linux-kernel - Re: [PATCH 2/2] perf stat: fix unexpected delay behaviour

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Message-ID: <CAM9d7cj=Pu2QAONzd2JSVzd_X9DakeV=khcFGD_d-ES5zrx+KQ@mail.gmail.com>
Date:   Tue, 13 Dec 2022 08:40:31 -0800
From:   Namhyung Kim <namhyung@...nel.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     James Clark <james.clark@....com>,
        Adrián Herrera Arcila <adrian.herrera@....com>,
        linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        leo.yan@...aro.org, songliubraving@...com, peterz@...radead.org,
        mingo@...hat.com, mark.rutland@....com,
        alexander.shishkin@...ux.intel.com, jolsa@...nel.org
Subject: Re: [PATCH 2/2] perf stat: fix unexpected delay behaviour

Hi,

On Tue, Dec 13, 2022 at 6:44 AM Arnaldo Carvalho de Melo
<acme@...nel.org> wrote:
>
> Em Mon, Aug 01, 2022 at 09:20:37AM +0100, James Clark escreveu:
> >
> >
> > On 29/07/2022 17:12, Adrián Herrera Arcila wrote:
> > > The described --delay behaviour is to delay the enablement of events, but
> > > not the execution of the command, if one is passed, which is incorrectly
> > > the current behaviour.
> > >
> > > This patch decouples the enablement from the delay, and enables events
> > > before or after launching the workload dependent on the options passed
> > > by the user. This code structure is inspired by that in perf-record, and
> > > tries to be consistent with it.
> > >
> > > Link: https://lore.kernel.org/linux-perf-users/7BFD066E-B0A8-49D4-B635-379328F0CF4C@fb.com
> > > Fixes: d0a0a511493d ("perf stat: Fix forked applications enablement of counters")
> > > Signed-off-by: Adrián Herrera Arcila <adrian.herrera@....com>
> > > ---
> > >  tools/perf/builtin-stat.c | 56 ++++++++++++++++++++++-----------------
> > >  1 file changed, 32 insertions(+), 24 deletions(-)
> >
> > Looks good to me. Fixes the counter delay issue and the code is pretty
> > similar to perf record now. Although I would wait for Leo's or Song's
> > comment as well because they were involved.
>
> I think I didn't notice Leo's ack, it still applies, so I'm doing it
> now.

I think the BPF counters should be enabled/disabled together.

Thanks,
Namhyung