RE: [PATCH 14/37] xen/x86: use name fw_numa to replace acpi_numa

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Jan,

> -----Original Message-----
> From: Jan Beulich <jbeulich@xxxxxxxx>
> Sent: 2022年1月25日 18:13
> To: Wei Chen <Wei.Chen@xxxxxxx>
> Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>; xen-
> devel@xxxxxxxxxxxxxxxxxxxx; sstabellini@xxxxxxxxxx; julien@xxxxxxx
> Subject: Re: [PATCH 14/37] xen/x86: use name fw_numa to replace acpi_numa
> 
> On 23.09.2021 14:02, Wei Chen wrote:
> > --- a/xen/arch/x86/numa.c
> > +++ b/xen/arch/x86/numa.c
> > @@ -51,11 +51,11 @@ cpumask_t node_to_cpumask[MAX_NUMNODES]
> __read_mostly;
> >  nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
> >
> >  bool numa_off;
> > -s8 acpi_numa = 0;
> > +s8 fw_numa = 0;
> 
> In x86 code I'd prefer this to remain "acpi_numa". If you need to access
> the variable from to-become-generic code, introduce an inline wrapper
> (possibly named numa_mode()), allowing you to do whatever you need in the
> DT case. It may be helpful to fold this with numa_off then, seeing e.g.
> ...
> 
> >  int srat_disabled(void)
> >  {
> > -    return numa_off || acpi_numa < 0;
> > +    return numa_off || fw_numa < 0;
> 
> ... this. Actually I think the underlying enumeration could even be made
> generic:
> 
> enum numa_mode {
>     numa_off,
>     numa_on,
>     numa_acpi,
> };
> 
> is, I believe, sufficient to express the present (numa_off,acpi_numa)
> tuple. In this context I'd like to point out that the two uses of
> acpi_numa in srat_parse_regions() and srat_detect_node() should likely
> be invocations of srat_disabled() instead, to also take numa_off into
> account. This would then be addressed effectively as a side effect by
> replacing open-coded uses as well as srat_disabled() by numa_mode() (or
> whichever name the new helper would gain).
> 

Yes, that seems more reasonable, I will try this in next version.

> Jan