Re: [lkp-robot] [sched/cfs] 625ed2bf04: unixbench.score -7.4% regression

From: Vincent Guittot
Date: Fri May 19 2017 - 03:09:21 EST

On 19 May 2017 at 08:07, kernel test robot <xiaolong.ye@xxxxxxxxx> wrote:
>
> Greeting,
>
> FYI, we noticed a -7.4% regression of unixbench.score due to commit:

That's interesting because it's just the opposite of what I received 4
days ago for unixbench shell1 test. I'm going to have a look:

>From kernel test robot <xiaolong.ye@xxxxxxxxx>:

Greeting,

FYI, we noticed a 12.3% improvement of unixbench.score due to commit:


commit: 6947ec09a6a15c9c2c2bf71d7fea7c65d54f8a33 ("sched/cfs: Make
util/load_avg more stable")
https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git schd/wip

in testcase: unixbench
on test machine: 192 threads Skylake-4S with 768G memory
with following parameters:

runtime: 300s
nr_task: 1
test: shell1
cpufreq_governor: performance

test-description: UnixBench is the original BYTE UNIX benchmark suite
aims to test performance of Unix-like system.
test-url: https://github.com/kdlucas/byte-unixbench

In addition to that, the commit also has significant impact on the
following tests:

+------------------+-----------------------------------------------------------------------+
| testcase: change | netperf: netperf.Throughput_tps 36.1% improvement
|
| test machine | 56 threads Intel(R) Xeon(R) CPU E5-2695 v3 @
2.30GHz with 256G memory |
| test parameters | cluster=cs-localhost
|
| | cpufreq_governor=performance
|
| | ip=ipv4
|
| | nr_threads=200%
|
| | runtime=300s
|
| | test=SCTP_RR
|
+------------------+-----------------------------------------------------------------------+
| testcase: change | aim9: aim9.shell_rtns_3.ops_per_sec 1.6%
improvement |
| test machine | 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @
2.20GHz with 64G memory |
| test parameters | cpufreq_governor=performance
|
| | test=shell_rtns_3
|
| | testtime=300s
|
+------------------+-----------------------------------------------------------------------+
| testcase: change | aim9: aim9.shell_rtns_1.ops_per_sec 1.4%
improvement |
| test machine | 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @
2.20GHz with 64G memory |
| test parameters | cpufreq_governor=performance
|
| | test=shell_rtns_1
|
| | testtime=300s
|
+------------------+-----------------------------------------------------------------------+

--




>
>
> commit: 625ed2bf049d5a352c1bcca962d6e133454eaaff ("sched/cfs: Make util/load_avg more stable")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>
> in testcase: unixbench
> on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 64G memory
> with following parameters:
>
> runtime: 300s
> nr_task: 100%
> test: spawn
> cpufreq_governor: performance
>
> test-description: UnixBench is the original BYTE UNIX benchmark suite aims to test performance of Unix-like system.
> test-url: https://github.com/kdlucas/byte-unixbench
>
>
>
> 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: unixbench/300s-100%-spawn-performance/lkp-bdw-ep3b
>
> 8663effb24f94303 625ed2bf049d5a352c1bcca962
> ---------------- --------------------------
> %stddev change %stddev
> \ | \
> 8888 -7% 8234 unixbench.score
> 11626 31% 15267 unixbench.time.system_time
> 5084 23% 6259 unixbench.time.percent_of_cpu_this_job_got
> 5203 5% 5455 unixbench.time.user_time
> 66039778 -7% 61588314 unixbench.time.voluntary_context_switches
> 7.932e+08 -7% 7.34e+08 unixbench.time.minor_page_faults
> 24502668 -52% 11794316 unixbench.time.involuntary_context_switches
> 628084 -17% 518637 interrupts.CAL:Function_call_interrupts
> 6000 Ä 57% 1e+04 19033 Ä 58% latency_stats.sum.call_rwsem_down_read_failed.__percpu_down_read.exit_signals.do_exit.do_group_exit.SyS_exit_group.entry_SYSCALL_64_fastpath
> 715117 Ä 58% -4e+05 300172 Ä 12% latency_stats.sum.io_schedule.__lock_page_or_retry.filemap_fault.__do_fault.__handle_mm_fault.handle_mm_fault.__do_page_fault.do_page_fault.page_fault
> 94622 96223 vmstat.system.in
> 500325 -16% 420024 vmstat.system.cs
> 1692 21% 2045 turbostat.Avg_MHz
> 60.71 21% 73.38 turbostat.%Busy
> 208 212 turbostat.PkgWatt
> 54.56 -8% 50.47 turbostat.RAMWatt
> 4.911e+13 21% 5.944e+13 perf-stat.cpu-cycles
> 6010 19% 7153 perf-stat.instructions-per-iTLB-miss
> 3.508e+12 14% 3.988e+12 perf-stat.branch-instructions
> 1.627e+13 10% 1.797e+13 perf-stat.instructions
> 4.504e+12 8% 4.886e+12 perf-stat.dTLB-loads
> 58.34 59.21 perf-stat.node-store-miss-rate%
> 42.85 42.00 perf-stat.iTLB-load-miss-rate%
> 3.609e+09 -4% 3.469e+09 perf-stat.iTLB-loads
> 2.125e+10 -5% 2.016e+10 perf-stat.branch-misses
> 2.707e+09 -7% 2.512e+09 perf-stat.iTLB-load-misses
> 7.939e+08 -7% 7.348e+08 perf-stat.page-faults
> 7.939e+08 -7% 7.348e+08 perf-stat.minor-faults
> 0.33 -9% 0.30 perf-stat.ipc
> 9.788e+09 -9% 8.927e+09 Ä 3% perf-stat.dTLB-load-misses
> 14.74 -9% 13.43 perf-stat.cache-miss-rate%
> 3.426e+11 -9% 3.117e+11 perf-stat.cache-references
> 1.26e+09 -9% 1.141e+09 perf-stat.dTLB-store-misses
> 1.579e+12 -10% 1.421e+12 perf-stat.dTLB-stores
> 1.773e+10 -14% 1.523e+10 perf-stat.node-load-misses
> 5.685e+09 -15% 4.805e+09 perf-stat.node-store-misses
> 0.22 -16% 0.18 Ä 3% perf-stat.dTLB-load-miss-rate%
> 1.666e+08 -16% 1.4e+08 perf-stat.context-switches
> 0.61 -17% 0.51 perf-stat.branch-miss-rate%
> 5.051e+10 -17% 4.187e+10 perf-stat.cache-misses
> 32471209 -18% 26608318 perf-stat.cpu-migrations
> 4.059e+09 -18% 3.311e+09 perf-stat.node-stores
> 8.13e+08 -24% 6.207e+08 perf-stat.node-loads
>
>
>
> unixbench.time.involuntary_context_switches
>
> 2.6e+07 ++----------------------------------------------------------------+
> *.*.*.. .*.*.*. .*.*.*. .*..*.*.*. .*..*.*.*.* |
> 2.4e+07 ++ * *..*.*. .*.*. * * |
> 2.2e+07 ++ * |
> | |
> 2e+07 ++ |
> O O O O |
> 1.8e+07 ++O |
> | |
> 1.6e+07 ++ |
> 1.4e+07 ++ |
> | |
> 1.2e+07 ++ O O O O O O O O O O O O |
> | O O O O O O O O O O O O O O
> 1e+07 ++----------------------------------------------------------------+
>
>
> perf-stat.cpu-cycles
>
> 6e+13 ++----------------------------------------------------------------+
> | O O O O O O O O O O O O O O O O O O O O O O O O O O
> 5.8e+13 ++ |
> | |
> | |
> 5.6e+13 O+O O O |
> | O |
> 5.4e+13 ++ |
> | |
> 5.2e+13 ++ |
> | |
> | |
> 5e+13 ++ .*. .*.*.*..*.*.*.*. .*. .*. .*. |
> *.*.*. * *..*.*.* *..*.*.* *..*.* * |
> 4.8e+13 ++----------------------------------------------------------------+
>
>
> perf-stat.node-load-misses
>
> 1.8e+10 ++---------------------------------------------------------------+
> *.*.*..*.*.*.* .*.*..*.*.*.*.*.*..*.*.*.*.*.* |
> 1.75e+10 ++ : * |
> 1.7e+10 ++ : .*. + |
> | *.*. *.* |
> 1.65e+10 ++ |
> | |
> 1.6e+10 ++ |
> | |
> 1.55e+10 O+ O O O O O O O
> 1.5e+10 ++ O O O O O O O O |
> | |
> 1.45e+10 ++O O O O O O O O O O O O O |
> | O |
> 1.4e+10 ++---------------O-----------------------------------------------+
>
>
> perf-stat.context-switches
>
> 1.7e+08 ++---------------------------------------------------------------+
> *.*.*.. .*.*.* .*.*..*. .*.*.*.*.. .*.*.*.*.* |
> 1.65e+08 ++ * + * * * |
> 1.6e+08 ++ *. .*. + |
> | *. *.* |
> 1.55e+08 ++ |
> | |
> 1.5e+08 ++ |
> | |
> 1.45e+08 O+O O O O |
> 1.4e+08 ++ O O O O O O O O |
> | O O O O O O
> 1.35e+08 ++ O O O O O O O O O O |
> | O O |
> 1.3e+08 ++---------------------------------------------------------------+
>
>
> perf-stat.cpu-migrations
>
> 3.3e+07 ++-----------------------------------------------------*-*--------+
> | .*..*. .*. * .*.*. .*.*. + |
> 3.2e+07 *+* * *. + + .*..*.* *..*.* *..*.* |
> 3.1e+07 ++ *..*.* * |
> | |
> 3e+07 ++ |
> | |
> 2.9e+07 ++ |
> | |
> 2.8e+07 ++ |
> 2.7e+07 ++ |
> O O O O O O O O O O O O O
> 2.6e+07 ++ O O O O O O |
> | O O O O O O O O O O O O |
> 2.5e+07 ++----------------------------------------------------------------+
>
>
> perf-stat.branch-miss-rate_
>
> 0.62 ++-------------------------------------------------------------------+
> *. .*. .*..*.*. *..*.*. .*. .*.*.. .*. .*.*.*.. .* |
> 0.6 ++*. * *.*.. + *. * * *. * |
> | *.* |
> 0.58 ++ |
> | |
> 0.56 ++ |
> | |
> 0.54 ++ |
> | |
> 0.52 ++ O O |
> O O O O O O |
> 0.5 ++ O O O O O O O O
> | O O O O O O O O O O |
> 0.48 ++O--O---O------O------O---------------------------------------------+
>
>
> perf-stat.ipc
>
> 0.335 ++------------------------------------------------------------------+
> *.*..*.*.*.*..* .*..*.*.*..*.*.*.*..*.*.*.*..*.* |
> 0.33 ++ : *.. * |
> 0.325 ++ : + + |
> | *.* *.* |
> 0.32 ++ |
> | |
> 0.315 ++ |
> | |
> 0.31 ++ |
> 0.305 ++ |
> O O O O O O O O O O O O O O
> 0.3 ++ O O O O O |
> | O O O O O O O O O O O O |
> 0.295 ++------------------------------------------------------------------+
>
>
> perf-stat.instructions-per-iTLB-miss
>
> 7400 ++-------------------------------------------------------------------+
> | O O O O O |
> 7200 ++O O O O O O O O O O O O O O O
> 7000 O+ O O O O O O O O O O |
> | |
> 6800 ++ |
> | |
> 6600 ++ |
> | |
> 6400 ++ |
> 6200 ++ *. .*. |
> *. + *..* *..*.*. .*.. |
> 6000 ++*..*. .*..*.* *..*. .* *.*. .*. .*..*.* |
> | * * *. * |
> 5800 ++-------------------------------------------------------------------+
>
>
> [*] bisect-good sample
> [O] bisect-bad sample
>
>
> 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,
> Xiaolong