Re: [PATCH v5 1/6] xen/x86: Provide helpers for common code to access acpi_numa

From: Jan Beulich <jbeulich@suse.com>
To: Wei Chen <wei.chen@arm.com>
Cc: nd@arm.com, "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH v5 1/6] xen/x86: Provide helpers for common code to access acpi_numa
Date: Tue, 27 Sep 2022 09:37:15 +0200	[thread overview]
Message-ID: <5547335f-9e01-d461-f866-c0f823aa2814@suse.com> (raw)
In-Reply-To: <20220920091218.1208658-2-wei.chen@arm.com>

On 20.09.2022 11:12, Wei Chen wrote:
> --- a/xen/arch/x86/numa.c
> +++ b/xen/arch/x86/numa.c
> @@ -50,9 +50,28 @@ nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
>  bool numa_off;
>  s8 acpi_numa = 0;
>  
> -int srat_disabled(void)
> +int __init arch_numa_setup(const char *opt)
>  {
> -    return numa_off || acpi_numa < 0;
> +#ifdef CONFIG_ACPI_NUMA
> +    if ( !strncmp(opt, "noacpi", 6) )
> +    {
> +        numa_off = false;
> +        acpi_numa = -1;

When making the v5 changes, did you go over the results to check they are
actually consistent? I'm afraid they still aren't, because of the line
above: Here we disable NUMA, but that doesn't mean there's broken firmware.
Therefore I guess I need to ask for another round of renaming of the two
helper functions; I'm sorry for that. What you introduce ...

> +        return 0;
> +    }
> +#endif
> +
> +    return -EINVAL;
> +}
> +
> +bool arch_numa_broken(void)
> +{
> +    return acpi_numa < 0;
> +}

... here wants to be arch_numa_disabled(), whereas the function currently
named this way (in patch 5) wants to be e.g. arch_numa_unavailable() (or,
using inverted sense, arch_numa_available()). Of course I'll be happy to
see other naming suggestions for both functions, as long as they reflect
the respective purposes.

Alternatively, to retain the current naming, the assignments to acpi_numa
would need revising. But I think that would be the more fragile approach.

Jan