Re: [PATCH 0/4] powerpc/topology: Introduce llc_override debugfs

["Chen, Yu C" <yu.c.chen@intel.com>]

On 10/13/2026 5:15 AM, Tim Chen wrote:
> On Mon, 2026-10-12 at 15:50 +0530, Shrikanth Hegde wrote:

[ ... ]

>>
>> Tim, Chenyu, Peter,
>> Are there any selftest or patches which is used for
>> functional validation of cache aware scheduling?
> 
> We haven't created one. We validate mostly with workloads such as
> hackbench, schbench and yogini (which can vary the number of threads
> over time and track CPU assignment). I agree they are not ideal for
> functional checks of the load balance path.
> 
>> per-LLC occupancy in /proc/{PID}/schedstat may not tell the full
>> story when there are multiple processes and multiple LLC's.
>>
>> Atleast for functional verification, we might need one if there is
>> not one already. The reason being,
>> - At present, we may need a custom workload. hackbench/schbench are
>>    wakeup intensive and typically bail out even before load balance.
>> - stress-ng is per process. So doesn't get cache aware scheduling.
>> - A selftest could spwan specific number of threads till llc size etc
>>    and ensure packing happens till core_count(llc_size) by default.
>>    This could also be used for tunable verfifications.
>> - Provide an ability to observe how much of the workload was contained
>>    within the LLC due to cache aware scheduling or number of load
>>    balances stopped due to preferred llc.
> 
> A selftest would be great and much welcomed.
> 

Yes, that would be very useful. For functional testing, previously we
asked AI to generate a trial test script to launch a random number of
while(1) tests and watch their occupancy on each LLC.

thanks,
Chenyu