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Message-ID: <CAP-5=fVTM3xV9feaZv4z53Pv-AM9Ldj7SC8rZcNsMwJcj2ZViQ@mail.gmail.com>
Date: Mon, 4 Sep 2023 07:54:05 -0700
From: Ian Rogers <irogers@...gle.com>
To: Yang Jihong <yangjihong1@...wei.com>
Cc: peterz@...radead.org, mingo@...hat.com, acme@...nel.org,
mark.rutland@....com, alexander.shishkin@...ux.intel.com,
jolsa@...nel.org, namhyung@...nel.org, adrian.hunter@...el.com,
kan.liang@...ux.intel.com, sandipan.das@....com,
ravi.bangoria@....com, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Subject: Re: [RFC v1 00/16] perf kwork: Implement perf kwork top
On Mon, Sep 4, 2023 at 4:59 AM Yang Jihong <yangjihong1@...wei.com> wrote:
>
> Hello,
>
> On 2023/9/4 13:13, Ian Rogers wrote:
> > On Sat, Aug 12, 2023 at 1:52 AM Yang Jihong <yangjihong1@...wei.com> wrote:
> >>
> >> Some common tools for collecting statistics on CPU usage, such as top,
> >> obtain statistics from timer interrupt sampling, and then periodically
> >> read statistics from /proc/stat.
> >>
> >> This method has some deviations:
> >> 1. In the tick interrupt, the time between the last tick and the current
> >> tick is counted in the current task. However, the task may be running
> >> only part of the time.
> >> 2. For each task, the top tool periodically reads the /proc/{PID}/status
> >> information. For tasks with a short life cycle, it may be missed.
> >>
> >> In conclusion, the top tool cannot accurately collect statistics on the
> >> CPU usage and running time of tasks.
> >>
> >> The statistical method based on sched_switch tracepoint can accurately
> >> calculate the CPU usage of all tasks. This method is applicable to
> >> scenarios where performance comparison data is of high precision.
> >>
> >> In addition to parsing the perf.data file, the provides BPF-based CPU usage
> >> statistics to reduce the load of the perf process.
> >>
> >> Example usage:
> >>
> >> # perf kwork top -h
> >>
> >> Usage: perf kwork top [<options>]
> >>
> >> -C, --cpu <cpu> list of cpus to profile
> >> -i, --input <file> input file name
> >> -n, --name <name> event name to profile
> >> -s, --sort <key[,key2...]>
> >> sort by key(s): rate, runtime, tid
> >> --time <str> Time span for analysis (start,stop)
> >>
> >> # ./perf kwork -k sched,irq,softirq record -- ./perf bench sched messaging -g 1 -l 10000
> >> # Running 'sched/messaging' benchmark:
> >> # 20 sender and receiver processes per group
> >> # 1 groups == 40 processes run
> >>
> >> Total time: 1.854 [sec]
> >> [ perf record: Woken up 13 times to write data ]
> >> [ perf record: Captured and wrote 27.436 MB perf.data (235986 samples) ]
> >> #
> >> # perf kwork top
> >>
> >> Total : 22419.068 ms, 12 cpus
> >> %Cpu(s): 17.99% id, 0.00% hi, 0.09% si
> >> %Cpu0 [|||||||||||||||||||||||| 82.56%]
> >> %Cpu1 [|||||||||||||||||||||||| 81.73%]
> >> %Cpu2 [|||||||||||||||||||||||| 83.00%]
> >> %Cpu3 [|||||||||||||||||||||||| 81.01%]
> >> %Cpu4 [|||||||||||||||||||||||| 81.66%]
> >> %Cpu5 [|||||||||||||||||||||||| 82.10%]
> >> %Cpu6 [|||||||||||||||||||||||| 81.65%]
> >> %Cpu7 [|||||||||||||||||||||||| 82.00%]
> >> %Cpu8 [|||||||||||||||||||||||| 82.54%]
> >> %Cpu9 [|||||||||||||||||||||||| 81.02%]
> >> %Cpu10 [|||||||||||||||||||||||| 81.78%]
> >> %Cpu11 [|||||||||||||||||||||||| 81.87%]
> >>
> >> PID %CPU RUNTIME COMMMAND
> >> ----------------------------------------------------
> >> 2913025 27.62 516.976 ms sched-messaging
> >> 2913017 27.56 516.273 ms sched-messaging
> >> 2913018 27.56 516.152 ms sched-messaging
> >> 2913008 27.54 515.447 ms sched-messaging
> >> 2913010 27.50 514.890 ms sched-messaging
> >> 2913007 27.48 514.411 ms sched-messaging
> >> 2913015 27.36 512.563 ms sched-messaging
> >> 2913026 27.35 512.198 ms sched-messaging
> >> 2913011 27.32 511.632 ms sched-messaging
> >> 2913014 27.32 511.381 ms sched-messaging
> >> 2913012 27.30 511.138 ms sched-messaging
> >> 2913013 27.30 511.109 ms sched-messaging
> >> 2913009 27.30 510.997 ms sched-messaging
> >> 2913019 27.25 510.488 ms sched-messaging
> >> 2913021 27.23 509.661 ms sched-messaging
> >> 2913023 27.21 509.400 ms sched-messaging
> >> 2913020 27.20 509.677 ms sched-messaging
> >> 2913022 27.19 509.061 ms sched-messaging
> >> 2913016 27.18 509.231 ms sched-messaging
> >> 2913024 27.18 509.108 ms sched-messaging
> >> 2912999 21.79 407.929 ms sched-messaging
> >> 2913000 21.78 408.045 ms sched-messaging
> >> 2912998 21.75 407.579 ms sched-messaging
> >> 2912993 21.69 406.166 ms sched-messaging
> >> 2912991 21.59 404.378 ms sched-messaging
> >> 2912992 21.57 403.845 ms sched-messaging
> >> 2913005 21.56 403.715 ms sched-messaging
> >> 2913001 21.55 403.803 ms sched-messaging
> >> 2912990 21.54 403.601 ms sched-messaging
> >> 2912994 21.52 403.087 ms sched-messaging
> >> 2912995 21.49 402.421 ms sched-messaging
> >> 2912996 21.48 402.666 ms sched-messaging
> >> 2912989 21.46 402.303 ms sched-messaging
> >> 2913003 21.46 402.034 ms sched-messaging
> >> 2912988 21.44 401.820 ms sched-messaging
> >> 2913004 21.37 400.242 ms sched-messaging
> >> 2912987 21.28 398.512 ms sched-messaging
> >> 2913002 21.27 398.759 ms sched-messaging
> >> 2912997 21.27 398.518 ms sched-messaging
> >> 2913006 21.23 397.888 ms sched-messaging
> >> 0 18.89 353.061 ms swapper/3
> >> 0 18.89 353.026 ms swapper/9
> >> 0 18.26 341.190 ms swapper/6
> >> 0 18.25 341.048 ms swapper/4
> >> 0 18.13 338.844 ms swapper/10
> >> 0 18.12 338.686 ms swapper/1
> >> 0 18.05 337.333 ms swapper/11
> >> 0 17.92 334.903 ms swapper/7
> >> 0 17.80 332.691 ms swapper/5
> >> 0 17.38 324.762 ms swapper/8
> >> 0 17.29 323.102 ms swapper/0
> >> 0 16.89 315.630 ms swapper/2
> >> 2912984 2.10 39.452 ms perf
> >> 2912985 0.73 14.004 ms sched-messaging
> >> 660381 0.14 3.527 ms containerd
> >> 3006112 0.07 1.402 ms redis-server
> >> 2904655 0.05 1.071 ms kworker/0:0
> >> 659822 0.03 1.729 ms containerd
> >> 659824 0.03 1.346 ms containerd
> >> 1053 0.01 0.353 ms zabbix_agentd
> >> 2895571 0.01 0.349 ms kworker/8:1
> >> 10 0.00 0.535 ms rcu_sched
> >> 2912192 0.00 0.272 ms kworker/u24:2
> >> 2903540 0.00 0.182 ms sshd
> >> 801 0.00 0.120 ms jbd2/sda4-8
> >> 2929605 0.00 0.108 ms grpc_global_tim
> >> 2912986 0.00 0.075 ms perf
> >> 2897765 0.00 0.073 ms kworker/7:1
> >> 2912817 0.00 0.070 ms kworker/2:1
> >> 391756 0.00 0.067 ms grpc_global_tim
> >> 2901459 0.00 0.056 ms kworker/3:0
> >> 2908185 0.00 0.052 ms kworker/10:1
> >> 2901521 0.00 0.050 ms kworker/6:1
> >> 2902444 0.00 0.046 ms kworker/5:1
> >> 2898513 0.00 0.041 ms kworker/1:1
> >> 2912280 0.00 0.039 ms kworker/11:3
> >> 1057 0.00 0.037 ms zabbix_agentd
> >> 2908010 0.00 0.037 ms kworker/9:3
> >> 2912951 0.00 0.036 ms kworker/4:3
> >> 793 0.00 0.027 ms multipathd
> >> 42 0.00 0.023 ms ksoftirqd/5
> >> 9 0.00 0.022 ms ksoftirqd/0
> >> 24 0.00 0.019 ms ksoftirqd/2
> >> 59 0.00 0.019 ms migration/8
> >> 2929607 0.00 0.018 ms wecode-db
> >> 29 0.00 0.012 ms migration/3
> >> 11 0.00 0.012 ms migration/0
> >> 65 0.00 0.012 ms migration/9
> >> 17 0.00 0.011 ms migration/1
> >> 71 0.00 0.011 ms migration/10
> >> 53 0.00 0.011 ms migration/7
> >> 23 0.00 0.011 ms migration/2
> >> 47 0.00 0.011 ms migration/6
> >> 789 0.00 0.010 ms multipathd
> >> 35 0.00 0.010 ms migration/4
> >> 480 0.00 0.009 ms kworker/4:1H
> >> 41 0.00 0.008 ms migration/5
> >> 54 0.00 0.006 ms ksoftirqd/7
> >> 36 0.00 0.005 ms ksoftirqd/4
> >> 72 0.00 0.005 ms ksoftirqd/10
> >> 66 0.00 0.005 ms ksoftirqd/9
> >> 30 0.00 0.004 ms ksoftirqd/3
> >> 2898362 0.00 0.003 ms kworker/u24:0
> >>
> >> # perf kwork top -C 2,4,5
> >>
> >> Total : 5604.885 ms, 3 cpus
> >> %Cpu(s): 17.65% id, 0.00% hi, 0.09% si
> >> %Cpu2 [|||||||||||||||||||||||| 83.00%]
> >> %Cpu4 [|||||||||||||||||||||||| 81.66%]
> >> %Cpu5 [|||||||||||||||||||||||| 82.10%]
> >>
> >> PID %CPU RUNTIME COMMMAND
> >> ----------------------------------------------------
> >> 0 18.25 341.048 ms swapper/4
> >> 0 17.80 332.691 ms swapper/5
> >> 0 16.89 315.630 ms swapper/2
> >> 2913012 8.99 168.201 ms sched-messaging
> >> 2913021 8.74 163.456 ms sched-messaging
> >> 2913026 8.34 156.120 ms sched-messaging
> >> 2913010 8.14 152.372 ms sched-messaging
> >> 2913007 7.74 144.754 ms sched-messaging
> >> 2913016 7.42 138.977 ms sched-messaging
> >> 2913022 7.28 136.279 ms sched-messaging
> >> 2913013 7.00 130.894 ms sched-messaging
> >> 2913019 6.96 130.455 ms sched-messaging
> >> 2913023 6.91 129.364 ms sched-messaging
> >> 2913008 6.47 121.331 ms sched-messaging
> >> 2913018 6.47 121.124 ms sched-messaging
> >> 2912994 6.42 120.213 ms sched-messaging
> >> 2913025 6.42 120.140 ms sched-messaging
> >> 2913020 6.37 119.386 ms sched-messaging
> >> 2913011 6.35 118.921 ms sched-messaging
> >> 2913014 6.24 116.779 ms sched-messaging
> >> 2913009 6.01 112.661 ms sched-messaging
> >> 2913005 5.96 111.587 ms sched-messaging
> >> 2913003 5.94 111.142 ms sched-messaging
> >> 2913024 5.87 109.876 ms sched-messaging
> >> 2912988 5.84 109.396 ms sched-messaging
> >> 2912987 5.80 108.550 ms sched-messaging
> >> 2912990 5.51 103.322 ms sched-messaging
> >> 2912993 5.45 102.045 ms sched-messaging
> >> 2912996 5.42 101.622 ms sched-messaging
> >> 2913006 5.42 101.592 ms sched-messaging
> >> 2913000 5.41 101.511 ms sched-messaging
> >> 2913002 5.41 101.420 ms sched-messaging
> >> 2912997 5.40 101.315 ms sched-messaging
> >> 2913004 5.33 99.872 ms sched-messaging
> >> 2913015 5.29 99.252 ms sched-messaging
> >> 2913017 5.22 97.822 ms sched-messaging
> >> 2912991 5.11 95.773 ms sched-messaging
> >> 2912992 5.11 95.579 ms sched-messaging
> >> 2913001 5.07 95.033 ms sched-messaging
> >> 2912989 4.93 92.425 ms sched-messaging
> >> 2912995 4.85 90.892 ms sched-messaging
> >> 2912998 4.78 89.617 ms sched-messaging
> >> 2912999 4.56 85.576 ms sched-messaging
> >> 3006112 0.07 1.402 ms redis-server
> >> 660381 0.02 0.566 ms containerd
> >> 2912984 0.02 0.452 ms perf
> >> 659824 0.01 0.369 ms containerd
> >> 659822 0.00 0.316 ms containerd
> >> 10 0.00 0.176 ms rcu_sched
> >> 801 0.00 0.120 ms jbd2/sda4-8
> >> 2912985 0.00 0.107 ms sched-messaging
> >> 2912986 0.00 0.075 ms perf
> >> 2912817 0.00 0.070 ms kworker/2:1
> >> 2912192 0.00 0.056 ms kworker/u24:2
> >> 2929605 0.00 0.046 ms grpc_global_tim
> >> 2902444 0.00 0.046 ms kworker/5:1
> >> 2912951 0.00 0.036 ms kworker/4:3
> >> 42 0.00 0.023 ms ksoftirqd/5
> >> 24 0.00 0.019 ms ksoftirqd/2
> >> 23 0.00 0.011 ms migration/2
> >> 35 0.00 0.010 ms migration/4
> >> 480 0.00 0.009 ms kworker/4:1H
> >> 41 0.00 0.008 ms migration/5
> >> 36 0.00 0.005 ms ksoftirqd/4
> >>
> >> # perf kwork top -n perf
> >>
> >> Total : 22419.068 ms, 12 cpus
> >> %Cpu(s): 17.99% id, 0.00% hi, 0.09% si
> >> %Cpu0 [ 0.00%]
> >> %Cpu1 [ 0.00%]
> >> %Cpu2 [ 0.02%]
> >> %Cpu3 [ 0.00%]
> >> %Cpu4 [ 0.00%]
> >> %Cpu5 [ 0.00%]
> >> %Cpu6 [ 0.00%]
> >> %Cpu7 [ 0.00%]
> >> %Cpu8 [ 0.03%]
> >> %Cpu9 [ 0.09%]
> >> %Cpu10 [ 0.00%]
> >> %Cpu11 [ 1.96%]
> >>
> >> PID %CPU RUNTIME COMMMAND
> >> ----------------------------------------------------
> >> 2912984 2.10 39.452 ms perf
> >> 2912986 0.00 0.075 ms perf
> >>
> >> # perf kwork top -s tid -n sched-messaging
> >>
> >> Total : 22419.068 ms, 12 cpus
> >> %Cpu(s): 17.99% id, 0.00% hi, 0.09% si
> >> %Cpu0 [|||||||||||||||||||||||| 81.80%]
> >> %Cpu1 [|||||||||||||||||||||||| 81.65%]
> >> %Cpu2 [|||||||||||||||||||||||| 82.88%]
> >> %Cpu3 [|||||||||||||||||||||||| 80.96%]
> >> %Cpu4 [|||||||||||||||||||||||| 81.64%]
> >> %Cpu5 [|||||||||||||||||||||||| 82.04%]
> >> %Cpu6 [|||||||||||||||||||||||| 81.63%]
> >> %Cpu7 [|||||||||||||||||||||||| 81.97%]
> >> %Cpu8 [|||||||||||||||||||||||| 82.43%]
> >> %Cpu9 [|||||||||||||||||||||||| 80.86%]
> >> %Cpu10 [|||||||||||||||||||||||| 81.72%]
> >> %Cpu11 [||||||||||||||||||||||| 79.89%]
> >>
> >> PID %CPU RUNTIME COMMMAND
> >> ----------------------------------------------------
> >> 2912985 0.04 1.111 ms sched-messaging
> >> 2912987 21.28 398.512 ms sched-messaging
> >> 2912988 21.44 401.820 ms sched-messaging
> >> 2912989 21.46 402.303 ms sched-messaging
> >> 2912990 21.54 403.601 ms sched-messaging
> >> 2912991 21.59 404.378 ms sched-messaging
> >> 2912992 21.57 403.845 ms sched-messaging
> >> 2912993 21.69 406.166 ms sched-messaging
> >> 2912994 21.52 403.087 ms sched-messaging
> >> 2912995 21.49 402.421 ms sched-messaging
> >> 2912996 21.48 402.666 ms sched-messaging
> >> 2912997 21.27 398.518 ms sched-messaging
> >> 2912998 21.75 407.579 ms sched-messaging
> >> 2912999 21.79 407.929 ms sched-messaging
> >> 2913000 21.78 408.045 ms sched-messaging
> >> 2913001 21.55 403.803 ms sched-messaging
> >> 2913002 21.27 398.759 ms sched-messaging
> >> 2913003 21.46 402.034 ms sched-messaging
> >> 2913004 21.37 400.242 ms sched-messaging
> >> 2913005 21.56 403.715 ms sched-messaging
> >> 2913006 21.23 397.888 ms sched-messaging
> >> 2913007 27.48 514.411 ms sched-messaging
> >> 2913008 27.54 515.447 ms sched-messaging
> >> 2913009 27.30 510.997 ms sched-messaging
> >> 2913010 27.50 514.890 ms sched-messaging
> >> 2913011 27.32 511.632 ms sched-messaging
> >> 2913012 27.30 511.138 ms sched-messaging
> >> 2913013 27.30 511.109 ms sched-messaging
> >> 2913014 27.32 511.381 ms sched-messaging
> >> 2913015 27.36 512.563 ms sched-messaging
> >> 2913016 27.18 509.231 ms sched-messaging
> >> 2913017 27.56 516.273 ms sched-messaging
> >> 2913018 27.56 516.152 ms sched-messaging
> >> 2913019 27.25 510.488 ms sched-messaging
> >> 2913020 27.20 509.677 ms sched-messaging
> >> 2913021 27.23 509.661 ms sched-messaging
> >> 2913022 27.19 509.061 ms sched-messaging
> >> 2913023 27.21 509.400 ms sched-messaging
> >> 2913024 27.18 509.108 ms sched-messaging
> >> 2913025 27.62 516.976 ms sched-messaging
> >> 2913026 27.35 512.198 ms sched-messaging
> >>
> >> # perf kwork top -b
> >> Starting trace, Hit <Ctrl+C> to stop and report
> >> ^C
> >> Total : 89209.004 ms, 4 cpus
> >> %Cpu(s): 13.47% id, 0.01% hi, 0.24% si
> >> %Cpu0 [||||||||||||||||||||||||| 86.08%]
> >> %Cpu1 [|||||||||||||||||||||||||| 87.08%]
> >> %Cpu2 [||||||||||||||||||||||||| 86.10%]
> >> %Cpu3 [||||||||||||||||||||||||| 85.86%]
> >>
> >> PID SPID %CPU RUNTIME COMMMAND
> >> -------------------------------------------------------------
> >> 0 0 13.86 3092.482 ms [swapper/3]
> >> 0 0 13.71 3057.756 ms [swapper/0]
> >> 0 0 13.65 3044.987 ms [swapper/2]
> >> 0 0 12.63 2818.079 ms [swapper/1]
> >> 320 320 1.32 295.427 ms bash
> >> 414 320 1.09 247.658 ms sched-messaging
> >> 678 320 1.09 246.881 ms sched-messaging
> >> 354 320 1.09 246.683 ms sched-messaging
> >> 409 320 1.08 246.839 ms sched-messaging
> >> 554 320 1.07 243.045 ms sched-messaging
> >> 405 320 1.04 237.340 ms sched-messaging
> >> 525 320 1.04 235.718 ms sched-messaging
> >> 486 320 1.03 235.369 ms sched-messaging
> >> 714 320 1.03 235.142 ms sched-messaging
> >> 435 320 1.03 233.290 ms sched-messaging
> >> 408 320 1.03 231.687 ms sched-messaging
> >> 716 320 1.02 233.513 ms sched-messaging
> >> 453 320 1.02 233.181 ms sched-messaging
> >> 522 320 1.02 230.101 ms sched-messaging
> >> 651 320 1.02 229.554 ms sched-messaging
> >> 418 320 1.01 231.359 ms sched-messaging
> >> 644 320 1.01 229.848 ms sched-messaging
> >> 535 320 1.01 229.655 ms sched-messaging
> >> 536 320 1.01 229.147 ms sched-messaging
> >> 410 320 1.01 227.700 ms sched-messaging
> >> 689 320 1.00 227.988 ms sched-messaging
> >> 412 320 1.00 227.052 ms sched-messaging
> >> 489 320 1.00 226.374 ms sched-messaging
> >> 521 320 1.00 225.499 ms sched-messaging
> >> 530 320 1.00 225.262 ms sched-messaging
> >> 681 320 1.00 225.187 ms sched-messaging
> >> 415 320 0.99 225.714 ms sched-messaging
> >> 643 320 0.99 225.090 ms sched-messaging
> >> 325 320 0.99 223.385 ms sched-messaging
> >> 498 320 0.99 222.936 ms sched-messaging
> >> 413 320 0.98 225.213 ms sched-messaging
> >> 645 320 0.98 223.211 ms sched-messaging
> >> 544 320 0.98 222.714 ms sched-messaging
> >> 441 320 0.98 222.590 ms sched-messaging
> >> 697 320 0.98 222.426 ms sched-messaging
> >> 523 320 0.98 221.841 ms sched-messaging
> >> 402 320 0.98 221.776 ms sched-messaging
> >> <SNIP>
> >>
> >> Yang Jihong (16):
> >> perf kwork: Fix incorrect and missing free atom in work_push_atom()
> >> perf kwork: Add the supported subcommands to the document
> >> perf kwork: Set ordered_events for perf_tool
> >> perf kwork: Add `kwork` and `src_type` to work_init() for struct
> >> kwork_class
> >> perf kwork: Overwrite original atom in the list when a new atom is
> >> pushed.
> >> perf kwork: Set default events list if not specified in
> >> setup_event_list()
> >> perf kwork: Add sched record support
> >> perf kwork: Add `root` parameter to work_sort()
> >> perf kwork: Implement perf kwork top
> >> perf evsel: Add evsel__intval_common() helper
> >> perf kwork top: Add statistics on hardirq event support
> >> perf kwork top: Add statistics on softirq event support
> >> perf kwork top: Add -C/--cpu -i/--input -n/--name -s/--sort --time
> >> options
> >> perf kwork top: Implements BPF-based cpu usage statistics
> >> perf kwork top: Add BPF-based statistics on hardirq event support
> >> perf kwork top: Add BPF-based statistics on softirq event support
> >
> > Besides documentation nits, series:
> > Reviewed-by: Ian Rogers <irogers@...gle.com>
>
> Thanks for reivew.
>
> >
> > Whilst looking at the series, could we clean up
> > tools/perf/util/kwork.h ? Generally none of the structs are commented.
>
> Okay, I'll put up a separate patch and add comments about it.
> > Some like:
> > > struct kwork_atom {
> > struct list_head list;
> > u64 time;
> > struct kwork_atom *prev;
> >
> > void *page_addr;
> > unsigned long bit_inpage;
> > };
> >
> > Why is it an atom? Why is there a prev when the kwork_atom is also on
> > a list (which has a prev) ?
> >
> An atom indicates a minimum granularity event.
> For example, an "irq_hander_entry" event of an IRQ whose irqnum==10 is
> an atom.
>
> The prev member is used to store the sequence of events.
> For example, the sequence of events is as follows:
> raise -> entry -> exit
>
> Then:
> entry_atom->prev = raise_atom
>
> This relationship needs to be saved because need to calculate latency
> time and running time at the same time in the "perf kwork timehist"
Thanks Yang, this is good context. Could it be added to the header
file? I'm also wondering at some point we should start generating
kerneldoc from comments in the code. I don't know if you want to look
into kerneldoc style comments.
Thanks,
Ian
> Thanks,
> Yang
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