> On Apr 3, 2019, at 8:15 AM, Arnaldo Carvalho de Melo <arnaldo.m...@gmail.com>
> wrote:
>
> Em Wed, Apr 03, 2019 at 11:53:53AM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Wed, Apr 03, 2019 at 04:37:38PM +0200, Jiri Olsa escreveu:
>>> hi,
>>> perf script --call-trace stop working for me recently,
>>> and displays only user space functions
>>>
>>> I bisected that to:
>>> 7b612e291a5a perf tools: Synthesize PERF_RECORD_* for loaded BPF programs
>>>
>>> data from following comands will display user space functions only:
>>> # perf-with-kcore record pt -e intel_pt// -- ls
>>> # perf-with-kcore script pt --call-trace
>>>
>>> when I disable the bpf synthesizing (patch below), kernel functions are back
>>>
>>> I guess the new events mess up with intel_pt decoder somehow
>>
>> I.e. I'm adding the patch below to my perf/urgent branch.
>
> Song, that is what I have, can I have your Acked-by and please consider
> taking a look at the bug Jiri reported,
>
> Thanks,
>
> - Arnaldo
Current logic with --no-bpf-event is to generate PERF_RECORD_KSYMBOL, but not
PERF_RECORD_BPF_EVENT:
https://elixir.bootlin.com/linux/v5.1-rc3/source/tools/perf/util/bpf-event.c#L254
I will look into the intel_pt problem.
In the meanwhile, let's fix it for now.
Acked-by: Song Liu <songliubrav...@fb.com>
Thanks,
Song
> commit 011318ccc2024ba03e96c32a06f74ca5d6ab5503
> Author: Arnaldo Carvalho de Melo <a...@redhat.com>
> Date: Wed Apr 3 12:05:15 2019 -0300
>
> perf record: Do not synthesize BPF records when --no-bpf-event is used
>
> By default we synthesize and ask the kernel for BPF events, having a
> --no-bpf-event option to disable that, which can be useful, for
> instance, if there are still bugs in that code, which seems to be the
> case as reported by Jiri Olsa in:
>
> "[BUG] perf: intel_pt won't display kernel function"
> https://lore.kernel.org/lkml/20190403143738.GB32001@krava
>
> So add the check for record_opts.no_bpf_event when considering
> synthesizing BPF events for pre-existing BPF programs in 'perf record'.
>
> The reported bug needs further analysis and is a separate matter.
>
> Cc: Adrian Hunter <adrian.hun...@intel.com>
> Cc: Alexei Starovoitov <a...@kernel.org>
> Cc: Andrii Nakryiko <andrii.nakry...@gmail.com>
> Cc: Daniel Borkmann <dan...@iogearbox.net>
> Cc: Jiri Olsa <jo...@kernel.org>
> Cc: Martin KaFai Lau <ka...@fb.com>
> Cc: Namhyung Kim <namhy...@kernel.org>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Song Liu <songliubrav...@fb.com>
> Cc: Yonghong Song <y...@fb.com>
> Fixes: 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF
> programs")
> Link: https://lore.kernel.org/lkml/20190403145353.ge32...@kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 4e2d953d4bc5..17d772f192ad 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1114,10 +1114,11 @@ static int record__synthesize(struct record *rec,
> bool tail)
> return err;
> }
>
> - err = perf_event__synthesize_bpf_events(session,
> process_synthesized_event,
> - machine, opts);
> - if (err < 0)
> - pr_warning("Couldn't synthesize bpf events.\n");
> + if (!opts->no_bpf_event) {
> + err = perf_event__synthesize_bpf_events(session,
> process_synthesized_event, machine, opts);
> + if (err < 0)
> + pr_warning("Couldn't synthesize bpf events.\n");
> + }
>
> err = __machine__synthesize_threads(machine, tool, &opts->target,
> rec->evlist->threads,
> process_synthesized_event,
> opts->sample_address,
