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authorJonathan Corbet <corbet@lwn.net>2008-07-14 15:29:34 -0600
committerJonathan Corbet <corbet@lwn.net>2008-07-14 15:29:34 -0600
commit2fceef397f9880b212a74c418290ce69e7ac00eb (patch)
treed9cc09ab992825ef7fede4a688103503e3caf655 /drivers/acpi/numa.c
parentfeae1ef116ed381625d3731c5ae4f4ebcb3fa302 (diff)
parentbce7f793daec3e65ec5c5705d2457b81fe7b5725 (diff)
Merge commit 'v2.6.26' into bkl-removal
Diffstat (limited to 'drivers/acpi/numa.c')
-rw-r--r--drivers/acpi/numa.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 5d59cb33b1a..658e5f3abae 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -140,19 +140,42 @@ acpi_table_print_srat_entry(struct acpi_subtable_header *header)
}
}
+/*
+ * A lot of BIOS fill in 10 (= no distance) everywhere. This messes
+ * up the NUMA heuristics which wants the local node to have a smaller
+ * distance than the others.
+ * Do some quick checks here and only use the SLIT if it passes.
+ */
+static __init int slit_valid(struct acpi_table_slit *slit)
+{
+ int i, j;
+ int d = slit->locality_count;
+ for (i = 0; i < d; i++) {
+ for (j = 0; j < d; j++) {
+ u8 val = slit->entry[d*i + j];
+ if (i == j) {
+ if (val != LOCAL_DISTANCE)
+ return 0;
+ } else if (val <= LOCAL_DISTANCE)
+ return 0;
+ }
+ }
+ return 1;
+}
+
static int __init acpi_parse_slit(struct acpi_table_header *table)
{
struct acpi_table_slit *slit;
- u32 localities;
if (!table)
return -EINVAL;
slit = (struct acpi_table_slit *)table;
- /* downcast just for %llu vs %lu for i386/ia64 */
- localities = (u32) slit->locality_count;
-
+ if (!slit_valid(slit)) {
+ printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
+ return -EINVAL;
+ }
acpi_numa_slit_init(slit);
return 0;