This patch set is to allow kdump 2nd kernel to wake up multiple CPUs even if 1st kernel crashs on some AP. Sorry, this patch set have not include in-source documentation requested by Borislav Petkov yet, but I'll post it later separately, which would be better to focus on documentation reviewing. ChangeLog v2 => v3) - Change default value of boot_cpu_is_bsp to true. - Before executing rdmsr(MSR_IA32_APICBASE), check if the number of processor family is larger than or equal to 6 in order to avoid invalid opcode exception on processors where MSR_IA32_APICBASE is not supported. v1 => v2) - Rebased on top of v3.12-rc5. - Fix linking time error of boot_cpu_is_bsp_init() in case of CONFIG_LOCAL_APIC disabled by adding empty static inline function instead. - Fix missing feature check by means of cpu_has_apic macro in boot_cpu_is_bsp_init() before calling rdmsr_safe(MSR_IA32_APICBASE). NOTE: I've checked local apic-present case only; I don't have any x86 processor without local apic. - Add __init annotation to boot_cpu_is_bsp_init(). Test - built with and without CONFIG_LOCAL_APIC - tested x86_64 in case of acpi and MP table --- HATAYAMA Daisuke (2): x86, apic: Add boot_cpu_is_bsp() to check if boot cpu is BSP x86, apic: Disable BSP if boot cpu is AP arch/x86/include/asm/mpspec.h | 9 ++++++++- arch/x86/kernel/acpi/boot.c | 6 +++++- arch/x86/kernel/apic/apic.c | 35 ++++++++++++++++++++++++++++++++++- arch/x86/kernel/devicetree.c | 1 + arch/x86/kernel/mpparse.c | 15 +++++++++++++-- arch/x86/kernel/setup.c | 2 ++ arch/x86/platform/sfi/sfi.c | 2 +- 7 files changed, 64 insertions(+), 6 deletions(-) -- Thanks. HATAYAMA, Daisuke