On AMD EPYC 7252 Hardware configs: AMD64 32 CPUs 128G RAM, numa nodes: 2 Software configs: OS: ubuntu 20.04 Official kernel: 5.15 hwe (5.15.0-86.96~20.04.1) Test kernel: 5.15 hwe (5.15.0-86.96~20.04.1+test20231013b0) https://launchpad.net/~gerald-yang-tw/+archive/ubuntu/focal-no-hz-full Test case 1, without NO_HZ_FULL built-in (default ubuntu kernel config): Run test program 4 times without taskset tail -n 2 log/notaskset.* ==> log/notaskset.1 <== total 14800791827 nsec avg 148 nsec ==> log/notaskset.2 <== total 14800224701 nsec avg 148 nsec ==> log/notaskset.3 <== total 14995047523 nsec avg 149 nsec ==> log/notaskset.4 <== total 15056157604 nsec avg 150 nsec Run test program 4 times with taskset to CPU 4 tail -n 2 log/taskset.* ==> log/taskset.1 <== total 14886363654 nsec avg 148 nsec ==> log/taskset.2 <== total 14954637921 nsec avg 149 nsec ==> log/taskset.3 <== total 14784359811 nsec avg 147 nsec ==> log/taskset.4 <== total 14971006444 nsec avg 149 nsec Test case 2, with NO_HZ_FULL built-in but not activate in kernel cmdline: Run test program 4 times without taskset tail -n 2 nohz-log/notaskset.* ==> nohz-log1/notaskset.1 <== total 15481330071 nsec avg 154 nsec ==> nohz-log1/notaskset.2 <== total 15336097628 nsec avg 153 nsec ==> nohz-log1/notaskset.3 <== total 15465283005 nsec avg 154 nsec ==> nohz-log1/notaskset.4 <== total 15575165790 nsec avg 155 nsec Run test program 4 times with taskset to CPU 4 tail -n 2 nohz-log1/taskset.* ==> nohz-log1/taskset.1 <== total 15492308210 nsec avg 154 nsec ==> nohz-log1/taskset.2 <== total 15481404702 nsec avg 154 nsec ==> nohz-log1/taskset.3 <== total 15386525422 nsec avg 153 nsec ==> nohz-log1/taskset.4 <== total 15393744615 nsec avg 153 nsec