[PATCH v2 1/5] app/testpmd: add trace save command

[Ferruh Yigit]

On 6/23/2023 1:03 PM, Jerin Jacob wrote:
> On Fri, Jun 23, 2023 at 5:23 PM Ferruh Yigit <ferruh.yigit at amd.com> wrote:
>>
>> On 6/23/2023 9:00 AM, Slava Ovsiienko wrote:
>>> Hi, Ferruh
>>>
>>>> -----Original Message-----
>>>> From: Ferruh Yigit <ferruh.yigit at amd.com>
>>>> Sent: Wednesday, June 21, 2023 2:16 PM
>>>> To: Slava Ovsiienko <viacheslavo at nvidia.com>; dev at dpdk.org; Aman Singh
>>>> <aman.deep.singh at intel.com>
>>>> Cc: Jerin Jacob Kollanukkaran <jerinj at marvell.com>
>>>> Subject: Re: [PATCH v2 1/5] app/testpmd: add trace save command
>>>>
>>>> On 6/13/2023 5:58 PM, Viacheslav Ovsiienko wrote:
>>>>> The "save_trace" CLI command is added to trigger saving the trace
>>>>> dumps to the trace directory.
>>>>>
>>>>
>>>> Hi Viacheslav,
>>>>
>>>> Trace is already saved when dpdk application terminated, I guess this is to
>>>> save the trace before exiting the application, what is the use case for this, can
>>>> you please detail in the commit log.
>>>
>>> OK, will update the commit log. The command "save_trace" is useful in some
>>> dynamic debug scenarios to save the trace without restarting the entire application.
>>>
>>>>
>>>> And what happens if this is called multiple times, or what happens on the
>>>> application exit, will it overwrite the file or fail?
>>> It overwrites.
>>>
>>>> Again please explain in the commit log.
>>> Sure, will do.
>>>
>>>>
>>>>> Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
>>>>> ---
>>>>>  app/test-pmd/cmdline.c | 38 ++++++++++++++++++++++++++++++++++++++
>>>>>  1 file changed, 38 insertions(+)
>>>>>
>>>>
>>>> Can you please update documentation too?
>>>>
>>>>> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
>>>>> a15a442a06..db71ce2028 100644
>>>>> --- a/app/test-pmd/cmdline.c
>>>>> +++ b/app/test-pmd/cmdline.c
>>>>> @@ -39,6 +39,7 @@
>>>>>  #include <rte_gro.h>
>>>>>  #endif
>>>>>  #include <rte_mbuf_dyn.h>
>>>>> +#include <rte_trace.h>
>>>>>
>>>>>  #include <cmdline_rdline.h>
>>>>>  #include <cmdline_parse.h>
>>>>> @@ -12745,6 +12746,40 @@ static cmdline_parse_inst_t
>>>> cmd_config_tx_affinity_map = {
>>>>>     },
>>>>>  };
>>>>>
>>>>> +#ifndef RTE_EXEC_ENV_WINDOWS
>>>>> +/* *** SAVE_TRACE *** */
>>>>> +
>>>>> +struct cmd_save_trace_result {
>>>>> +   cmdline_fixed_string_t save;
>>>>> +};
>>>>> +
>>>>> +static void cmd_save_trace_parsed(__rte_unused void *parsed_result,
>>>>> +                             __rte_unused struct cmdline *cl,
>>>>> +                             __rte_unused void *data)
>>>>> +{
>>>>> +   int rc;
>>>>> +
>>>>> +   rc = rte_trace_save();
>>>>> +   if (rc)
>>>>> +           printf("Save trace failed with error: %d\n", rc);
>>>>> +   else
>>>>> +           printf("Trace saved successfully\n"); }
>>>>> +
>>>>> +static cmdline_parse_token_string_t cmd_save_trace_save =
>>>>> +   TOKEN_STRING_INITIALIZER(struct cmd_save_trace_result, save,
>>>>> +"save_trace");
>>>>> +
>>>>
>>>> We have dump_* commands, what do you think to have 'dump_trace'
>>>> command for this?
>>> It was initially (in v1) with "dump_trace" command.
>>> And there is the comment by Jerin:
>>> https://inbox.dpdk.org/dev/CALBAE1Of79a_jHnFT3KX--Enhud-h5RzL02TMQBsmoW721ds7A@mail.gmail.com/#t
>>>
>>> So, I have changed to "save_trace". I have no strong opinion about command name, any allowing trace save is OK for me.
>>>
>>
>> Ah, I missed that.
>>
>>
>> @Jerin,
>> I just saw your comment, agree more exact action can be 'save' but
>> 'dump' also describes enough.
>> Since there are existing 'dump_*' commands, it makes command more
>> intuitive and easy to remember.
>>
>> As an active user of testpmd myself, I am finding it hard to
>> remember/find the command I need as number of commands increased. That
>> is why I am paying extra attention to have more hierarchical, consistent
>> and intuitive commands.
>>
>> For me "dump_trace" works better in that manner, what do you think, do
>> you have strong opinion on 'save_trace'?
> 
> dump_* commands dumping on stdout or FILE.
> Trace is mostly saving "current trace buffer" it and internally it
> figure out the FILE.
>

Agree that 'save' can be more accurate, but 'dump_*' is more consistent.
Saving trace buffer to a file, or dumping content of trace buffer to a
file, looks close enough to me.

> But no strong opinion, if testpmd user thinks "dump" is better.
> 

OK, lets continue with 'dump_trace'.