Re: [PATCH 1/5] numa: avoid export acpi_numa variable

[David Rientjes <rientjes@google.com>]

On Mon, 4 Feb 2013, liguang wrote:

> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
> index 0c44630..c4e0875 100644
> --- a/arch/x86/include/asm/acpi.h
> +++ b/arch/x86/include/asm/acpi.h
> @@ -181,7 +181,8 @@ static inline void disable_acpi(void) { }
>  #define ARCH_HAS_POWER_INIT	1
>  
>  #ifdef CONFIG_ACPI_NUMA
> -extern int acpi_numa;
> +extern void bad_srat(void);
> +extern bool srat_disabled(void);

So anything that wants to disable acpi_numa, such as xen, must call a 
function named bad_srat()?  That seems a little misnamed itself.

>  extern int x86_acpi_numa_init(void);
>  #endif /* CONFIG_ACPI_NUMA */
>  
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 2d125be..92986d8 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -47,7 +47,7 @@ static __init int numa_setup(char *opt)
>  #endif
>  #ifdef CONFIG_ACPI_NUMA
>  	if (!strncmp(opt, "noacpi", 6))
> -		acpi_numa = -1;
> +		bad_srat();

This will print an error line saying "SRAT: SRAT not used." which wasn't 
emitted before.  I don't think that's the desire.

>  #endif
>  	return 0;
>  }
> diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
> index 4ddf497..a837c95 100644
> --- a/arch/x86/mm/srat.c
> +++ b/arch/x86/mm/srat.c
> @@ -24,22 +24,22 @@
>  #include <asm/apic.h>
>  #include <asm/uv/uv.h>
>  
> -int acpi_numa __initdata;
> +static bool acpi_numa __initdata;
>  

You've changed this to be type bool but didn't update the existing code 
that still does "acpi_numa = 1".

>  static __init int setup_node(int pxm)
>  {
>  	return acpi_map_pxm_to_node(pxm);
>  }
>  
> -static __init void bad_srat(void)
> +void __init bad_srat(void)
>  {
>  	printk(KERN_ERR "SRAT: SRAT not used.\n");
> -	acpi_numa = -1;
> +	acpi_numa = false;
>  }
>  
> -static __init inline int srat_disabled(void)
> +bool __init srat_disabled(void)
>  {
> -	return acpi_numa < 0;
> +	return acpi_numa;
>  }
>  
>  /* Callback for SLIT parsing */
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 138e566..94c8c70 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1415,7 +1415,7 @@ asmlinkage void __init xen_start_kernel(void)
>  	 * any NUMA information the kernel tries to get from ACPI will
>  	 * be meaningless.  Prevent it from trying.
>  	 */
> -	acpi_numa = -1;
> +	bad_srat();

Same as before.  It seems like you want to introduce a new function 
specifically to disable it:

	void acpi_numa_disable(void)
	{
		acpi_numa = false;
	}

and then bad_srat() should call into it?