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From:   Song Liu <song@kernel.org>
Date:   Thu, 4 May 2023 19:01:04 -0700
Message-ID: <CAPhsuW5e+2rjnbEsXXXuBO2bUvyx0mHquxb6a0a6MGqXdaodUw@mail.gmail.com>
Subject: Re: [RFC PATCH] perf stat: Separate bperf from bpf_profiler
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Namhyung Kim <namhyung@kernel.org>,
        Song Liu <songliubraving@fb.com>,
        Dmitry Dolgov <9erthalion6@gmail.com>,
        linux-perf-users@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        mingo@redhat.com, jolsa@kernel.org, irogers@google.com
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On Fri, Apr 28, 2023 at 6:44=E2=80=AFPM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Fri, Apr 21, 2023 at 10:56:10PM +0200, Dmitry Dolgov escreveu:
> > > On Wed, Apr 12, 2023 at 08:23:16PM +0200, Dmitrii Dolgov wrote:
> > > It seems that perf stat -b <prog id> doesn't produce any results:
> > >
> > >     $ perf stat -e cycles -b 4 -I 10000 -vvv
> > >     Control descriptor is not initialized
> > >     cycles: 0 0 0
> > >                 time        counts unit      events
> > >     10.007641640    <not supported>      cycles
> > >
> > > Looks like this happens because fentry/fexit progs are getting loaded=
, but the
> > > corresponding perf event is not enabled and not added into the events=
 bpf map.
> > > I think there is some mixing up between two type of bpf support, one =
for bperf
> > > and one for bpf_profiler. Both are identified via evsel__is_bpf, base=
d on which
> > > perf events are enabled, but for the latter (bpf_profiler) a perf eve=
nt is
> > > required. Using evsel__is_bperf to check only bperf produces expected=
 results:
> >
> > Any thoughts on this? I would appreciate clarifications if I'm missing
> > something.
>
> Namhyung, Song, can you please take a look at this?

Sorry for the late response. The fix looks good to me and worked well
in my test.

Reviewed-and-tested-by: Song Liu <song@kernel.org>

I guess we also need:

Fixes: 112cb56164bc2 ("perf stat: Introduce config stat.bpf-counter-events"=
)

Thanks for the fix!
Song