Re: [PATCH v4 3/4] perf-stat: introduce config stat.bpf-counter-events

From: Jiri Olsa
Date: Wed Apr 21 2021 - 06:18:53 EST


On Tue, Apr 20, 2021 at 09:21:32PM +0000, Song Liu wrote:
>
>
> > On Apr 20, 2021, at 10:31 AM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > On Mon, Apr 19, 2021 at 01:36:48PM -0700, Song Liu wrote:
> >
> > SNIP
> >
> >> if (stat_config.initial_delay < 0) {
> >> @@ -784,11 +790,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
> >> if (affinity__setup(&affinity) < 0)
> >> return -1;
> >>
> >> - if (target__has_bpf(&target)) {
> >> - evlist__for_each_entry(evsel_list, counter) {
> >> - if (bpf_counter__load(counter, &target))
> >> - return -1;
> >> - }
> >> + evlist__for_each_entry(evsel_list, counter) {
> >> + if (bpf_counter__load(counter, &target))
> >> + return -1;
> >> + if (!evsel__is_bpf(counter))
> >> + all_counters_use_bpf = false;
> >
> > could be done in bpf_counter__load, check below:
> >
> >> }
> >>
> >> evlist__for_each_cpu (evsel_list, i, cpu) {
> >> diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
> >> index 5de991ab46af9..33b1888103dfa 100644
> >> --- a/tools/perf/util/bpf_counter.c
> >> +++ b/tools/perf/util/bpf_counter.c
> >> @@ -790,7 +790,8 @@ int bpf_counter__load(struct evsel *evsel, struct target *target)
> >> {
> >> if (target->bpf_str)
> >> evsel->bpf_counter_ops = &bpf_program_profiler_ops;
> >> - else if (target->use_bpf)
> >> + else if (target->use_bpf ||
> >> + evsel__match_bpf_counter_events(evsel->name))
> >> evsel->bpf_counter_ops = &bperf_ops;
> >
> > with:
> > else
> > all_counters_use_bpf = false;
> >
> > I was also thinking of oving it to evlist, but it's sat specific,
> > so I think it's good as static.. thanks for changing the implementation
>
> Hmm... then we need to somehow make all_counters_use_bpf visible in
> bpf_counter.c, which won't be very clean. Also, since this is stat
> specific, I guess it is better to keep it inside builtin-stat.c?
> The runtime overhead should be minimal.

ah it's different file :) then it's better as it is, sorry

jirka

>
> Thanks,
> Song
>