Re: [xfs] bad77c375e: stress-ng.fallocate.ops_per_sec -10.0% regression

[Xing Zhengjun]

Hi Dave,

   Do you have time to look at this? Thanks.

On 9/2/2021 3:27 PM, kernel test robot wrote:
> Greeting,
>
> FYI, we noticed a -10.0% regression of stress-ng.fallocate.ops_per_sec due to commit:
>
>
> commit: bad77c375e8de6c776c848e443f7dc2d0d909be5 ("xfs: CIL checkpoint flushes caches unconditionally")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>
>
> in testcase: stress-ng
> on test machine: 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 512G memory
> with following parameters:
>
> 	nr_threads: 10%
> 	disk: 1HDD
> 	testtime: 60s
> 	fs: xfs
> 	class: filesystem
> 	test: fallocate
> 	cpufreq_governor: performance
> 	ucode: 0x5003006
>
>
> In addition to that, the commit also has significant impact on the following tests:
>
>
>
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
>
>
> Details are as below:
> -------------------------------------------------------------------------------------------------->
>
>
> To reproduce:
>
>          git clone https://github.com/intel/lkp-tests.git
>          cd lkp-tests
>          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
>          bin/lkp run                    generated-yaml-file
>
> =========================================================================================
> class/compiler/cpufreq_governor/disk/fs/kconfig/nr_threads/rootfs/tbox_group/test/testcase/testtime/ucode:
>    filesystem/gcc-9/performance/1HDD/xfs/x86_64-rhel-8.3/10%/debian-10.4-x86_64-20200603.cgz/lkp-csl-2sp7/fallocate/stress-ng/60s/0x5003006
>
> commit:
>    0431d926b3 ("xfs: async blkdev cache flush")
>    bad77c375e ("xfs: CIL checkpoint flushes caches unconditionally")
>
> 0431d926b399d74f bad77c375e8de6c776c848e443f
> ---------------- ---------------------------
>           %stddev     %change         %stddev
>               \          |                \
>      618.67           -10.0%     556.67 ±  2%  stress-ng.fallocate.ops
>       10.31           -10.0%       9.28 ±  2%  stress-ng.fallocate.ops_per_sec
>      111618            -5.7%     105270        stress-ng.time.voluntary_context_switches
>      502.67 ±  2%     +52.0%     763.83 ± 47%  interrupts.CPU44.CAL:Function_call_interrupts
>        2.10 ±  2%     -25.1%       1.57        iostat.cpu.iowait
>        2.16 ±  2%      -0.5        1.62        mpstat.cpu.all.iowait%
>        0.09 ± 11%     +45.0%       0.14 ± 34%  perf-sched.sch_delay.avg.ms.worker_thread.kthread.ret_from_fork
>      151.00 ± 19%     +20.2%     181.50 ±  7%  perf-sched.wait_and_delay.count.smpboot_thread_fn.kthread.ret_from_fork
>        6749            +6.4%       7178        perf-stat.i.context-switches
>        6640            +6.4%       7063        perf-stat.ps.context-switches
>      353877            -1.4%     348924        proc-vmstat.pgfree
>       39122           -15.1%      33221        proc-vmstat.pgpgout
>        1225 ± 14%      -9.0%       1115        turbostat.Bzy_MHz
>       86.82 ± 17%     -10.4%      77.83        turbostat.PkgWatt
>      602.83           -15.1%     511.83        vmstat.io.bo
>        6953            +6.1%       7376        vmstat.system.cs
>        1.33 ±  6%      +0.4        1.70 ± 13%  perf-profile.calltrace.cycles-pp.perf_mux_hrtimer_handler.__hrtimer_run_queues.hrtimer_interrupt.__sysvec_apic_timer_interrupt.sysvec_apic_timer_interrupt
>        0.08 ± 22%      +0.1        0.17 ± 23%  perf-profile.children.cycles-pp.wait_for_completion
>        0.07 ± 17%      +0.1        0.19 ± 64%  perf-profile.children.cycles-pp.submit_bio
>        0.07 ± 17%      +0.1        0.19 ± 64%  perf-profile.children.cycles-pp.submit_bio_noacct
>        1.40 ±  8%      +0.3        1.74 ± 12%  perf-profile.children.cycles-pp.perf_mux_hrtimer_handler
>
>
>                                                                                  
>                           stress-ng.fallocate.ops_per_sec
>                                                                                  
>    12 +----------------------------------------------------------------------+
>       |                                                                      |
>    10 |.+.++.+.+.+  +.+.+.++.+.+.++.+.+.+.++.+.+.++.+.+.++.+.+.+.++.+.+.++.+.|
>       | O        :  :                             O O   OO O O O OO          |
>       |   OO O   :O :            O             O O    O                      |
>     8 |-+      O :  : O O OO O O  O O O O OO O                               |
>       |          : :                                                         |
>     6 |-+        : :                                                         |
>       |           ::                                                         |
>     4 |-+         ::                                                         |
>       |           ::                                                         |
>       |           ::                                                         |
>     2 |-+         :                                                          |
>       |           :                                                          |
>     0 +----------------------------------------------------------------------+
>                                                                                  
>                                                                                  
> [*] 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.
>
>
> ---
> 0DAY/LKP+ Test Infrastructure                   Open Source Technology Center
> https://lists.01.org/hyperkitty/list/lkp@xxxxxxxxxxxx       Intel Corporation
>
> Thanks,
> Oliver Sang

--
Zhengjun Xing