Re: [PATCH] app/dma-perf: add average latency per worker

["Varghese, Vipin" <vipin.varghese@amd.com>]

On 2/27/2024 6:39 PM, fengchengwen wrote:
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>
>
> Hi Vipin,
>
> On 2024/2/27 17:50, Varghese, Vipin wrote:
>> On 2/23/2024 3:15 PM, fengchengwen wrote:
>>> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>>>
>>>
>>> Hi Vipin,
>>>
>>> On 2023/12/20 0:40, Vipin Varghese wrote:
>>>> Modify the user display data with total average latency per worker.
>>>>
>>>> Signed-off-by: Vipin Varghese <vipin.varghese@amd.com>
>>>> ---
>>>>    app/test-dma-perf/benchmark.c | 3 ++-
>>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/app/test-dma-perf/benchmark.c b/app/test-dma-perf/benchmark.c
>>>> index 9b1f58c78c..8b6886af62 100644
>>>> --- a/app/test-dma-perf/benchmark.c
>>>> +++ b/app/test-dma-perf/benchmark.c
>>>> @@ -470,7 +470,8 @@ mem_copy_benchmark(struct test_configure *cfg, bool is_dma)
>>>>                 bandwidth_total += bandwidth;
>>>>                 avg_cycles_total += avg_cycles;
>>>>         }
>>>> -     printf("\nTotal Bandwidth: %.3lf Gbps, Total MOps: %.3lf\n", bandwidth_total, mops_total);
>>>> +     printf("\nAverage Cycles/op: %.2lf, Total Bandwidth: %.3lf Gbps, Total MOps: %.3lf\n",
>>>> +                     (float) avg_cycles_total / nb_workers, bandwidth_total, mops_total);
>> thanks for the suggestions, please find my observations below
>>
>>> Because this is total stats, suggest add Total prefix, e.g. "Total Average Cycles/op"
>> I did not follow this, so please let me try to explain my understanding. For `n` operation we count the average cycles, then
>> we add the cycles to form `total average cycles`; this is then divide by `n` operations. Making this per operation what is the
>> average cycles taken for the round trip time. Hence `Total Average Cyeles/op` does not sound right, but `Average Cycles / op` does.
> OK
> My intention was to differentiate (since they have the same beginning).
>
>>> I think print format keep one-digit precision is enough. Also please modify CSV_TOTAL_LINE_FMT
>>> make sure the csv also have same precision of Cycles/op.
>> We have checked the CSV formatting a find
>> 1. the precision for average cycle/op is 2 digits precision.
>> 2. already the CVS format has average cycles/op integrated.
>>
>> Hence no change is required.
> It's weird.
>
> We can see more clear when add together:
> #define CSV_TOTAL_LINE_FMT "Scenario %u Summary, , , , , ,%u,%.2lf,%u,%.3lf,%.3lf\n"
>          snprintf(output_str[MAX_WORKER_NB], MAX_OUTPUT_STR_LEN, CSV_TOTAL_LINE_FMT,
>                          cfg->scenario_id, nr_buf, memory * nb_workers,
>                          avg_cycles_total / nb_workers, bandwidth_total, mops_total);
> The bandwidth_total, mops_total both are float, which take last two "%.31f", then "%u" is for "avg_cycles_total / nb_workers"
>
> Also, avg_cycles_total / nb_workers both are u32, and its result is u32 if not with force convert.
>
> You could modify with "avg_cycles_total*1.0 / nb_workers", then compile will output warning:
>
> [2035/3727] Compiling C object app/dpdk-test-dma-perf.p/test-dma-perf_benchmark.c.o
> ../../dpdk/app/test-dma-perf/benchmark.c: In function ‘mem_copy_benchmark’:
> ../../dpdk/app/test-dma-perf/benchmark.c:26:28: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 7 has type ‘double’ [-Wformat=]
>   #define CSV_TOTAL_LINE_FMT "Scenario %u Summary, , , , , ,%u,%.2lf,%u,%.3lf,%.3lf\n"

thank you Chengwen, let me share v2 for this patch with both print and 
csv in same format.


>
> Thanks
>                              ^
>>> Thanks
>>>
>>>>         snprintf(output_str[MAX_WORKER_NB], MAX_OUTPUT_STR_LEN, CSV_TOTAL_LINE_FMT,
>>>>                         cfg->scenario_id, nr_buf, memory * nb_workers,
>>>>                         avg_cycles_total / nb_workers, bandwidth_total, mops_total);
>>>>
>> .