Re: [PATCH v3 2/7] sched/topology: Define and assign sched_domain flag metadata

[Quentin Perret]

Hey Valentin,

On Wednesday 01 Jul 2020 at 20:06:50 (+0100), Valentin Schneider wrote:
> +/*
> + * Domain members have different CPU capacities
> + *
> + * SHARED_PARENT: Set from the topmost domain down to the first domain where
> + * asymmetry is detected.
> + */
> +SD_FLAG(SD_ASYM_CPUCAPACITY,    5, SDF_SHARED_PARENT)

Probably not a huge deal, but I don't think this is _exactly_ how
SD_ASYM_CPUCAPACITY was defined originally, nor how the topology
detection code deals with it (IIRC).

That is, IIRC Morten defined SD_ASYM_CPUCAPACITY as the _lowest_ domain
at which all CPU capacities are visible. On all real systems I can think
of, this domain also happens to be the topmost domain, so that might not
be a huge deal and we can probably change that definition to the one you
suggest. But we should perhaps make the matching changes to
asym_cpu_capacity_level()/build_sched_domains() if we're going down that
path?

Thanks,
Quentin