x86: enable NMI watchdog on nosmp

if nosmp has been passed as a boot option, but nmi_watchdog=2 has also
been enabled then keep minimal local APIC functionality around to make
the watchdog work.

this allowed me to debug a hard hang that would only occur with a nosmp
bootup.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar 2007-10-17 18:04:34 +02:00 committed by Thomas Gleixner
parent 2f62c94176
commit 3fb450a327

View file

@ -1021,6 +1021,12 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
if (!max_cpus) {
smp_found_config = 0;
printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
if (nmi_watchdog == NMI_LOCAL_APIC) {
printk(KERN_INFO "activating minimal APIC for NMI watchdog use.\n");
connect_bsp_APIC();
setup_local_APIC();
}
smpboot_clear_io_apic_irqs();
phys_cpu_present_map = physid_mask_of_physid(0);
cpu_set(0, per_cpu(cpu_sibling_map, 0));