Re: [PATCH v2 1/2] sched/topology: Allow archs to override cpu_smt_mask
From: Michael Ellerman
Date: Thu Sep 17 2020 - 07:34:38 EST
On Fri, 7 Aug 2020 13:15:16 +0530, Srikar Dronamraju wrote:
> cpu_smt_mask tracks topology_sibling_cpumask. This would be good for
> most architectures. One of the users of cpu_smt_mask(), would be to
> identify idle-cores. On Power9, a pair of SMT4 cores can be presented by
> the firmware as a SMT8 core for backward compatibility reasons.
> Powerpc allows LPARs to be live migrated from Power8 to Power9. Do note
> Power8 had only SMT8 cores. Existing software which has been
> developed/configured for Power8 would expect to see SMT8 core.
> Maintaining the illusion of SMT8 core is a requirement to make that
Applied to powerpc/next.
[1/2] sched/topology: Allow archs to override cpu_smt_mask
[2/2] powerpc/topology: Override cpu_smt_mask