linux-kernel - Re: [Patch v3 1/2] x86/mm/numa: Open code function early_get_boot_cpu

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Message-ID: <20160810140148.GA22965@gmail.com>
Date:	Wed, 10 Aug 2016 16:01:48 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Baoquan He <bhe@...hat.com>
Cc:	rjw@...ysocki.net, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [Patch v3 1/2] x86/mm/numa: Open code function
 early_get_boot_cpu_id


* Baoquan He <bhe@...hat.com> wrote:

> Previously early_acpi_boot_init is called in early_get_boot_cpu_id()
> to get value for boot_cpu_physical_apicid. Now early_acpi_boot_init()
> has been taken out and moved to setup_arch(), the name of
> early_get_boot_cpu_id doesn't match its implementation. And only the
> getting boot-time SMP configuration code is left. So in this patch
> open code it.
> 
> Signed-off-by: Baoquan He <bhe@...hat.com>
> ---
> v1->v3:
>   No change from v1.
> 
>  arch/x86/mm/amdtopology.c | 25 ++++++++-----------------
>  1 file changed, 8 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/x86/mm/amdtopology.c b/arch/x86/mm/amdtopology.c
> index 2ca15b59..9928dad 100644
> --- a/arch/x86/mm/amdtopology.c
> +++ b/arch/x86/mm/amdtopology.c
> @@ -53,21 +53,6 @@ static __init int find_northbridge(void)
>  	return -ENOENT;
>  }
>  
> -static __init void early_get_boot_cpu_id(void)
> -{
> -	/*
> -	 * need to get the APIC ID of the BSP so can use that to
> -	 * create apicid_to_node in amd_scan_nodes()
> -	 */
> -#ifdef CONFIG_X86_MPPARSE
> -	/*
> -	 * get boot-time SMP configuration:
> -	 */
> -	if (smp_found_config)
> -		early_get_smp_config();
> -#endif
> -}
> -
>  int __init amd_numa_init(void)
>  {
>  	u64 start = PFN_PHYS(0);
> @@ -181,8 +166,14 @@ int __init amd_numa_init(void)
>  	cores = 1 << bits;
>  	apicid_base = 0;
>  
> -	/* get the APIC ID of the BSP early for systems with apicid lifting */
> -	early_get_boot_cpu_id();
> +#ifdef CONFIG_X86_MPPARSE
> +	/*
> +	 * get boot-time SMP configuration:
> +	 */
> +	if (smp_found_config)
> +		early_get_smp_config();
> +#endif

So I think this cleanup could be improved: any reason why the smp_found_config 
check is not done in early_get_smp_config()?

Plus it appears there's already a !CONFIG_X86_MPPARSE version of 
early_get_smp_config() [but please double check that it's available under all 
legitimate Kconfig variants] so we could drop the ugly #ifdef as well.

Thanks,

	Ingo