[PATCH] x86_64: Clear more state when ignoring empty node in SRAT parsing

Might fix boot failures on systems with empty PXMs in SRAT

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index 8b7f856..3bd827f 100644 (file)
--- a/arch/x86_64/mm/srat.c
+++ b/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;