Re: [PATCH] x86: allow 8 more cpus could be used

[Randy Dunlap <randy.dunlap@oracle.com>]

Ingo Molnar wrote:
> * Randy Dunlap <randy.dunlap@oracle.com> wrote:
> 
>> Ingo Molnar wrote:
>>> * Yinghai Lu <yinghai@kernel.org> wrote:
>>>
>>>> Impact: fix left out MARCO
>>>>
>>>> X86_PC will be always enabled. so need to check if we have bigsmp 
>>>> support built in before cut off more than 8 cpus.
>>> ah, that's a leftover reference to X86_PC. It can now be removed, together 
>>> with the Kconfig X86_PC option.
>>>
>>>> -#if defined(CONFIG_X86_PC) && defined(CONFIG_X86_32)
>>>> +#if defined(CONFIG_X86_PC) && !defined(CONFIG_X86_BIGSMP)
>>>>  	if (def_to_bigsmp && nr_cpu_ids > 8) {
>>>>  		unsigned int cpu;
>>>>  		unsigned nr;
>>> Could you please send a patch that removes both X86_PC and X86_BIGSMP - 
>>> and removes the above cutoff code too, so that it will be built-in all the 
>>> time?
>> and at what cost, please?
> 
> the size difference between a bigsmp and a normal-smp x86 defconfig kernel 
> is 0.011%. Zero difference on a UP kernel. (And UP is what most of the 
> ultra-embedded systems are using)

That's static size?  how about cpu and apic table space?


Thanks,
-- 
~Randy