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

[Slava Ovsiienko <viacheslavo@nvidia.com>]

Hi, Ferruh

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@amd.com>
> Sent: Wednesday, June 21, 2023 2:16 PM
> To: Slava Ovsiienko <viacheslavo@nvidia.com>; dev@dpdk.org; Aman Singh
> <aman.deep.singh@intel.com>
> Cc: Jerin Jacob Kollanukkaran <jerinj@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@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.

With best regards,
Slava