Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 2 Jun 2020 10:25:35 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Jiri Olsa <jolsa@redhat.com>
Cc:     Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Jin Yao <yao.jin@linux.intel.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Michael Petlan <mpetlan@redhat.com>,
        Stephane Eranian <eranian@google.com>,
        Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCHv2] perf stat: Ensure group is defined on top of the same
 cpu mask
Message-ID: <20200602132535.GN31795@kernel.org>
References: <20200531162206.911168-1-jolsa@kernel.org>
 <CAP-5=fUk97P-ECojBya1CRE4SQoX2erNgFujEJFvSgOk6e6pdQ@mail.gmail.com>
 <20200601082027.GF881900@krava>
 <CAP-5=fWLp8qyVjwVuQCTEoz=SY5FFtEEZyH5=L-5cAEeN4_5uw@mail.gmail.com>
 <CAM9d7cgw+h9xC08hEErnQnqZjfN1bJWu8psGsUVicWoXWSWcLQ@mail.gmail.com>
 <20200602081551.GC1112120@krava>
 <CAM9d7cgZYjCkrFtpcKr=QHrLY6PkOx6CODBiH8fmoFqEcBXKeQ@mail.gmail.com>
 <20200602121017.GF1112120@krava>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200602121017.GF1112120@krava>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Em Tue, Jun 02, 2020 at 02:10:17PM +0200, Jiri Olsa escreveu:
> On Tue, Jun 02, 2020 at 08:50:17PM +0900, Namhyung Kim wrote:
> > Hi Jiri,
> > 
> > On Tue, Jun 2, 2020 at 5:16 PM Jiri Olsa <jolsa@redhat.com> wrote:
> > >
> > > On Tue, Jun 02, 2020 at 11:47:19AM +0900, Namhyung Kim wrote:
> > > > On Tue, Jun 2, 2020 at 1:21 AM Ian Rogers <irogers@google.com> wrote:
> > > > >
> > > > > On Mon, Jun 1, 2020 at 1:20 AM Jiri Olsa <jolsa@redhat.com> wrote:
> > > > > >
> > > > > > Jin Yao reported the issue (and posted first versions of this change)
> > > > > > with groups being defined over events with different cpu mask.
> > > > > >
> > > > > > This causes assert aborts in get_group_fd, like:
> > > > > >
> > > > > >   # perf stat -M "C2_Pkg_Residency" -a -- sleep 1
> > > > > >   perf: util/evsel.c:1464: get_group_fd: Assertion `!(fd == -1)' failed.
> > > > > >   Aborted
> > > > > >
> > > > > > All the events in the group have to be defined over the same
> > > > > > cpus so the group_fd can be found for every leader/member pair.
> > > > > >
> > > > > > Adding check to ensure this condition is met and removing the
> > > > > > group (with warning) if we detect mixed cpus, like:
> > > > > >
> > > > > >   $ sudo perf stat -e '{power/energy-cores/,cycles},{instructions,power/energy-cores/}'
> > > > > >   WARNING: event cpu maps do not match, disabling group:
> > > > > >     anon group { power/energy-cores/, cycles }
> > > > > >     anon group { instructions, power/energy-cores/ }
> > > > > >
> > > > > > Ian asked also for cpu maps details, it's displayed in verbose mode:
> > > > > >
> > > > > >   $ sudo perf stat -e '{cycles,power/energy-cores/}' -v
> > > > > >   WARNING: group events cpu maps do not match, disabling group:
> > > > > >     anon group { power/energy-cores/, cycles }
> > > > > >        power/energy-cores/: 0
> > > > > >        cycles: 0-7
> > > > > >     anon group { instructions, power/energy-cores/ }
> > > > > >        instructions: 0-7
> > > > > >        power/energy-cores/: 0
> > > > >
> > > > > This is great! A nit, would 'grouped events cpus do not match' read
> > > > > better? I think the cpu map is more of an internal naming convention.
> > > > Allowed cpus?
> > >
> > > hum, what you mean?
> > 
> > I mean that we can use 'allowed cpus' rather then 'cpu map' in the message.
> > Something like this?
> > 
> >   allowed cpus for events in a group do not match, disabling group:
> 
> hm, I like more the one Ian suggested.. anyway, leaving this to Arnaldo,
> he can change that before committing ;-)

I think its ok as-is, Ian, can I have your acked-by?

- Arnaldo