Subject: Re: [PATCH 2/3] powerpc/numa: Early request for home node associativity

From: Nathan Lynch <[email-masked]>
Date: Thu, 22 Aug 2019 13:33:13 -0500

Srikar Dronamraju <[email-masked]> writes:
> * Nathan Lynch <[email-masked]> [2019-08-22 12:17:48]:
>> > However home node associativity requires cpu's hwid which is set in
>> > smp_setup_pacas. Hence call smp_setup_pacas before numa_setup_cpus.
>> 
>> But this seems like it would negatively affect pacas' NUMA placements?
>> 
>> Would it be less risky to figure out a way to do "early" VPHN hcalls
>> before mem_topology_setup, getting the hwids from the cpu_to_phys_id
>> array perhaps?
>> 
>
> Do you mean for calls from mem_topology_setup(), stuff we use cpu_to_phys_id
> but for the calls from ppc_numa_cpu_prepare() we use the
> get_hard_smp_processor_id()?

Yes, something like that, I think. Although numa_setup_cpu() is used in
both contexts.