On Wed, Apr 29, 2020 at 10:11:03AM -0300, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <[email protected]>
>
> 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 <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Namhyung Kim <[email protected]>
> Cc: Song Liu <[email protected]>
> Link: http://lore.kernel.org/lkml/[email protected]
> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
> ---
> 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
