Hello, kernel test robot noticed a 3.4% improvement of stress-ng.lockofd.ops_per_sec on: commit: 20f3337d350c4e1b4ac66d731fd4e98565bf6cc0 ("x86: don't use REP_GOOD or ERMS for small memory clearing") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master testcase: stress-ng test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory parameters: nr_threads: 10% disk: 1HDD testtime: 60s fs: ext4 class: os test: lockofd cpufreq_governor: performance Details are as below: --------------------------------------------------------------------------------------------------> To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests sudo bin/lkp install job.yaml # job file is attached in this email bin/lkp split-job --compatible job.yaml # generate the yaml file for lkp run sudo bin/lkp run generated-yaml-file # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. ========================================================================================= class/compiler/cpufreq_governor/disk/fs/kconfig/nr_threads/rootfs/tbox_group/test/testcase/testtime: os/gcc-12/performance/1HDD/ext4/x86_64-rhel-8.3/10%/debian-11.1-x86_64-20220510.cgz/lkp-icl-2sp7/lockofd/stress-ng/60s commit: 68674f94ff ("x86: don't use REP_GOOD or ERMS for small memory copies") 20f3337d35 ("x86: don't use REP_GOOD or ERMS for small memory clearing") 68674f94ffc9dddc 20f3337d350c4e1b4ac66d731fd ---------------- --------------------------- %stddev %change %stddev \ | \ 39.25 +2.2% 40.10 iostat.cpu.user 0.05 -0.0 0.03 ± 16% mpstat.cpu.all.soft% 1.212e+08 +3.4% 1.253e+08 stress-ng.lockofd.ops 2019682 +3.4% 2087883 stress-ng.lockofd.ops_per_sec 9.311e+08 +6.8% 9.944e+08 perf-stat.i.branch-instructions 0.67 -7.1% 0.63 perf-stat.i.cpi 1.172e+09 +2.5% 1.202e+09 perf-stat.i.dTLB-loads 0.00 ± 3% -0.0 0.00 ± 2% perf-stat.i.dTLB-store-miss-rate% 8.309e+08 +15.2% 9.575e+08 perf-stat.i.dTLB-stores 4.579e+09 +7.8% 4.934e+09 perf-stat.i.instructions 1.49 +7.8% 1.60 perf-stat.i.ipc 1.16 +62.7% 1.89 ± 2% perf-stat.i.metric.G/sec 1771 -28.8% 1261 ± 4% perf-stat.i.metric.M/sec 19.22 ± 2% -1.8 17.39 perf-profile.calltrace.cycles-pp.fcntl_setlk.do_fcntl.__x64_sys_fcntl.do_syscall_64.entry_SYSCALL_64_after_hwframe 53.24 -1.8 51.44 perf-profile.calltrace.cycles-pp.do_fcntl.__x64_sys_fcntl.do_syscall_64.entry_SYSCALL_64_after_hwframe 60.31 -1.5 58.83 perf-profile.calltrace.cycles-pp.__x64_sys_fcntl.do_syscall_64.entry_SYSCALL_64_after_hwframe 6.48 ± 4% -0.6 5.87 ± 4% perf-profile.calltrace.cycles-pp.kmem_cache_alloc.fcntl_setlk.do_fcntl.__x64_sys_fcntl.do_syscall_64 1.03 ± 7% -0.2 0.88 ± 10% perf-profile.calltrace.cycles-pp.flock64_to_posix_lock.fcntl_getlk.do_fcntl.__x64_sys_fcntl.do_syscall_64 5.76 ± 3% +0.4 6.12 ± 2% perf-profile.calltrace.cycles-pp.stress_mwc64modn 0.00 +1.5 1.51 ± 4% perf-profile.calltrace.cycles-pp.memset_orig.kmem_cache_alloc.fcntl_setlk.do_fcntl.__x64_sys_fcntl 0.00 +1.6 1.60 ± 7% perf-profile.calltrace.cycles-pp.memset_orig.kmem_cache_alloc.fcntl_getlk.do_fcntl.__x64_sys_fcntl 53.94 -1.7 52.24 perf-profile.children.cycles-pp.do_fcntl 19.65 -1.6 18.07 perf-profile.children.cycles-pp.fcntl_setlk 13.82 -1.0 12.83 ± 3% perf-profile.children.cycles-pp.kmem_cache_alloc 5.96 ± 3% +0.4 6.37 ± 3% perf-profile.children.cycles-pp.stress_mwc64modn 5.88 ± 2% +0.5 6.39 ± 3% perf-profile.children.cycles-pp.entry_SYSRETQ_unsafe_stack 0.00 +3.3 3.29 ± 5% perf-profile.children.cycles-pp.memset_orig 0.84 ± 9% +0.2 0.99 ± 9% perf-profile.self.cycles-pp.exit_to_user_mode_prepare 5.60 ± 2% +0.4 6.04 ± 3% perf-profile.self.cycles-pp.stress_mwc64modn 5.58 ± 2% +0.5 6.09 ± 2% perf-profile.self.cycles-pp.entry_SYSRETQ_unsafe_stack 0.00 +3.1 3.11 ± 5% perf-profile.self.cycles-pp.memset_orig 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