From 29380be579f156c1ebf06a6f98ecb8ed797290aa Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@suse.de>
Date: Fri, 3 Feb 2006 21:51:17 +0100
Subject: [PATCH] --- yaml --- r: 19773 b: refs/heads/master c:
 9391a3f9c7f17bdd82adf9a98905450642cc8970 h: refs/heads/master i:   19771:
 8de75f75b53bf92f59da0b5197dba22bb92ac713 v: v3

---
 [refs]                      |  2 +-
 trunk/arch/x86_64/mm/srat.c | 26 ++++++++++++++++++++------
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index d8531e590132..6fb7b8232bdf 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 00ac59adfca8f2f339beb0b67054e786c275553e
+refs/heads/master: 9391a3f9c7f17bdd82adf9a98905450642cc8970
diff --git a/trunk/arch/x86_64/mm/srat.c b/trunk/arch/x86_64/mm/srat.c
index 8b7f85608fa8..3bd827f5611f 100644
--- a/trunk/arch/x86_64/mm/srat.c
+++ b/trunk/arch/x86_64/mm/srat.c
@@ -26,6 +26,10 @@ static nodemask_t nodes_found __initdata;
 static struct node nodes[MAX_NUMNODES] __initdata;
 static u8 pxm2node[256] = { [0 ... 255] = 0xff };
 
+/* Too small nodes confuse the VM badly. Usually they result
+   from BIOS bugs. */
+#define NODE_MIN_SIZE (4*1024*1024)
+
 static int node_to_pxm(int n);
 
 int pxm_to_node(int pxm)
@@ -223,6 +227,16 @@ static int nodes_cover_memory(void)
 	return 1;
 }
 
+static void unparse_node(int node)
+{
+	int i;
+	node_clear(node, nodes_parsed);
+	for (i = 0; i < MAX_LOCAL_APIC; i++) {
+		if (apicid_to_node[i] == node)
+			apicid_to_node[i] = NUMA_NO_NODE;
+	}
+}
+
 void __init acpi_numa_arch_fixup(void) {}
 
 /* Use the information discovered above to actually set up the nodes. */
@@ -230,16 +244,16 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end)
 {
 	int i;
 
-	if (acpi_numa <= 0)
-		return -1;
-
 	/* First clean up the node list */
-	for_each_node_mask(i, nodes_parsed) {
+	for (i = 0; i < MAX_NUMNODES; i++) {
 		cutoff_node(i, start, end);
-		if (nodes[i].start == nodes[i].end)
-			node_clear(i, nodes_parsed);
+		if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE)
+			unparse_node(i);
 	}
 
+	if (acpi_numa <= 0)
+		return -1;
+
 	if (!nodes_cover_memory()) {
 		bad_srat();
 		return -1;