Re: [PATCH v2 1/3] tools/lib/traceevent, tools/perf: Changes in tep_print_event_* APIs

[Tzvetomir Stoyanov <tz.stoyanov@gmail.com>]

On Tue, Jul 30, 2019 at 7:12 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Tue, 30 Jul 2019 15:50:26 +0300
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
...
> >  }
> >
> > @@ -5413,18 +5419,20 @@ int tep_cmdline_pid(struct tep_handle *tep, struct tep_cmdline *cmdline)
> >  /**
> >   * tep_event_info - parse the data into the print format
> >   * @s: the trace_seq to write to
> > + * @format: printf format string. If any precision is specified in the string,
> > + *       print in raw data format
>
> I'm curious to why this is needed?
>
> We can use a temp trace_seq like I mentioned above, and then apply the
> format to it at the end.
>
We need a way to keep the tep_set_print_raw() functionality with the
new tep_print_event() API.
The user should have an option to print TEP_PRINT_INFO in raw format.
The only way to pass some
extra parameters to tep_print_event() is to use the printf format
string, "%s" in this case.
I choose to use "%s" width specifier to force TEP_PRINT_INFO in raw format.
The other possible solution could be to define a new
TEP_PRINT_INFO_RAW type for this use case.
...

-- 
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center