Re: [RFC PATCH RESEND 05/10] sched/fair: Introduce select_task_rq_fair_thin() to select rq when LB_PROMOTE

[Kayra Cizmeci]

Hello Xin,

> Testing has shown that in our system with 18 CPUs running at 2.1GHz, where
> the first three sd_llc domains each contains 4 CPUs and the last sd_llc
> contains 2 CPUs, under same fillback scenario, select_task_rq_fair_thin()
> executes 25% faster than the original select_task_rq_fair(). It saves 22ms
> over a 10-second period, with this optimization accounting for 0.174% of
> total system time. Additionally, we measured the execution time of
> update_idle_cpu_scan, which took 0.5ms over the same 10-second period. If
> we use select_task_rq_fair_thin() instead, this time can be eliminated,
> accounting for 0.04% of total system time. Therefore, the overall
> optimization contributes to a reduction of 0.214% of total system time.

Okay. Can you specify which tests you ran or what you used? If you can?

Thanks,
Kayra