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perf cs-etm: Fix timeless decode mode detection

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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 f42c0ce573 ("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: f42c0ce573 ("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-yBcJe7XkvQstX9j2frz4WF-SQ@mail.gmail.com/
Link: https://lore.kernel.org/r/20230424134748.228137-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
James Clark 2023-04-24 14:47:41 +01:00 committed by Arnaldo Carvalho de Melo
parent ce1d3bc273
commit 449067f3fc
1 changed files with 20 additions and 14 deletions
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34
tools/perf/util/cs-etm.c
View file

@ -2684,26 +2684,29 @@ 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;
/*
* Circle through the list of event and complain if we find one
* with the time bit set.
*/
evlist__for_each_entry(evlist, evsel) {
if ((evsel->core.attr.sample_type & PERF_SAMPLE_TIME))
timeless_decoding = false;
if (etm->synth_opts.timeless_decoding) {
etm->timeless_decoding = true;
return 0;
}
return timeless_decoding;
/*
* Find the cs_etm evsel and look at what its timestamp setting was
*/
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;
}
pr_err("CS ETM: Couldn't find ETM evsel\n");
return -EINVAL;
}
/*
@ -3155,7 +3158,6 @@ 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);
@ -3172,6 +3174,10 @@ 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;