Re: [PATCH 1/1] perf evsel: Introduce evsel__name_is() method to check if the evsel name is equal to a given string

From: Arnaldo Carvalho de Melo
Date: Mon Apr 24 2023 - 13:27:49 EST


Em Mon, Apr 24, 2023 at 02:25:27PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Apr 20, 2023 at 05:16:18PM -0400, Liang, Kan escreveu:
> >
> >
> > On 2023-04-20 3:28 p.m., Arnaldo Carvalho de Melo wrote:
> > > Em Thu, Apr 20, 2023 at 04:10:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> > >> Em Thu, Apr 20, 2023 at 03:57:55PM -0300, Arnaldo Carvalho de Melo escreveu:
> > >>> This makes the logic a bit clear by avoiding the !strcmp() pattern and
> > >>> also a way to intercept the pointer if we need to do extra validation on
> > >>> it or to do lazy setting of evsel->name via evsel__name(evsel).
> > >>
> > >> + this, looking if there are others...
> > >
> > > Somehow the first message didn't go thru, so below is the combined
> > > patch, this is an effort to avoid accessing evsel->name directly as the
> > > preferred way to get an evsel name is evsel__name(), so looking for
> > > direct access and providing accessors that avoid that.
> >
> > One more
> >
> > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> > index 2260e27adf44..3a960a3f6962 100644
> > --- a/tools/perf/util/evlist.c
> > +++ b/tools/perf/util/evlist.c
> > @@ -467,7 +467,7 @@ static int evsel__strcmp(struct evsel *pos, char
> > *evsel_name)
> > return 0;
> > if (evsel__is_dummy_event(pos))
> > return 1;
> > - return strcmp(pos->name, evsel_name);
> > + return !evsel__name_is(pos, evsel_name);
> > }
> >
> > static int evlist__is_enabled(struct evlist *evlist)
>
> Added
>
> > >
> > > From e60455d6a4e35ba0c376966443294586a1adc3ec Mon Sep 17 00:00:00 2001
> > > From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > > Date: Thu, 20 Apr 2023 15:54:11 -0300
> > > Subject: [PATCH 1/1] perf evsel: Introduce evsel__name_is() method to check if
> > > the evsel name is equal to a given string
> > >
> > > This makes the logic a bit clear by avoiding the !strcmp() pattern and
> > > also a way to intercept the pointer if we need to do extra validation on
> > > it or to do lazy setting of evsel->name via evsel__name(evsel).
> > >
> > > Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> > > Cc: Ian Rogers <irogers@xxxxxxxxxx>
> > > Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> > > Cc: "Liang, Kan" <kan.liang@xxxxxxxxxxxxxxx>
> > > Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> > > Link: https://lore.kernel.org/lkml/ZEGLM8VehJbS0gP2@xxxxxxxxxx
> > > Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> >
> > With the above one,
> >
> > Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> Added these extra ones and actually made evsel__name_is() use
> evsel__name().
>
> Does your reviewed-by stands after these extra changes?


oops, fix that pos->name leftover:


diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 2260e27adf44c579..a0504316b06fbcba 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -467,7 +467,7 @@ static int evsel__strcmp(struct evsel *pos, char *evsel_name)
return 0;
if (evsel__is_dummy_event(pos))
return 1;
- return strcmp(pos->name, evsel_name);
+ return !evsel__name_is(pos, evsel_name);
}

static int evlist__is_enabled(struct evlist *evlist)
@@ -1706,7 +1706,7 @@ struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str)
evlist__for_each_entry(evlist, evsel) {
if (!evsel->name)
continue;
- if (strcmp(str, evsel->name) == 0)
+ if (evsel__name_is(evsel, str))
return evsel;
}

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 81b854650160c2b0..356c07f03be6bfce 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -823,7 +823,7 @@ const char *evsel__name(struct evsel *evsel)

bool evsel__name_is(struct evsel *evsel, const char *name)
{
- return !strcmp(evsel->name, name);
+ return !strcmp(evsel__name(evsel), name);
}

const char *evsel__group_pmu_name(const struct evsel *evsel)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 31b1cd0935e277ba..650cd8df40412a38 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2893,7 +2893,7 @@ static struct evsel *find_evsel(struct evlist *evlist, char *event_name)
full_name = !!strchr(event_name, ':');
evlist__for_each_entry(evlist, pos) {
/* case 2 */
- if (full_name && !strcmp(pos->name, event_name))
+ if (full_name && evsel__name_is(pos, event_name))
return pos;
/* case 3 */
if (!full_name && strstr(pos->name, event_name)) {