Messages in this thread Patch in this message | | | From | Song Liu <> | Subject | Re: [BUG] perf: intel_pt won't display kernel function | Date | Wed, 3 Apr 2019 18:59:51 +0000 |
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> On Apr 3, 2019, at 11:55 AM, Song Liu <songliubraving@fb.com> wrote: > > > >> On Apr 3, 2019, at 11:50 AM, Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> wrote: >> >> Em Wed, Apr 03, 2019 at 04:27:56PM +0000, Song Liu escreveu: >>> >>> >>>> On Apr 3, 2019, at 8:15 AM, Arnaldo Carvalho de Melo <arnaldo.melo@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: >> >> I see... The opts is done later, after querying the kernel for existing >> BPF programs so that at least the KSYMBOL ones can be generated. So I'll >> keep it as is, no need for this patch. >> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__elixir.bootlin.com_linux_v5.1-2Drc3_source_tools_perf_util_bpf-2Devent.c-23L254&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=dR8692q0_uaizy0jkrBJQM5k2hfm4CiFxYT8KaysFrg&m=8ITYgIrqFBIy1uQFQPHrsX5kBX5RlmhwcknKYJa2eGs&s=MdB2zA9JstwC93qKEonsfTQeQYiw-yeOLbPxm3QMRo8&e= >>> >>> I will look into the intel_pt problem. >> >> Ok. >> >>> In the meanwhile, let's fix it for now. >> >> I'll wait a bit. > > I guess something like this might be a better fix? (Sorry for missing > commit message): > > diff --git i/tools/perf/util/map.c w/tools/perf/util/map.c > index e32628cd20a7..741430a35dca 100644 > --- i/tools/perf/util/map.c > +++ w/tools/perf/util/map.c > @@ -261,6 +261,12 @@ bool __map__is_extra_kernel_map(const struct map *map) > return kmap && kmap->name[0]; > } > > +bool __map__is_bpf_prog(const struct map *map) > +{ > + const char *name = map->dso->short_name; > + return name && (strstr(name, "bpf_prog_") == name); > +} > + > bool map__has_symbols(const struct map *map) > { > return dso__has_symbols(map->dso); > diff --git i/tools/perf/util/map.h w/tools/perf/util/map.h > index 0e20749f2c55..01079f1f4375 100644 > --- i/tools/perf/util/map.h > +++ w/tools/perf/util/map.h > @@ -159,10 +159,12 @@ int map__set_kallsyms_ref_reloc_sym(struct map *map, const char *symbol_name, > > bool __map__is_kernel(const struct map *map); > bool __map__is_extra_kernel_map(const struct map *map); > +bool __map__is_bpf_prog(const struct map *map); > > static inline bool __map__is_kmodule(const struct map *map) > { > - return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map); > + return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map) && > + !__map__is_bpf_prog(map); > } > > bool map__has_symbols(const struct map *map); > > Thanks, > Song
Actually, it should be something like this:
diff --git i/tools/perf/util/map.c w/tools/perf/util/map.c index e32628cd20a7..31cd23612529 100644 --- i/tools/perf/util/map.c +++ w/tools/perf/util/map.c @@ -261,6 +261,11 @@ bool __map__is_extra_kernel_map(const struct map *map) return kmap && kmap->name[0]; }
+bool __map__is_bpf_prog(const struct map *map) +{ + return map->dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO; +} + bool map__has_symbols(const struct map *map) { return dso__has_symbols(map->dso); diff --git i/tools/perf/util/map.h w/tools/perf/util/map.h index 0e20749f2c55..01079f1f4375 100644 --- i/tools/perf/util/map.h +++ w/tools/perf/util/map.h @@ -159,10 +159,12 @@ int map__set_kallsyms_ref_reloc_sym(struct map *map, const char *symbol_name,
bool __map__is_kernel(const struct map *map); bool __map__is_extra_kernel_map(const struct map *map); +bool __map__is_bpf_prog(const struct map *map);
static inline bool __map__is_kmodule(const struct map *map) { - return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map); + return !__map__is_kernel(map) && !__map__is_extra_kernel_map(map) && + !__map__is_bpf_prog(map); }
bool map__has_symbols(const struct map *map);
> >> >>> Acked-by: Song Liu <songliubraving@fb.com> >>> >>> Thanks, >>> Song >>> >>> >>>> commit 011318ccc2024ba03e96c32a06f74ca5d6ab5503 >>>> Author: Arnaldo Carvalho de Melo <acme@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.hunter@intel.com> >>>> Cc: Alexei Starovoitov <ast@kernel.org> >>>> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> >>>> Cc: Daniel Borkmann <daniel@iogearbox.net> >>>> Cc: Jiri Olsa <jolsa@kernel.org> >>>> Cc: Martin KaFai Lau <kafai@fb.com> >>>> Cc: Namhyung Kim <namhyung@kernel.org> >>>> Cc: Peter Zijlstra <peterz@infradead.org> >>>> Cc: Song Liu <songliubraving@fb.com> >>>> Cc: Yonghong Song <yhs@fb.com> >>>> Fixes: 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs") >>>> Link: https://lore.kernel.org/lkml/20190403145353.GE32553@kernel.org >>>> Signed-off-by: Arnaldo Carvalho de Melo <acme@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, >> >> -- >> >> - Arnaldo
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