Messages in this thread | | | Date | Fri, 1 May 2020 13:25:52 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 5/8] perf evlist: Allow reusing the side band thread for more purposes |
| |
On Wed, Apr 29, 2020 at 10:11:03AM -0300, Arnaldo Carvalho de Melo wrote: > From: Arnaldo Carvalho de Melo <acme@redhat.com> > > I.e. so far we had just one event in that side band thread, a dummy one > with attr.bpf_event set, so that 'perf record' can go ahead and ask the > kernel for further information about BPF programs being loaded. > > Allow for more than one event to be there, so that we can use it as > well for the upcoming --switch-output-event feature. > > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Song Liu <songliubraving@fb.com> > Link: http://lore.kernel.org/lkml/20200427211935.25789-7-acme@kernel.org > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > --- > tools/perf/util/evlist.c | 22 ++++++++++++++++++++++ > tools/perf/util/evlist.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index 1d0d36da223b..849058766757 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -1777,6 +1777,19 @@ static void *perf_evlist__poll_thread(void *arg) > return NULL; > } > > +void evlist__set_cb(struct evlist *evlist, perf_evsel__sb_cb_t cb, void *data) > +{ > + struct evsel *evsel; > + > + evlist__for_each_entry(evlist, evsel) { > + evsel->core.attr.sample_id_all = 1; > + evsel->core.attr.watermark = 1; > + evsel->core.attr.wakeup_watermark = 1; > + evsel->side_band.cb = cb; > + evsel->side_band.data = data; > + } > +} > + > int perf_evlist__start_sb_thread(struct evlist *evlist, > struct target *target) > { > @@ -1788,6 +1801,15 @@ int perf_evlist__start_sb_thread(struct evlist *evlist, > if (perf_evlist__create_maps(evlist, target)) > goto out_delete_evlist; > > + if (evlist->core.nr_entries > 1) { > + bool can_sample_identifier = perf_can_sample_identifier();
I just found this breaks python, because perf_can_sample_identifier is defined in util/record.c
19: 'import perf' in python : --- start --- test child forked, pid 1808205 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: python/perf.so: undefined symbol: perf_can_sample_identifier test child finished with -1 ---- end ---- 'import perf' in python: FAILED!
jirka
| |