Re: [PATCH v3 0/7] sched: Flatten the pick

[K Prateek Nayak <kprateek.nayak@amd.com>]

Hello Szabina,

On 8/17/2026 9:35 PM, Szabina Korbai wrote:
> Hello Peter,
> 
> We ran the same benchmarks (schbench, sysbench, hackbench) as Shubhang
> has on s390 on an LPAR running fedora 43 with 32 vCPUs.
> 
> We ran the benchmarks for each of the cgroup modes, and for the
> baseline, we chose the commit prior to the patches (f666241e6bd5 -
> sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime() ).
> 
> We have also tried running stress-ng in parallel with the benchmarks
> (set to generate 50% or 90% utilization for each vCPU).
> 
> Compared to simply running the benchmarks on their own, this has
> revealed some performance trade-offs that the move to a single runqueue
> can introduce.

Are you using tip:sched/core at commit 68e3748781 ("sched/fair: Fix flat
hierarchy") for the flat_cg numbers or did you checkout at 85570f10a4c6
("sched/eevdf: Move to a single runqueue")?

There are a couple fixes for vruntime update and Vincent's optimizations
for preemption bits which might make a difference to the overall
results.

-- 
Thanks and Regards,
Prateek