Re: [PATCH 05/14] perf tools: Add parse_events_fake interface

From: Ian Rogers <irogers@google.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Michael Petlan <mpetlan@redhat.com>,
	Stephane Eranian <eranian@google.com>,
	Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 05/14] perf tools: Add parse_events_fake interface
Date: Mon, 1 Jun 2020 00:28:31 -0700	[thread overview]
Message-ID: <CAP-5=fXaRv3rbjUYoTJUgc+GfnLku--O5LiHrM1W3ofaFz28rQ@mail.gmail.com> (raw)
In-Reply-To: <20200524224219.234847-6-jolsa@kernel.org>

On Sun, May 24, 2020 at 3:42 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> Adding parse_events_fake interface to parse events
> and use fake pmu event in case pmu event is parsed.
>
> This way it's possible to parse events from PMUs
> which are not present in the system. It's available
> only for testing purposes coming in following
> changes.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Acked-by: Ian Rogers <irogers@google.com>

Alternatively fake_pmu could be an argument to parse_events.

Thanks,
Ian

> ---
>  tools/perf/util/parse-events.c | 48 +++++++++++++++++++++++++---------
>  tools/perf/util/parse-events.h |  2 ++
>  2 files changed, 37 insertions(+), 13 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 8304f9b6e6be..89239695a728 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -2082,22 +2082,15 @@ int parse_events_terms(struct list_head *terms, const char *str)
>         return ret;
>  }
>
> -int parse_events(struct evlist *evlist, const char *str,
> -                struct parse_events_error *err)
> +static int parse_events_state(struct parse_events_state *parse_state,
> +                             struct evlist *evlist, const char *str)
>  {
> -       struct parse_events_state parse_state = {
> -               .list   = LIST_HEAD_INIT(parse_state.list),
> -               .idx    = evlist->core.nr_entries,
> -               .error  = err,
> -               .evlist = evlist,
> -               .stoken = PE_START_EVENTS,
> -       };
>         int ret;
>
> -       ret = parse_events__scanner(str, &parse_state);
> +       ret = parse_events__scanner(str, parse_state);
>         perf_pmu__parse_cleanup();
>
> -       if (!ret && list_empty(&parse_state.list)) {
> +       if (!ret && list_empty(&parse_state->list)) {
>                 WARN_ONCE(true, "WARNING: event parser found nothing\n");
>                 return -1;
>         }
> @@ -2105,12 +2098,12 @@ int parse_events(struct evlist *evlist, const char *str,
>         /*
>          * Add list to the evlist even with errors to allow callers to clean up.
>          */
> -       perf_evlist__splice_list_tail(evlist, &parse_state.list);
> +       perf_evlist__splice_list_tail(evlist, &parse_state->list);
>
>         if (!ret) {
>                 struct evsel *last;
>
> -               evlist->nr_groups += parse_state.nr_groups;
> +               evlist->nr_groups += parse_state->nr_groups;
>                 last = evlist__last(evlist);
>                 last->cmdline_group_boundary = true;
>
> @@ -2125,6 +2118,35 @@ int parse_events(struct evlist *evlist, const char *str,
>         return ret;
>  }
>
> +int parse_events(struct evlist *evlist, const char *str,
> +                struct parse_events_error *err)
> +{
> +       struct parse_events_state parse_state = {
> +               .list   = LIST_HEAD_INIT(parse_state.list),
> +               .idx    = evlist->core.nr_entries,
> +               .error  = err,
> +               .evlist = evlist,
> +               .stoken = PE_START_EVENTS,
> +       };
> +
> +       return parse_events_state(&parse_state, evlist, str);
> +}
> +
> +int parse_events_fake(struct evlist *evlist, const char *str,
> +                     struct parse_events_error *err)
> +{
> +       struct parse_events_state parse_state = {
> +               .list     = LIST_HEAD_INIT(parse_state.list),
> +               .idx      = evlist->core.nr_entries,
> +               .error    = err,
> +               .evlist   = evlist,
> +               .stoken   = PE_START_EVENTS,
> +               .fake_pmu = true,
> +       };
> +
> +       return parse_events_state(&parse_state, evlist, str);
> +}
> +
>  #define MAX_WIDTH 1000
>  static int get_term_width(void)
>  {
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index 963b0ea6c448..4a23b6cd9924 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -34,6 +34,8 @@ int parse_events_option(const struct option *opt, const char *str, int unset);
>  int parse_events_option_new_evlist(const struct option *opt, const char *str, int unset);
>  int parse_events(struct evlist *evlist, const char *str,
>                  struct parse_events_error *error);
> +int parse_events_fake(struct evlist *evlist, const char *str,
> +                     struct parse_events_error *error);
>  int parse_events_terms(struct list_head *terms, const char *str);
>  int parse_filter(const struct option *opt, const char *str, int unset);
>  int exclude_perf(const struct option *opt, const char *arg, int unset);
> --
> 2.25.4
>