Greeting, FYI, we noticed a -14.4% regression of hackbench.throughput due to commit: commit: 4c77b18cf8b7ab37c7d5737b4609010d2ceec5f0 ("sched/fair: Make select_idle_cpu() more aggressive") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: hackbench on test machine: 48 threads 2 sockets Intel(R) Xeon(R) CPU E5-2697 v2 @ 2.70GHz with 64G memory with following parameters: nr_threads: 50% mode: process ipc: pipe cpufreq_governor: performance test-description: Hackbench is both a benchmark and a stress test for the Linux kernel scheduler. test-url: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/sched/cfs-scheduler/hackbench.c In addition to that, the commit also has significant impact on the following tests: +------------------+-----------------------------------------------------------------------+ | testcase: change | netperf: netperf.Throughput_tps -33.8% regression | | test machine | 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory | | test parameters | cluster=cs-localhost | | | cpufreq_governor=performance | | | ip=ipv4 | | | nr_threads=200% | | | runtime=300s | | | test=SCTP_RR | +------------------+-----------------------------------------------------------------------+ | testcase: change | netperf: netperf.Throughput_tps -50.8% regression | | test machine | 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory | | test parameters | cluster=cs-localhost | | | cpufreq_governor=performance | | | ip=ipv4 | | | nr_threads=200% | | | runtime=300s | | | test=TCP_RR | +------------------+-----------------------------------------------------------------------+ | testcase: change | netperf: netperf.Throughput_Mbps -8.7% regression | | test machine | 16 threads Intel(R) Xeon(R) CPU D-1541 @ 2.10GHz with 8G memory | | test parameters | cluster=cs-localhost | | | cpufreq_governor=performance | | | ip=ipv4 | | | nr_threads=200% | | | runtime=300s | | | send_size=10K | | | test=SCTP_STREAM_MANY | +------------------+-----------------------------------------------------------------------+ | testcase: change | hackbench: hackbench.throughput 12.1% improvement | | test machine | 8 threads Ivy Bridge with 16G memory | | test parameters | cpufreq_governor=performance | | | ipc=pipe | | | mode=process | | | nr_threads=50% | +------------------+-----------------------------------------------------------------------+ | testcase: change | netperf: netperf.Throughput_Mbps -2.5% regression | | test machine | 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory | | test parameters | cluster=cs-localhost | | | cpufreq_governor=performance | | | ip=ipv4 | | | nr_threads=200% | | | runtime=300s | | | send_size=10K | | | test=SCTP_STREAM_MANY | +------------------+-----------------------------------------------------------------------+ Details are as below: --------------------------------------------------------------------------------------------------> To reproduce: git clone https://github.com/01org/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml testcase/path_params/tbox_group/run: hackbench/50%-process-pipe-performance/ivb42 4977ab6e92e267af 4c77b18cf8b7ab37c7d5737b46 ---------------- -------------------------- 179106 -14% 153395 hackbench.throughput 5.036e+08 21% 6.113e+08 hackbench.time.involuntary_context_switches 4523 3% 4675 hackbench.time.percent_of_cpu_this_job_got 27089 3% 27956 hackbench.time.system_time 1394 -10% 1252 hackbench.time.user_time 2.501e+09 -11% 2.223e+09 hackbench.time.voluntary_context_switches 779669 -14% 667478 hackbench.time.minor_page_faults 319399 3% 329894 interrupts.CAL:Function_call_interrupts 884938 -22% 692644 vmstat.system.in 5224554 -9% 4736985 vmstat.system.cs 2880 2955 turbostat.Avg_MHz 96.25 98.77 turbostat.%Busy 6.59 -14% 5.63 turbostat.RAMWatt 2.009e+08 98% 3.986e+08 perf-stat.cpu-migrations 0.67 8% 0.73 perf-stat.branch-miss-rate% 5.046e+11 13% 5.722e+11 perf-stat.cache-references 5.897e+10 5% 6.22e+10 perf-stat.branch-misses 3851 16% 4471 perf-stat.instructions-per-iTLB-miss 38.80 -11% 34.53 perf-stat.node-store-miss-rate% 8.697e+13 8.833e+13 perf-stat.cpu-cycles 1928944 -8% 1777815 perf-stat.page-faults 1928944 -8% 1777789 perf-stat.minor-faults 1.332e+10 ± 3% -18% 1.098e+10 ± 16% perf-stat.dTLB-store-misses 1.87 ± 4% -20% 1.50 ± 19% perf-stat.dTLB-load-miss-rate% 2.654e+11 ± 4% -25% 1.988e+11 ± 20% perf-stat.dTLB-load-misses 0.53 -6% 0.50 perf-stat.ipc 8.738e+12 8.565e+12 perf-stat.branch-instructions 3.299e+09 -10% 2.968e+09 perf-stat.context-switches 4.586e+13 -4% 4.398e+13 perf-stat.instructions 64.05 31% 84.13 perf-stat.iTLB-load-miss-rate% 1.392e+13 -6% 1.306e+13 perf-stat.dTLB-loads 8.613e+12 -10% 7.773e+12 perf-stat.dTLB-stores 1.135e+10 ± 4% -45% 6.254e+09 ± 4% perf-stat.node-loads 1.878e+10 ± 3% -46% 1.016e+10 ± 4% perf-stat.cache-misses 1.1e+10 ± 4% -46% 5.949e+09 ± 4% perf-stat.node-load-misses 1.191e+10 -17% 9.836e+09 perf-stat.iTLB-load-misses 7.431e+09 ± 4% -48% 3.875e+09 ± 4% perf-stat.node-stores 3.72 ± 4% -52% 1.78 ± 4% perf-stat.cache-miss-rate% 4.711e+09 ± 4% -57% 2.044e+09 ± 3% perf-stat.node-store-misses 6.682e+09 -72% 1.856e+09 ± 3% perf-stat.iTLB-loads 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. Thanks, Ying Huang