From: James Clark james.clark@arm.com
[ Upstream commit 449067f3fc9f340da54e383738286881e6634d0b ]
In this context, timeless refers to the trace data rather than the perf event data. But when detecting whether there are timestamps in the trace data or not, the presence of a timestamp flag on any perf event is used.
Since commit f42c0ce573df ("perf record: Always get text_poke events with --kcore option") timestamps were added to a tracking event when --kcore is used which breaks this detection mechanism. Fix it by detecting if trace timestamps exist by looking at the ETM config flags. This would have always been a more accurate way of doing it anyway.
This fixes the following error message when using --kcore with Coresight:
$ perf record --kcore -e cs_etm// --per-thread $ perf report The perf.data/data data has no samples!
Fixes: f42c0ce573df79d1 ("perf record: Always get text_poke events with --kcore option") Reported-by: Yang Shi shy828301@gmail.com Signed-off-by: James Clark james.clark@arm.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ian Rogers irogers@google.com Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: John Garry john.g.garry@oracle.com Cc: Leo Yan leo.yan@linaro.org Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Suzuki Poulouse suzuki.poulose@arm.com Cc: Will Deacon will@kernel.org Cc: coresight@lists.linaro.org Cc: denik@google.com Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/lkml/CAHbLzkrJQTrYBtPkf=jf3OpQ-yBcJe7XkvQstX9j2frz4W... Link: https://lore.kernel.org/r/20230424134748.228137-2-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/cs-etm.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index f65bac5ddbdb6..e43bc9eea3087 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -2517,26 +2517,29 @@ static int cs_etm__process_auxtrace_event(struct perf_session *session, return 0; }
-static bool cs_etm__is_timeless_decoding(struct cs_etm_auxtrace *etm) +static int cs_etm__setup_timeless_decoding(struct cs_etm_auxtrace *etm) { struct evsel *evsel; struct evlist *evlist = etm->session->evlist; - bool timeless_decoding = true;
/* Override timeless mode with user input from --itrace=Z */ - if (etm->synth_opts.timeless_decoding) - return true; + if (etm->synth_opts.timeless_decoding) { + etm->timeless_decoding = true; + return 0; + }
/* - * Circle through the list of event and complain if we find one - * with the time bit set. + * Find the cs_etm evsel and look at what its timestamp setting was */ - evlist__for_each_entry(evlist, evsel) { - if ((evsel->core.attr.sample_type & PERF_SAMPLE_TIME)) - timeless_decoding = false; - } + evlist__for_each_entry(evlist, evsel) + if (cs_etm__evsel_is_auxtrace(etm->session, evsel)) { + etm->timeless_decoding = + !(evsel->core.attr.config & BIT(ETM_OPT_TS)); + return 0; + }
- return timeless_decoding; + pr_err("CS ETM: Couldn't find ETM evsel\n"); + return -EINVAL; }
/* @@ -2943,7 +2946,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, etm->snapshot_mode = (ptr[CS_ETM_SNAPSHOT] != 0); etm->metadata = metadata; etm->auxtrace_type = auxtrace_info->type; - etm->timeless_decoding = cs_etm__is_timeless_decoding(etm);
/* Use virtual timestamps if all ETMs report ts_source = 1 */ etm->has_virtual_ts = cs_etm__has_virtual_ts(metadata, num_cpu); @@ -2960,6 +2962,10 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event, etm->auxtrace.evsel_is_auxtrace = cs_etm__evsel_is_auxtrace; session->auxtrace = &etm->auxtrace;
+ err = cs_etm__setup_timeless_decoding(etm); + if (err) + return err; + etm->unknown_thread = thread__new(999999999, 999999999); if (!etm->unknown_thread) { err = -ENOMEM;