[anolis-intel-cloud:devel-5.10] [sched/fair] e213519c64: netperf.Throughput_tps 3.8% regression

[anolis-intel-cloud:devel-5.10] [sched/fair] e213519c64: netperf.Throughput_tps 3.8% regression

[kernel test robot]

Hello,

kernel test robot noticed a 3.8% regression of netperf.Throughput_tps on:

commit: e213519c64ec899502f211079bb2a4603cb8ab53 ("sched/fair: Avoid a second scan of target in select_idle_cpu") https://gitee.com/anolis/intel-cloud-kernel.git devel-5.10

testcase: netperf
config: x86_64-anolis-intel-cloud-devel-5.10
compiler: gcc-14
test machine: 256 threads 2 sockets Intel(R) Xeon(R) 6768P  CPU @ 2.4GHz (Granite Rapids) with 64G memory
parameters:

	ip: ipv4
	runtime: 300s
	nr_threads: 200%
	cluster: cs-localhost
	test: TCP_RR
	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 <yi1.lai@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202610091252.d0d6cae8-lkp@intel.com


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


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20261009/202610091252.d0d6cae8-lkp@intel.com

=========================================================================================
cluster/compiler/cpufreq_governor/ip/kconfig/nr_threads/rootfs/runtime/tbox_group/test/testcase:
  cs-localhost/gcc-14/performance/ipv4/x86_64-anolis-intel-cloud-devel-5.10/200%/debian-13-x86_64-20250902.cgz/300s/lkp-gnr-2sp4/TCP_RR/netperf

commit: 
  eb34bf470a ("sched/fair: Bring back select_idle_smt(), but differently")
  e213519c64 ("sched/fair: Avoid a second scan of target in select_idle_cpu")

eb34bf470aa84e3d e213519c64ec899502f211079bb
---------------- --------------------------- 
         %stddev     %change         %stddev
             \          |                \  
  28413404            -3.8%   27329713 ±  2%  netperf.ThroughputBoth_total_tps
     55494            -3.8%      53378 ±  2%  netperf.ThroughputBoth_tps
  28413404            -3.8%   27329713 ±  2%  netperf.Throughput_total_tps
     55494            -3.8%      53378 ±  2%  netperf.Throughput_tps
      1932 ±  2%      -5.1%       1833        netperf.time.user_time
 8.524e+09            -3.8%  8.199e+09 ±  2%  netperf.workload


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