Re: [RFC] perf: probe_finder: continue if atleast one probe point found

[Joel Fernandes]

Sorry about the line wrapping, I sent this email through g-mail.
Shouldn't have any issue when I send the final patch through git
send-email.

Thanks,
Joel

On Tue, Mar 1, 2016 at 2:34 AM, Joel Fernandes <agnel.joel@xxxxxxxxx> wrote:
> Hi Hiramatu,
>
> On Mon, Feb 29, 2016 at 8:29 PM, åæéå / HIRAMATUïMASAMI
> <masami.hiramatsu.pt@xxxxxxxxxxx> wrote:
>> BTW,
>>
>> ./perf probe  \
>>   -k ./vmlinux -s ./ -x /lib/x86_64-linux-gnu/libc.so.6 -a 'malloc $params'
>>
>> might help your case. $params is expanded to function parameters automatically
>> and if there is no parameters, it is just ignored :)
>
> Thanks, I agree this is a better approach.
>
> How about an informative error letting the user know about it? Is the
> below Ok? I can send a patch.
>
> ----x8--------
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 4ce5c5e..21f282a 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -1247,8 +1247,12 @@ static int add_probe_trace_event(Dwarf_Die
> *sc_die, struct probe_finder *pf)
>                 pf->tvar = &tev->args[i];
>                 /* Variable should be found from scope DIE */
>                 ret = find_variable(sc_die, pf);
> -               if (ret != 0)
> +               if (ret != 0) {
> +                       pr_err("Variable couldn't be found, if probe
> is on inline function,"
> +                              "try '%s' or '%s' instead.\n",
> +                              PROBE_ARG_PARAMS, PROBE_ARG_VARS);
>                         break;
> +               }
>         }