Re: [PATCH] ACPI: boot correctly with "nosmp" or "maxcpus=0"

[Andi Kleen <ak@suse.de>]

> @@ -157,10 +162,13 @@ early_param("nosmp", nosmp);
>  static int __init maxcpus(char *str)
>  {
>  	get_option(&str, &max_cpus);
> -	return 1;
> +	if (max_cpus == 0)
> +		disable_ioapic_setup();

I must say I never liked that maxcpus=0 ... does disable the APIC
too. There can be situations where you want only a single CPU,
but still full APICs because modern systems don't boot without. 

It's the old traditional documented semantics though,
but on the other hand if it never worked with ACPI i guess people are
not relying on it.

So perhaps it would be better to change that? 
Or add a new option to limit CPUs without disabling ACPIC?

-Andi