Hi, list As per the documentation( https://www.mjmwired.net/kernel/Documentation/nmi_watchdog.txt), which says: "In order to use the NMI watchdog, you need to have APIC support in your kernel. For SMP kernels, APIC support gets compiled in automatically. For UP, enable either CONFIG_X86_UP_APIC (Processor type and features -> Local APIC support on uniprocessors) or CONFIG_X86_UP_IOAPIC (Processor type and features -> IO-APIC support on uniprocessors) in your kernel config. For x86-64, the needed APIC is always compiled in." Can I draw the conclusion that the NMI watchdog is unavailable if manually disabling the related configurations for APIC(i.e. for x86-64 SMP kernels, the options are CONFIG_X86_LOCAL_APIC and CONFIG_X86_IO_APIC) ? Is it impossible to manually disable APIC for the kernel of the x86-64 platform? Thank you for your attention to this matter. Best regards.