Re: [RFC][PATCH v021 0/9] cpufreq: intel_pstate: Enable EAS on hybrid platforms without SMT

[Dietmar Eggemann <dietmar.eggemann@arm.com>]

On 29/11/2024 16:55, Rafael J. Wysocki wrote:

[...]

> For easier access, the series is available on the experimental/intel_ostate
> branch in linux-pm.git:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=experimental/intel_pstate

I was wondering how we can test the EAS behaviour (power/perf) on Intel
hybrid machines.

I have system-wide RAPL 'power/energy-{cores,pkg}' events for power
(energy) on my i7-13700K (nosmt) so I can run an rt-app workload
(e.g. 30 5% tasks (0.8ms/16ms)) with:

perf stat -e power/energy-cores/,power/energy-pkg/ --repeat 10 ./rt-app.sh

Plus I can check for negative slack for those rt-app-test tasks (perf)
and do ftrace-based task placement evaluation.

base:

 Performance counter stats for 'system wide' (10 runs):

       52.67 Joules power/energy-cores/       ( +-  1.24% )
       85.09 Joules power/energy-pkg/         ( +-  0.83% )

   34.922801 +- 0.000736 seconds time elapsed ( +-  0.00% )


EAS:

 Performance counter stats for 'system wide' (10 runs):

       45.55 Joules power/energy-cores/       ( +-  1.07% )
       75.73 Joules power/energy-pkg/         ( +-  0.67% )

   34.93183 +- 0.00514 seconds time elapsed  ( +-  0.01% )

Do you have another (maybe more sophisticated) test methodology?