Re: [PATCH] asm, x86: Set max CPUs to 512 instead of 256.

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 22/01/15 16:52, Konrad Rzeszutek Wilk wrote:
> Contemporary servers sport now 480 CPUs or such. We should crank
> up the default amount of CPUs to a higher level to take advantage
> of this without having the distro to use 'max_phys_cpus' override.
>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

/me would really like to try something that big out, but I have not had
the opportunity yet to hit the 256 limit.

I wonder which variables grow as a result of this change.  We might want
to see about making more things dynamically allocated after reading the
apci tables, if we can.

~Andrew

> ---
>  xen/include/asm-x86/config.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
> index 2fbd68d..d450696 100644
> --- a/xen/include/asm-x86/config.h
> +++ b/xen/include/asm-x86/config.h
> @@ -64,7 +64,7 @@
>  #ifdef MAX_PHYS_CPUS
>  #define NR_CPUS MAX_PHYS_CPUS
>  #else
> -#define NR_CPUS 256
> +#define NR_CPUS 512
>  #endif
>  
>  /* Linkage for x86 */