit >>= 16; 
 		limit <<= 24; 
 		limit |= (1<<24)-1;
+		limit++;
 
 		if (limit > end_pfn << PAGE_SHIFT)
 			limit = end_pfn << PAGE_SHIFT;
diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index edd5559..629ff06 100644
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -209,8 +209,6 @@ static int numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
  		if (i == numa_fake-1)
  			sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start;
  		nodes[i].end = nodes[i].start + sz;
- 		if (i != numa_fake-1)
- 			nodes[i].end--;
  		printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
  		       i,
  		       nodes[i].start, nodes[i].end,
diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index c7aa08a..33340bd 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -71,8 +71,6 @@ static __init void cutoff_node(int i, unsigned long start, unsigned long end)
 			nd->start = nd->end;
 	}
 	if (nd->end > end) {
-		if (!(end & 0xfff))
-			end--;
 		nd->end = end;
 		if (nd->start > nd->end)
 			nd->start = nd->end;
@@ -166,8 +164,6 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 		if (nd->end < end)
 			nd->end = end;
 	}
-	if (!(nd->end & 0xfff))
-		nd->end--;
 	printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
 	       nd->start, nd->end);
 }