Re: [PATCH 1/2] x86/cpu/hygon: Introduce macros for hygon family numbers

[Ingo Molnar]

* Guo Chaohong <guochaohong@xxxxxxxxxxxxxx> wrote:

> hi, Ingo,
> 
> 
> Hygon model 7 CPUs have either 4 or 6 dies. All 6‑die variants share the
> same interconnect topology.
> The Hygon‑4G family includes several model numbers, not just model 7. The
> 3‑series CPUs are designed
> for desktop/workstation use and are only available in single‑socket systems.
> 
> The following is a summary of key Hygon models:
> 
> Model Name   Cores / Threads    Clock Speed   Target Segment           Model
> Number
> 7447V               96 / 192               ~2.6 GHz Enterprise / Cloud
> Server     7
> 7490H              96 / 192                —  High‑Density Server           
>  7 (now 7446)
> 7490                 64 / 128               2.7 GHz  Enterprise Serve       
>            4
> 7470                 48 / 96                  —  Enterprise Server         
>         4
> 
> Therefore, we will restrict this patch to apply only to model 7 CPUs that
> have 6 dies on a multi‑socket
> system and add sched domains topology after the change into commit message 
> in the V2 patch.

Understood - but my point is that the "HYGON_7447V" symbol name
is inaccurate:

	+#define        HYGON_F18_M07           HFM(0x18, 7)
	+
	+#define        HYGON_7447V             HYGON_F18_M07

Note how 'HYGON_7447V' also covers 7490H/7446.

IMHO it will be less confusing if you skip the HYGON_7447V interim
symbol and just use HYGON_F18_M07 in arch_sched_node_distance(),
and add a comment that clarifies that the additional conditions
basically filter for the 7447V variant.

Or if you want a clean 7447V enumeration function, add it as
an inline function and use that in arch_sched_node_distance().

Both approaches would be acceptable.

Thanks,

	Ingo