From 267db6bff34b47d0762358a18315660e26efbe5c Mon Sep 17 00:00:00 2001 From: James Clark Date: Mon, 24 Apr 2023 14:47:41 +0100 Subject: [PATCH] perf cs-etm: Fix timeless decode mode detection [ 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 Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mathieu Poirier Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon 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 Signed-off-by: Sasha Levin --- 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 16db965..09e240e4 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -2488,26 +2488,29 @@ 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; } static const char * const cs_etm_global_header_fmts[] = { @@ -3051,7 +3054,6 @@ int cs_etm__process_auxtrace_info(union perf_event *event, etm->snapshot_mode = (hdr[CS_ETM_SNAPSHOT] != 0); etm->metadata = metadata; etm->auxtrace_type = auxtrace_info->type; - etm->timeless_decoding = cs_etm__is_timeless_decoding(etm); etm->auxtrace.process_event = cs_etm__process_event; etm->auxtrace.process_auxtrace_event = cs_etm__process_auxtrace_event; @@ -3061,6 +3063,10 @@ int cs_etm__process_auxtrace_info(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; -- 2.7.4