diff options
Diffstat (limited to 'drivers/acpi/numa.c')
| -rw-r--r-- | drivers/acpi/numa.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c index 5d59cb33b1a5..658e5f3abae0 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; |