According to Intel x2apic spec page 46 " The hand-off to OSPM will have processor IDs in the range of 0 to 254 for xAPIC/x2APIC and 0 to 255 for SAPIC declared as either Processor() or Device() objects, but not both. Processor IDs outside these ranges must be declared as Device() objects." So only check if Device is used when acpi_id >=255. that will help system with less 255 cpus, but some cpus apic id > 255, still can use Processor statement instead of Device() objects. Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> --- drivers/acpi/processor_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/drivers/acpi/processor_core.c =================================================================== --- linux-2.6.orig/drivers/acpi/processor_core.c +++ linux-2.6/drivers/acpi/processor_core.c @@ -69,7 +69,7 @@ static int map_x2apic_id(struct acpi_sub if (!(apic->lapic_flags & ACPI_MADT_ENABLED)) return 0; - if (device_declaration && (apic->uid == acpi_id)) { + if ((device_declaration || (acpi_id < 255)) && (apic->uid == acpi_id)) { *apic_id = apic->local_apic_id; return 1; } -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html