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

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


If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-lkp/[email protected]


Details are as below:
-------------------------------------------------------------------------------------------------->


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260611/[email protected]

=========================================================================================
compiler/cpufreq_governor/kconfig/nr_threads/rootfs/tbox_group/test/testcase/testtime:
  gcc-14/performance/x86_64-rhel-9.4/100%/debian-13-x86_64-20250902.cgz/lkp-emr-2sp1/kill/stress-ng/60s

commit: 
  a26d9208c1 ("Merge branch 'sched/cache'")
  9e005ed211 ("sched/topology: Allow multiple domains to claim sched_domain_shared")

a26d9208c1376ac3 9e005ed21152d4a4bb0ceea7104 
---------------- --------------------------- 
         %stddev     %change         %stddev
             \          |                \  
     16542            -5.6%      15623        stress-ng.kill.kill_calls_per_sec
  66940342            -4.6%   63830711        stress-ng.kill.ops
   1116630            -4.6%    1064849        stress-ng.kill.ops_per_sec
     50279            +5.7%      53164        meminfo.KernelStack
     14019 ± 46%     -48.8%       7174 ± 70%  numa-vmstat.node2.nr_slab_reclaimable
     10643 ± 21%     +49.0%      15853 ± 19%  numa-vmstat.node3.nr_slab_reclaimable
     50278            +5.7%      53144        proc-vmstat.nr_kernel_stack
     74611            +1.0%      75344        proc-vmstat.nr_vmalloc
    613641            +5.5%     647439 ±  3%  proc-vmstat.pgfree
     56078 ± 46%     -48.8%      28697 ± 70%  numa-meminfo.node2.KReclaimable
     56078 ± 46%     -48.8%      28697 ± 70%  numa-meminfo.node2.SReclaimable
     42574 ± 21%     +49.1%      63467 ± 19%  numa-meminfo.node3.KReclaimable
     42574 ± 21%     +49.1%      63467 ± 19%  numa-meminfo.node3.SReclaimable
      0.03 ± 55%     -64.7%       0.01 ± 99%  sched_debug.cfs_rq:/.spread.avg
      0.26 ± 27%     -55.0%       0.12 ± 84%  sched_debug.cfs_rq:/.spread.stddev
      4715 ± 14%     -28.3%       3380 ± 44%  sched_debug.cpu.curr->pid.min
      0.32 ±  3%      -8.3%       0.30 ±  3%  sched_debug.cpu.nr_running.stddev
     22.17 ± 31%    +128.9%      50.75 ± 12%  sched_debug.cpu.nr_uninterruptible.max
      3.99 ± 14%     +55.6%       6.20 ±  4%  sched_debug.cpu.nr_uninterruptible.stddev




Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.


-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki