Re: [PATCH 3/7] perf metricgroup: Delay events string creation

From: Ian Rogers
Date: Wed May 20 2020 - 14:22:52 EST


On Wed, May 20, 2020 at 6:14 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Wed, May 20, 2020 at 12:28:10AM -0700, Ian Rogers wrote:
> > Currently event groups are placed into groups_list at the same time as
> > the events string containing the events is built. Separate these two
> > operations and build the groups_list first, then the event string from
> > the groups_list. This adds an ability to reorder the groups_list that
> > will be used in a later patch.
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> > tools/perf/util/metricgroup.c | 38 +++++++++++++++++++++++------------
> > 1 file changed, 25 insertions(+), 13 deletions(-)
> >
> > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > index 7a43ee0a2e40..afd960d03a77 100644
> > --- a/tools/perf/util/metricgroup.c
> > +++ b/tools/perf/util/metricgroup.c
> > @@ -90,6 +90,7 @@ struct egroup {
> > const char *metric_expr;
> > const char *metric_unit;
> > int runtime;
> > + bool has_constraint;
> > };
> >
> > static struct evsel *find_evsel_group(struct evlist *perf_evlist,
> > @@ -485,8 +486,8 @@ int __weak arch_get_runtimeparam(void)
> > return 1;
> > }
> >
> > -static int __metricgroup__add_metric(struct strbuf *events,
> > - struct list_head *group_list, struct pmu_event *pe, int runtime)
> > +static int __metricgroup__add_metric(struct list_head *group_list,
> > + struct pmu_event *pe, int runtime)
> > {
> > struct egroup *eg;
> >
> > @@ -499,6 +500,7 @@ static int __metricgroup__add_metric(struct strbuf *events,
> > eg->metric_expr = pe->metric_expr;
> > eg->metric_unit = pe->unit;
> > eg->runtime = runtime;
> > + eg->has_constraint = metricgroup__has_constraint(pe);
> >
> > if (expr__find_other(pe->metric_expr, NULL, &eg->pctx, runtime) < 0) {
> > expr__ctx_clear(&eg->pctx);
> > @@ -506,14 +508,6 @@ static int __metricgroup__add_metric(struct strbuf *events,
> > return -EINVAL;
> > }
> >
> > - if (events->len > 0)
> > - strbuf_addf(events, ",");
> > -
> > - if (metricgroup__has_constraint(pe))
> > - metricgroup__add_metric_non_group(events, &eg->pctx);
> > - else
> > - metricgroup__add_metric_weak_group(events, &eg->pctx);
> > -
> > list_add_tail(&eg->nd, group_list);
> >
> > return 0;
> > @@ -524,6 +518,7 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> > {
> > struct pmu_events_map *map = perf_pmu__find_map(NULL);
> > struct pmu_event *pe;
> > + struct egroup *eg;
> > int i, ret = -EINVAL;
> >
> > if (!map)
> > @@ -542,7 +537,8 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> > pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
> >
> > if (!strstr(pe->metric_expr, "?")) {
> > - ret = __metricgroup__add_metric(events, group_list, pe, 1);
> > + ret = __metricgroup__add_metric(group_list,
> > + pe, 1);
> > } else {
> > int j, count;
> >
> > @@ -553,13 +549,29 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> > * those events to group_list.
> > */
> >
> > - for (j = 0; j < count; j++)
> > - ret = __metricgroup__add_metric(events, group_list, pe, j);
> > + for (j = 0; j < count; j++) {
> > + ret = __metricgroup__add_metric(
> > + group_list, pe, j);
> > + }
> > }
> > if (ret == -ENOMEM)
> > break;
> > }
> > }
> > + if (!ret) {
>
> could you please do instead:
>
> if (ret)
> return ret;
>
> so the code below cuts down one indent level and you
> don't need to split up the lines

Done, broken out as a separate patch in v2:
https://lore.kernel.org/lkml/20200520182011.32236-3-irogers@xxxxxxxxxx/

Thanks,
Ian

> thanks,
> jirka
>
> > + list_for_each_entry(eg, group_list, nd) {
> > + if (events->len > 0)
> > + strbuf_addf(events, ",");
> > +
> > + if (eg->has_constraint) {
> > + metricgroup__add_metric_non_group(events,
> > + &eg->pctx);
> > + } else {
> > + metricgroup__add_metric_weak_group(events,
> > + &eg->pctx);
> > + }
> > + }
> > + }
> > return ret;
> > }
> >
> > --
> > 2.26.2.761.g0e0b3e54be-goog
> >
>