Re: [PATCH 2/2] perf lock info: Enforce exactly one of --map and --thread

[Nick Forrington]

On 08/11/2023 20:28, Arnaldo Carvalho de Melo wrote:
> Em Wed, Nov 01, 2023 at 11:00:42PM -0700, Namhyung Kim escreveu:
> > On Wed, Nov 1, 2023 at 7:35 AM Nick Forrington <nick.forrington@xxxxxxx> wrote:
> > > On 31/10/2023 15:38, Arnaldo Carvalho de Melo wrote:
> > > > Em Tue, Oct 31, 2023 at 12:05:25PM +0000, Nick Forrington escreveu:
> > > > > Improve error reporting for command line arguments.
> > > > >
> > > > > Display error/usage if neither --map or --thread are specified (rather
> > > > > than a non user-friendly error "Unknown type of information").
> > > > >
> > > > > Display error/usage if both --map and --thread are specified (rather
> > > > > than ignoring "--map" and displaying only thread information).
> > > > Shouldn't one of them be the default so that we type less for the most
> > > > common usage?
> > > >
> > > > - Arnaldo
> > > There isn't an obvious choice (to me) for which would be the default.
> > >
> > > Both options display completely different data/outputs, so I think it
> > > makes sense to be explicit about which data is requested.
> > Maybe we can default to display both. :)
> Yeah, that would be a better approach, I think.
>
> - Arnaldo
>   


I'll submit an updated series for this, with the next update to patch 1/2

Thanks,
Nick

> > Thanks,
> > Namhyung
> >
> > > An alternative could be to use sub-commands e.g. "perf lock info
> > > threads" or just "perf lock threads", although changing the existing
> > > options would be more disruptive.
> > >
> > >
> > > Cheers,
> > > Nick
> > >
> > > > > Signed-off-by: Nick Forrington <nick.forrington@xxxxxxx>
> > > > > ---
> > > > >    tools/perf/builtin-lock.c | 25 +++++++++++++++++++++++++
> > > > >    1 file changed, 25 insertions(+)
> > > > >
> > > > > diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> > > > > index 3aa8ba5ad928..cf29f648d291 100644
> > > > > --- a/tools/perf/builtin-lock.c
> > > > > +++ b/tools/perf/builtin-lock.c
> > > > > @@ -2021,6 +2021,27 @@ static int check_lock_report_options(const struct option *options,
> > > > >       return 0;
> > > > >    }
> > > > >
> > > > > +static int check_lock_info_options(const struct option *options,
> > > > > +                               const char * const *usage)
> > > > > +{
> > > > > +    if (!info_map && !info_threads) {
> > > > > +            pr_err("Requires one of --map or --threads\n");
> > > > > +            parse_options_usage(usage, options, "map", 0);
> > > > > +            parse_options_usage(NULL, options, "threads", 0);
> > > > > +            return -1;
> > > > > +
> > > > > +    }
> > > > > +
> > > > > +    if (info_map && info_threads) {
> > > > > +            pr_err("Cannot show map and threads together\n");
> > > > > +            parse_options_usage(usage, options, "map", 0);
> > > > > +            parse_options_usage(NULL, options, "threads", 0);
> > > > > +            return -1;
> > > > > +    }
> > > > > +
> > > > > +    return 0;
> > > > > +}
> > > > > +
> > > > >    static int check_lock_contention_options(const struct option *options,
> > > > >                                        const char * const *usage)
> > > > >
> > > > > @@ -2709,6 +2730,10 @@ int cmd_lock(int argc, const char **argv)
> > > > >                       if (argc)
> > > > >                               usage_with_options(info_usage, info_options);
> > > > >               }
> > > > > +
> > > > > +            if (check_lock_info_options(info_options, info_usage) < 0)
> > > > > +                    return -1;
> > > > > +
> > > > >               /* recycling report_lock_ops */
> > > > >               trace_handler = &report_lock_ops;
> > > > >               rc = __cmd_report(true);
> > > > > --
> > > > > 2.42.0