* Aneesh Kumar K.V [off-list ref] [2023-11-15 11:24:59]:

Srikar Dronamraju [off-list ref] writes:

quoted

PowerVM systems configured in shared processors mode have some unique
challenges. Some device-tree properties will be missing on a shared
processor. Hence some sched domains may not make sense for shared processor
systems.

Most shared processor systems are over-provisioned. Underlying PowerVM
Hypervisor would schedule at a Big Core granularity. The most recent power
processors support two almost independent cores. In a lightly loaded
condition, it helps the overall system performance if we pack to lesser
number of Big Cores.

Is this good to do if the systems are not over-provisioned? What will be
the performance impact in that case with and without the change?

We are consolidating 1 thread per thread group (aka SMT domain).
Since each thread-group is suppose to be independent including having a
private L1/L2/L3 cache, we expect minimal impact in non over provisioned
scenario.

In Over utilization scenario, the changes in this patchset will not even kick in.

-- 
Thanks and Regards
Srikar Dronamraju