Re: [tip:sched/core] [sched/topology] 9e005ed211: stress-ng.kill.ops_per_sec 4.6% regression

[Chen, Yu C]

On 6/11/2026 10:19 AM, kernel test robot wrote:
> Hello,
>
> kernel test robot noticed a 4.6% regression of stress-ng.kill.ops_per_sec on:
>
>
> commit: 9e005ed21152d4a4bb0ceea71045ff8a642a6feb ("sched/topology: Allow multiple domains to claim sched_domain_shared")
> https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git sched/core
>
>
> testcase: stress-ng
> config: x86_64-rhel-9.4
> compiler: gcc-14
> test machine: 256 threads 4 sockets INTEL(R) XEON(R) PLATINUM 8592+ (Emerald Rapids) with 256G memory
> parameters:
>
> 	nr_threads: 100%
> 	testtime: 60s
> 	test: kill
> 	cpufreq_governor: performance

This 4.6% difference is very small and within normal run-to-run variance 
IMO, as
the commit has no functional changes.

BTW the commit log indicates nr_idle_scan is
initialized to a stale value 512, sds->alloc_flags = SD_SHARE_LLC, the 
wakeup
before the next period LB in this LLC domain might have slight higher 
latency though.
But consider your test last for 60 seconds which is much longer than the 
first period LB,
this should not be a problem.

thanks,
Chenyu