[PATCH] x86_64: Dont record local apic ids when they are disabled in MADT
Some broken BIOS's had processors disabled, but
same apic id as a valid processor. This causes
acpi_processor_start() to think this disabled
cpu is ok, and croak. So we dont record bad
apicid's anymore.
http://bugzilla.kernel.org/show_bug.cgi?id=5930
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index f21fa0d..79577f0 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -248,10 +248,17 @@
acpi_table_print_madt_entry(header);
- /* Register even disabled CPUs for cpu hotplug */
+ /* Record local apic id only when enabled */
+ if (processor->flags.enabled)
+ x86_acpiid_to_apicid[processor->acpi_id] = processor->id;
- x86_acpiid_to_apicid[processor->acpi_id] = processor->id;
-
+ /*
+ * We need to register disabled CPU as well to permit
+ * counting disabled CPUs. This allows us to size
+ * cpus_possible_map more accurately, to permit
+ * to not preallocating memory for all NR_CPUS
+ * when we use CPU hotplug.
+ */
mp_register_lapic(processor->id, /* APIC ID */
processor->flags.enabled); /* Enabled? */