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References: <20230725061649.34937-1-adityag@linux.ibm.com> <ZMPWk5K63tadmDlU@kernel.org>
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From:   Ian Rogers <irogers@google.com>
Date:   Fri, 28 Jul 2023 09:01:11 -0700
Message-ID: <CAP-5=fW1zkpJ4zr4ngz=6bZQuE6hOHo4AtXwUsVJK9oiDSc_mg@mail.gmail.com>
Subject: Re: [PATCH 1/1] perf tests task_analyzer: Check perf build options
 for libtraceevent support
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Aditya Gupta <adityag@linux.ibm.com>, jolsa@kernel.org,
        namhyung@kernel.org, linux-perf-users@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com,
        atrajeev@linux.vnet.ibm.com, kjain@linux.ibm.com,
        disgoel@linux.vnet.ibm.com, linux-kernel@vger.kernel.org
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On Fri, Jul 28, 2023 at 7:54=E2=80=AFAM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Tue, Jul 25, 2023 at 11:46:49AM +0530, Aditya Gupta escreveu:
> > Currently we depend on output of 'perf record -e "sched:sched_switch"',=
 to
> > check whether perf was built with libtraceevent support.
> >
> > Instead, a more straightforward approach can be to check the build opti=
ons,
> > using 'perf version --build-options', to check for libtraceevent suppor=
t.
> >
> > When perf is compiled WITHOUT libtraceevent ('make NO_LIBTRACEEVENT=3D1=
'),
> > 'perf version --build-options' outputs (output trimmed):
> >
> >        ...
> >          libtraceevent: [ OFF ]  # HAVE_LIBTRACEEVENT
> >        ...
> >
> > While, when perf is compiled WITH libtraceevent,
> >
> > 'perf version --build-options' outputs:
> >
> > ...
> >          libtraceevent: [ on ]  # HAVE_LIBTRACEEVENT
> >        ...
> >
> > Suggested-by: Ian Rogers <irogers@google.com>
> > Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
> > ---
> >
> >  tools/perf/tests/shell/test_task_analyzer.sh | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/tests/shell/test_task_analyzer.sh b/tools/perf/=
tests/shell/test_task_analyzer.sh
> > index 0095abbe20ca..a28d784987b4 100755
> > --- a/tools/perf/tests/shell/test_task_analyzer.sh
> > +++ b/tools/perf/tests/shell/test_task_analyzer.sh
> > @@ -52,7 +52,7 @@ find_str_or_fail() {
> >
> >  # check if perf is compiled with libtraceevent support
> >  skip_no_probe_record_support() {
> > -     perf record -e "sched:sched_switch" -a -- sleep 1 2>&1 | grep "li=
btraceevent is necessary for tracepoint support" && return 2
> > +     perf version --build-options | grep HAVE_LIBTRACEEVENT | grep -q =
OFF && return 2
> >       return 0
>
> I'll apply this, but please consider adding a:
>
>         perf build --has libtraceevent

That's a nice idea. You mean add a script like perf-archive.sh?
Perhaps this flag should be supported by perf version instead.

Thanks,
Ian

> subcommand to have that query made more compact and to avoid the two
> extra grep.
>
> BTW, I'll change that to:
>
> [acme@quaco perf-tools-next]$ perf version --build-options | grep " on .*=
 HAVE_LIBTRACEEVENT"
>          libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
> [acme@quaco perf-tools-next]$
>
> replacing "on" with OFF, so that we have just one grep.
>
> Thanks,
>
> - Arnaldo
>
> >  }
> >
> > --
> > 2.41.0
> >
>
> --
>
> - Arnaldo