On 5/18/2020 10:49 PM, Dharmik Thakkar wrote: > > >> On May 18, 2020, at 4:47 AM, Ferruh Yigit <ferruh.yi...@intel.com> wrote: >> >> On 5/15/2020 9:33 PM, Dharmik Thakkar wrote: >>> Hi Ferruh, >>> >>>> On May 15, 2020, at 7:15 AM, Ferruh Yigit <ferruh.yi...@intel.com> wrote: >>>> >>>> On 5/8/2020 11:38 PM, Dharmik Thakkar wrote: >>>>> Update documentation for 'show fwd' testpmd runtime function to show >>>>> CPU cycles/packet example. >>>>> >>>>> Signed-off-by: Dharmik Thakkar <dharmik.thak...@arm.com> >>>>> Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com> >>>>> Reviewed-by: Phil Yang <phil.y...@arm.com> >>>>> --- >>>>> v2: >>>>> - Use shorter lines, up to 100. >>>>> --- >>>>> doc/guides/testpmd_app_ug/testpmd_funcs.rst | 53 +++++++++++++-------- >>>>> 1 file changed, 33 insertions(+), 20 deletions(-) >>>>> >>>>> diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst >>>>> b/doc/guides/testpmd_app_ug/testpmd_funcs.rst >>>>> index a360ecccfd3f..441ed41e3803 100644 >>>>> --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst >>>>> +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst >>>>> @@ -351,26 +351,39 @@ Example for the io forwarding engine, with some >>>>> packet drops on the tx side:: >>>>> >>>>> testpmd> show fwd stats all >>>>> >>>>> - ------- Forward Stats for RX Port= 0/Queue= 0 -> TX Port= 1/Queue= >>>>> 0 ------- >>>>> - RX-packets: 274293770 TX-packets: 274293642 TX-dropped: >>>>> 128 >>>>> - >>>>> - ------- Forward Stats for RX Port= 1/Queue= 0 -> TX Port= 0/Queue= >>>>> 0 ------- >>>>> - RX-packets: 274301850 TX-packets: 274301850 TX-dropped: 0 >>>>> - >>>>> - ---------------------- Forward statistics for port 0 >>>>> ---------------------- >>>>> - RX-packets: 274293802 RX-dropped: 0 RX-total: >>>>> 274293802 >>>>> - TX-packets: 274301862 TX-dropped: 0 TX-total: >>>>> 274301862 >>>>> - >>>>> ---------------------------------------------------------------------------- >>>>> - >>>>> - ---------------------- Forward statistics for port 1 >>>>> ---------------------- >>>>> - RX-packets: 274301894 RX-dropped: 0 RX-total: >>>>> 274301894 >>>>> - TX-packets: 274293706 TX-dropped: 128 TX-total: >>>>> 274293834 >>>>> - >>>>> ---------------------------------------------------------------------------- >>>>> - >>>>> - +++++++++++++++ Accumulated forward statistics for all >>>>> ports+++++++++++++++ >>>>> - RX-packets: 548595696 RX-dropped: 0 RX-total: >>>>> 548595696 >>>>> - TX-packets: 548595568 TX-dropped: 128 TX-total: >>>>> 548595696 >>>>> - >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> + ------- Forward Stats for RX Port= 0/Queue= 0 -> TX Port= 1/Queue= >>>>> 0 ------- >>>>> + RX-packets: 43536504 TX-packets: 43536488 TX-dropped: 0 >>>>> + >>>>> + ------- Forward Stats for RX Port= 1/Queue= 0 -> TX Port= 0/Queue= >>>>> 0 ------- >>>>> + RX-packets: 149738504 TX-packets: 149738504 TX-dropped: 0 >>>>> + >>>>> + ------- Forward Stats for RX Port= 1/Queue= 1 -> TX Port= 0/Queue= >>>>> 1 ------- >>>>> + RX-packets: 149753052 TX-packets: 149753052 TX-dropped: 0 >>>>> + >>>>> + ---------------------- Forward statistics for port 0 >>>>> ---------------------- >>>>> + RX-packets: 43538881 RX-dropped: 72 RX-total: >>>>> 43538953 >>>>> + TX-packets: 299491753 TX-dropped: 0 TX-total: >>>>> 299491753 >>>>> + >>>>> ---------------------------------------------------------------------------- >>>>> + >>>>> + ---------------------- Forward statistics for port 1 >>>>> ---------------------- >>>>> + RX-packets: 299493085 RX-dropped: 8357 RX-total: >>>>> 299501442 >>>>> + TX-packets: 43539683 TX-dropped: 0 TX-total: >>>>> 43539683 >>>>> + >>>>> ---------------------------------------------------------------------------- >>>>> + >>>>> + +++++++++++++++ Accumulated forward statistics for all >>>>> ports+++++++++++++++ >>>>> + RX-packets: 343031966 RX-dropped: 8429 RX-total: >>>>> 343040395 >>>>> + TX-packets: 343031436 TX-dropped: 0 TX-total: >>>>> 343031436 >>>>> + >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> + >>>>> + CPU cycles/packet=14.28 (total cycles=4899533541 / total RX >>>>> packets=343031966) at 200 MHz Clock >>>> >>>> Hi Dharmik, >>>> >>>> Overall it is OK to show "CPU cycles/packet", but my concern is numbers >>>> can be >>>> misleading, because for example the numbers I am getting is like below: >>>> >>>> CPU cycles/packet=4.38 (total cycles=32871036274 / total RX >>>> packets=7511734336) >>>> at 2100 MHz Clock >>> >>> CPU cycles/packet shown above is a part of the example. The numbers are as >>> per the statistics shown in the example. >> >> I know but now you are showing a performance number and it is specific to a >> platform, my concern it may be misleading and create false expectations for >> others. > > Ok, makes sense. > >> >>> >>>> >>>>> + >>>>> +.. note:: >>>>> + >>>>> + Measuring CPU cycles/packet requires enabling >>>>> CONFIG_RTE_TEST_PMD_RECORD_CORE_TX_CYCLES >>>> >>>> s/TX_CYCLES/CYCLES >>> >>> Sorry, didn’t understand this comment. >> >> There is no 'CONFIG_RTE_TEST_PMD_RECORD_CORE_TX_CYCLES' config option. > > Got it, will update. > >> >>> >>>> >>>>> + configuration option. On aarch64 platforms, by default, the cycles >>>>> are counted using >>>>> + generic counter which runs at a lower frequency than the CPU clock. >>>>> To get the cycles/packet >>>>> + at CPU clock frequency, please scale the cycles/packet to CPU clock >>>>> frequency. >>>>> + Alternatively, use the PMU based cycle counter. >>>> >>>> Not sure the "aarch64 platforms" note suits to here, where documents the >>>> command. And I can see the platform documentation already updated for this. >>> >>> This additional comment about aarch64 platforms is to provide complete >>> information to the users with regards to the config option >>> and offer a better understanding of the CPU cycles/packet numbers. IMO, >>> without this note, CPU cycles/packet numbers can be misleading. >> >> This is testpmd documentation to describe "show fwd stats" command. We are >> adding a note to say with a config option it may also show performance data, >> which is OK. But starting to describe the platform differences for this >> config >> option looks to much details for the scope of the document. For testpmd I >> would >> prefer command usage independent from platforms, otherwise the documentation >> may >> become too confusing/complex. >> But agree to provide the information for the specific platform, which you are >> already doing in other patch in the platform documentation. > > Alright, I will remove platform in the next version. > >> >>> >>>> >>>> Combining above two comments, what do you think instead of replacing >>>> existing >>>> stats, add a note saying enabling 'CONFIG_RTE_TEST_PMD_RECORD_CORE_CYCLES' >>>> appends "CPU cycles/packet" and give above two samples, like: >>>> >>>> " >>>> Enabling RTE_TEST_PMD_RECORD_CORE_CYCLES appends "CPU cycles/packet" >>>> stats, like: >>>> >>>> CPU cycles/packet=4.38 (total cycles=32871036274 / total RX >>>> packets=7511734336) >>>> at 2100 MHz Clock >>>> OR >>>> CPU cycles/packet=14.28 (total cycles=4899533541 / total RX >>>> packets=343031966) >>>> at 200 MHz Clock >>>> " >>> >>> Yes, this is also an option. IMO, numbers shown within CPU cycles/packet >>> example should be consistent with the forward statistics numbers. >>> >> >> This part is just the sample of the "CPU cycles/packet" output, I think it >> provides enough context to be understandable without matching Rx packet >> count in >> above part of the stats. > > Instead of adding 2 samples, do you think using xxx is best? For example: > CPU cycles/packet=xx.dd (total cycles=xxxx / total RX packets=xxxx) at xxxx > MHz clock >
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