Messages in this thread | | | Date | Thu, 14 Apr 2022 08:52:57 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2] perf report: Set PERF_SAMPLE_DATA_SRC bit for Arm SPE event |
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Em Thu, Apr 14, 2022 at 07:01:24PM +0800, Leo Yan escreveu: > On Thu, Apr 14, 2022 at 11:29:48AM +0100, James Clark wrote: > > On 14/04/2022 02:27, Arnaldo Carvalho de Melo wrote: > > > Em Wed, Apr 13, 2022 at 05:23:17PM +0800, Leo Yan escreveu: > > >> Since commit bb30acae4c4d ("perf report: Bail out --mem-mode if mem info > > >> is not available") "perf mem report" and "perf report --mem-mode" > > >> don't report result if the PERF_SAMPLE_DATA_SRC bit is missed in sample > > >> type. > > >> > > >> The commit ffab48705205 ("perf: arm-spe: Fix perf report --mem-mode") > > >> partially fixes the issue. It adds PERF_SAMPLE_DATA_SRC bit for Arm SPE > > >> event, this allows the perf data file generated by kernel v5.18-rc1 or > > >> later version can be reported properly. > > >> > > >> On the other hand, perf tool still fails to be backward compatibility > > >> for a data file recorded by an older version's perf which contains Arm > > >> SPE trace data. This patch is a workaround in reporting phase, when > > >> detects ARM SPE PMU event and without PERF_SAMPLE_DATA_SRC bit, it will > > >> force to set the bit in the sample type and give a warning info. > > >> > > >> Fixes: bb30acae4c4d ("perf report: Bail out --mem-mode if mem info is not available") > > >> Signed-off-by: Leo Yan <leo.yan@linaro.org> > > >> Tested-by: German Gomez <german.gomez@arm.com> > > >> --- > > >> v2: Change event name from "arm_spe_" to "arm_spe"; > > >> Add German's test tag. > > > > > > Tentatively applied, would be great to have James' and Ravi's > > > Acked-by/Reviewed-by, which I'll add before pushing this out if provided > > > in time. > > > > > > - Arnaldo > > > > > >> tools/perf/builtin-report.c | 16 ++++++++++++++++ > > >> 1 file changed, 16 insertions(+) > > >> > > >> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c > > >> index 1ad75c7ba074..acb07a4a9b67 100644 > > >> --- a/tools/perf/builtin-report.c > > >> +++ b/tools/perf/builtin-report.c > > >> @@ -353,6 +353,7 @@ static int report__setup_sample_type(struct report *rep) > > >> struct perf_session *session = rep->session; > > >> u64 sample_type = evlist__combined_sample_type(session->evlist); > > >> bool is_pipe = perf_data__is_pipe(session->data); > > >> + struct evsel *evsel; > > >> > > >> if (session->itrace_synth_opts->callchain || > > >> session->itrace_synth_opts->add_callchain || > > >> @@ -407,6 +408,21 @@ static int report__setup_sample_type(struct report *rep) > > >> } > > >> > > >> if (sort__mode == SORT_MODE__MEMORY) { > > >> + /* > > >> + * FIXUP: prior to kernel 5.18, Arm SPE missed to set > > >> + * PERF_SAMPLE_DATA_SRC bit in sample type. For backward > > >> + * compatibility, set the bit if it's an old perf data file. > > >> + */ > > >> + evlist__for_each_entry(session->evlist, evsel) { > > >> + if (strstr(evsel->name, "arm_spe") && > > >> + !(sample_type & PERF_SAMPLE_DATA_SRC)) { > > >> + ui__warning("PERF_SAMPLE_DATA_SRC bit is not set " > > >> + "for Arm SPE event.\n"); > > > > Looks ok to me. Personally I would remove the warning, otherwise people are going to start > > thinking that they need to do something about it or something bad has happened. > > > > But because we've fixed it up there shouldn't really need to be a warning or any action. > > Understand. The warning is not bad for developers but it might > introduce confusion for users, and if we really want to check the sample > type then we can use 'perf evlist' command, so it's not very useful for > the warning. > > I will remove the warning and resend a new patch.
Waiting then
> > I don't feel too strongly about this though, so I will leave it up to Leo to make the > > final decision: > > > > Reviewed-by: James Clark <james.clark@arm.com> > > Thanks a lot for reviewing. > Leo
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- Arnaldo
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