Re: [LKP] [lkp] [rcu] b8084f70e0: No primary result change, 1414.7% unixbench.time.involuntary_context_switches

From: Huang\, Ying
Date: Tue Jan 05 2016 - 23:26:05 EST


"Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> writes:

> On Wed, Jan 06, 2016 at 10:47:43AM +0800, kernel test robot wrote:
>> FYI, we noticed the below changes on
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git for-kbuild-bot/current-stable
>> commit b8084f70e028697b342d6388b244d6171717fc54 ("rcu: Eliminate softirq processing from rcutree")
>
> This is a performance degradation, correct? If so, looks like this commit
> is not ready for mainline unless set up to be configured on only for
> -rt workloads.

Yes. This is a performance degradation.

> Or am I missing the plot somewhere here?

Which plot?

Best Regards,
Huang, Ying

> Thanx, Paul
>
>> =========================================================================================
>> compiler/cpufreq_governor/kconfig/nr_task/rootfs/tbox_group/test/testcase:
>> gcc-4.9/performance/x86_64-rhel/1/debian-x86_64-2015-02-07.cgz/lkp-ivb-d02/fsbuffer/unixbench
>>
>> commit:
>> ee644236a506642e20637f954d286f49a76ed83a
>> b8084f70e028697b342d6388b244d6171717fc54
>>
>> ee644236a506642e b8084f70e028697b342d6388b2
>> ---------------- --------------------------
>> %stddev %change %stddev
>> \ | \
>> 257.25 18% +1414.7% 3896 13% unixbench.time.involuntary_context_switches
>> 4425148 22% -61.9% 1684712 29% cpuidle.C1E-IVB.time
>> 83.75 48% +91.6% 160.50 31% cpuidle.POLL.usage
>> 1902 7% -12.0% 1674 1% slabinfo.anon_vma.active_objs
>> 1902 7% -12.0% 1674 1% slabinfo.anon_vma.num_objs
>> 257.25 18% +1414.7% 3896 13% time.involuntary_context_switches
>> 8.15 6% -14.1% 7.00 1% time.user_time
>> 34345 14% -33.3% 22908 33% sched_debug.cfs_rq:/.exec_clock.2
>> 34987 13% -19.7% 28093 15% sched_debug.cfs_rq:/.exec_clock.max
>> 642.75 5% +59.6% 1025 55% sched_debug.cfs_rq:/.exec_clock.min
>> 14639 13% -21.8% 11443 16% sched_debug.cfs_rq:/.exec_clock.stddev
>> 127.75 16% -26.2% 94.25 25% sched_debug.cfs_rq:/.load_avg.3
>> 38865 12% -36.0% 24885 34% sched_debug.cfs_rq:/.min_vruntime.2
>> 39385 12% -22.8% 30395 16% sched_debug.cfs_rq:/.min_vruntime.max
>> 1090 11% +45.3% 1584 32% sched_debug.cfs_rq:/.min_vruntime.min
>> 16286 13% -25.1% 12200 18% sched_debug.cfs_rq:/.min_vruntime.stddev
>> 2.00 0% -50.0% 1.00 0% sched_debug.cfs_rq:/.nr_spread_over.0
>> 2.00 0% -50.0% 1.00 0% sched_debug.cfs_rq:/.nr_spread_over.max
>> 0.87 0% -42.3% 0.50 0% sched_debug.cfs_rq:/.nr_spread_over.stddev
>> 28.50 62% +338.6% 125.00 114% sched_debug.cfs_rq:/.runnable_load_avg.1
>> 16286 13% -25.1% 12200 18% sched_debug.cfs_rq:/.spread0.stddev
>> 127.75 16% -26.0% 94.50 25% sched_debug.cfs_rq:/.tg_load_avg_contrib.3
>> 626662 5% -13.2% 544121 9% sched_debug.cpu.avg_idle.0
>> 20.25 28% +419.8% 105.25 132% sched_debug.cpu.cpu_load[3].1
>> 692.40 7% -15.2% 586.96 9% sched_debug.cpu.curr->pid.avg
>> 36187 12% -31.5% 24793 29% sched_debug.cpu.nr_load_updates.2
>> 15625 11% +61.6% 25245 23% sched_debug.cpu.nr_switches.0
>> 20008 4% +14.1% 22828 4% sched_debug.cpu.nr_switches.avg
>> 23333 8% +40.9% 32872 18% sched_debug.cpu.sched_count.0
>> 21974 4% +12.7% 24771 4% sched_debug.cpu.sched_count.avg
>> 31771 9% +22.6% 38942 5% sched_debug.cpu.sched_count.max
>> 9514 28% +75.8% 16728 7% sched_debug.cpu.ttwu_count.0
>> 4323 10% +40.6% 6080 30% sched_debug.cpu.ttwu_count.2
>> 10068 4% +15.6% 11639 4% sched_debug.cpu.ttwu_count.avg
>> 4101 10% +21.7% 4990 8% sched_debug.cpu.ttwu_count.min
>> 3676 21% +102.5% 7443 8% sched_debug.cpu.ttwu_local.0
>> 2014 15% +43.2% 2884 10% sched_debug.cpu.ttwu_local.2
>> 3508 1% +24.8% 4377 4% sched_debug.cpu.ttwu_local.avg
>> 5554 19% +34.0% 7444 8% sched_debug.cpu.ttwu_local.max
>> 1846 16% +40.2% 2588 6% sched_debug.cpu.ttwu_local.min
>>
>> =========================================================================================
>> compiler/cpufreq_governor/kconfig/nr_task/rootfs/tbox_group/test/testcase:
>> gcc-4.9/performance/x86_64-rhel/1/debian-x86_64-2015-02-07.cgz/lkp-ivb-d02/fsdisk/unixbench
>>
>> commit:
>> ee644236a506642e20637f954d286f49a76ed83a
>> b8084f70e028697b342d6388b244d6171717fc54
>>
>> ee644236a506642e b8084f70e028697b342d6388b2
>> ---------------- --------------------------
>> fail:runs %reproduction fail:runs
>> | | |
>> :4 25% 1:4 kmsg.DHCP/BOOTP:Reply_not_for_us,op[#]xid[#]
>> %stddev %change %stddev
>> \ | \
>> 265.75 18% +1313.4% 3756 9% unixbench.time.involuntary_context_switches
>> 659.50 6% +16.5% 768.00 7% slabinfo.kmalloc-512.num_objs
>> 265.75 18% +1313.4% 3756 9% time.involuntary_context_switches
>> 5911312 13% -55.9% 2606719 10% cpuidle.C1E-IVB.time
>> 95195 172% +815.7% 871684 140% cpuidle.POLL.time
>> 51.75 10% -30.9% 35.75 24% cpuidle.POLL.usage
>> 13361 22% -27.0% 9754 4% sched_debug.cfs_rq:/.exec_clock.stddev
>> 14632 24% -28.1% 10524 5% sched_debug.cfs_rq:/.min_vruntime.stddev
>> 14632 24% -28.1% 10524 5% sched_debug.cfs_rq:/.spread0.stddev
>> 197.25 14% +52.9% 301.50 41% sched_debug.cfs_rq:/.util_avg.0
>> 552666 8% -7.7% 510200 7% sched_debug.cpu.avg_idle.1
>> 13610 30% +59.7% 21734 7% sched_debug.cpu.nr_switches.0
>> 21145 1% +12.3% 23752 7% sched_debug.cpu.nr_switches.avg
>> 10105 21% +62.1% 16380 7% sched_debug.cpu.nr_switches.min
>> 11293 28% -44.4% 6276 16% sched_debug.cpu.nr_switches.stddev
>> 21314 19% +38.1% 29437 5% sched_debug.cpu.sched_count.0
>> 11261 22% +57.2% 17703 9% sched_debug.cpu.sched_count.min
>> 11158 27% -36.7% 7068 12% sched_debug.cpu.sched_count.stddev
>> 5854 35% +57.0% 9194 8% sched_debug.cpu.sched_goidle.0
>> 3713 27% +68.4% 6253 11% sched_debug.cpu.sched_goidle.min
>> 5638 29% -44.5% 3131 18% sched_debug.cpu.sched_goidle.stddev
>> 8286 32% +85.0% 15333 15% sched_debug.cpu.ttwu_count.0
>> 10697 1% +13.2% 12107 7% sched_debug.cpu.ttwu_count.avg
>> 4845 5% +17.8% 5707 8% sched_debug.cpu.ttwu_count.min
>> 2886 47% +105.5% 5931 16% sched_debug.cpu.ttwu_local.0
>> 3667 3% +17.0% 4291 1% sched_debug.cpu.ttwu_local.avg
>> 2127 17% +29.2% 2748 7% sched_debug.cpu.ttwu_local.min
>>
>>
>> lkp-ivb-d02: Ivy Bridge
>> Memory: 8G
>>
>> unixbench.time.involuntary_context_switches
>>
>> 5000 ++-------------------------------------------------------------------+
>> 4500 O+ |
>> | O O O O O
>> 4000 ++ O O O |
>> 3500 ++O O O O O O O O O O O |
>> | O O O |
>> 3000 ++ O O |
>> 2500 ++ |
>> 2000 ++ |
>> | |
>> 1500 ++ |
>> 1000 ++ |
>> |.*.. .*.. .*. .*.*.. .*.. |
>> 500 *+ * *.*..*.*. *. .*.. .*.*..* *.*..*.* |
>> 0 ++----------O---------O-------*----*------O----O---------------------+
>>
>> [*] bisect-good sample
>> [O] bisect-bad sample
>>
>> To reproduce:
>>
>> git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
>> cd lkp-tests
>> bin/lkp install job.yaml # job file is attached in this email
>> bin/lkp run job.yaml
>>
>>
>> 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
>
>> ---
>> LKP_SERVER: inn
>> LKP_CGI_PORT: 80
>> LKP_CIFS_PORT: 139
>> testcase: unixbench
>> default-monitors:
>> wait: activate-monitor
>> kmsg:
>> uptime:
>> iostat:
>> vmstat:
>> numa-numastat:
>> numa-vmstat:
>> numa-meminfo:
>> proc-vmstat:
>> proc-stat:
>> interval: 10
>> meminfo:
>> slabinfo:
>> interrupts:
>> lock_stat:
>> latency_stats:
>> softirqs:
>> bdi_dev_mapping:
>> diskstats:
>> nfsstat:
>> cpuidle:
>> cpufreq-stats:
>> turbostat:
>> pmeter:
>> sched_debug:
>> interval: 60
>> cpufreq_governor: performance
>> default-watchdogs:
>> oom-killer:
>> watchdog:
>> commit: b8084f70e028697b342d6388b244d6171717fc54
>> model: Ivy Bridge
>> nr_cpu: 4
>> memory: 8G
>> nr_hdd_partitions: 1
>> hdd_partitions: "/dev/disk/by-id/ata-ST1000DM003-1CH162_Z1DBQSB0-part1"
>> swap_partitions: "/dev/disk/by-id/ata-ST1000DM003-1CH162_Z1DBQSB0-part3"
>> rootfs_partition: "/dev/disk/by-id/ata-ST1000DM003-1CH162_Z1DBQSB0-part4"
>> netconsole_port: 66723
>> category: benchmark
>> nr_task: 1
>> unixbench:
>> test: fsdisk
>> queue: bisect
>> testbox: lkp-ivb-d02
>> tbox_group: lkp-ivb-d02
>> kconfig: x86_64-rhel
>> enqueue_time: 2016-01-05 16:24:11.468660360 +08:00
>> id: 62c43434378ef50b95fcd4973759daf66a148734
>> user: lkp
>> compiler: gcc-4.9
>> head_commit: 5bae791e5bb8895ac3d65634231c99d79a0e0002
>> base_commit: 168309855a7d1e16db751e9c647119fe2d2dc878
>> branch: linux-devel/devel-hourly-2016010502
>> rootfs: debian-x86_64-2015-02-07.cgz
>> result_root: "/result/unixbench/performance-1-fsdisk/lkp-ivb-d02/debian-x86_64-2015-02-07.cgz/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/0"
>> job_file: "/lkp/scheduled/lkp-ivb-d02/bisect_unixbench-performance-1-fsdisk-debian-x86_64-2015-02-07.cgz-x86_64-rhel-b8084f70e028697b342d6388b244d6171717fc54-20160105-89027-193oala-0.yaml"
>> max_uptime: 922.0999999999999
>> initrd: "/osimage/debian/debian-x86_64-2015-02-07.cgz"
>> bootloader_append:
>> - root=/dev/ram0
>> - user=lkp
>> - job=/lkp/scheduled/lkp-ivb-d02/bisect_unixbench-performance-1-fsdisk-debian-x86_64-2015-02-07.cgz-x86_64-rhel-b8084f70e028697b342d6388b244d6171717fc54-20160105-89027-193oala-0.yaml
>> - ARCH=x86_64
>> - kconfig=x86_64-rhel
>> - branch=linux-devel/devel-hourly-2016010502
>> - commit=b8084f70e028697b342d6388b244d6171717fc54
>> - BOOT_IMAGE=/pkg/linux/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/vmlinuz-4.4.0-rc6-00236-gb8084f7
>> - max_uptime=922
>> - RESULT_ROOT=/result/unixbench/performance-1-fsdisk/lkp-ivb-d02/debian-x86_64-2015-02-07.cgz/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/0
>> - LKP_SERVER=inn
>> - |2-
>>
>>
>> earlyprintk=ttyS0,115200 systemd.log_level=err
>> debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100
>> panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0
>> console=ttyS0,115200 console=tty0 vga=normal
>>
>> rw
>> lkp_initrd: "/lkp/lkp/lkp-x86_64.cgz"
>> modules_initrd: "/pkg/linux/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/modules.cgz"
>> bm_initrd: "/osimage/deps/debian-x86_64-2015-02-07.cgz/lkp.cgz,/osimage/deps/debian-x86_64-2015-02-07.cgz/run-ipconfig.cgz,/osimage/deps/debian-x86_64-2015-02-07.cgz/turbostat.cgz,/lkp/benchmarks/turbostat.cgz,/lkp/benchmarks/unixbench.cgz"
>> linux_headers_initrd: "/pkg/linux/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/linux-headers.cgz"
>> repeat_to: 2
>> kernel: "/pkg/linux/x86_64-rhel/gcc-4.9/b8084f70e028697b342d6388b244d6171717fc54/vmlinuz-4.4.0-rc6-00236-gb8084f7"
>> dequeue_time: 2016-01-05 16:39:47.706440461 +08:00
>> job_state: finished
>> loadavg: 0.58 0.25 0.10 1/123 2689
>> start_time: '1451983209'
>> end_time: '1451983353'
>> version: "/lkp/lkp/.src-20160105-162125"
>
>
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