[PATCH V2 08/12] perf intel-pt: Use itrace debug log flags to suppress some messages

From: Adrian Hunter
Date: Fri Jul 10 2020 - 11:18:17 EST


The "d" option may be followed by flags which affect what debug messages
will or will not be logged. Each flag must be preceded by either '+' or
'-'. The flags support by Intel PT are:
-a Suppress logging of perf events

Suppressing perf events is useful for decreasing the size of the log.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/Documentation/perf-intel-pt.txt | 5 ++++-
tools/perf/util/intel-pt.c | 17 ++++++++++-------
2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt
index 20ac592a2641..d22dead7bbe0 100644
--- a/tools/perf/Documentation/perf-intel-pt.txt
+++ b/tools/perf/Documentation/perf-intel-pt.txt
@@ -882,7 +882,10 @@ For example, for errors but not overflow or data lost errors:

The "d" option will cause the creation of a file "intel_pt.log" containing all
decoded packets and instructions. Note that this option slows down the decoder
-and that the resulting file may be very large.
+and that the resulting file may be very large. The "d" option may be followed
+by flags which affect what debug messages will or will not be logged. Each flag
+must be preceded by either '+' or '-'. The flags support by Intel PT are:
+ -a Suppress logging of perf events

In addition, the period of the "instructions" event can be specified. e.g.

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index a1cb6a284a2b..34caf24998dd 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -249,6 +249,11 @@ static void intel_pt_dump_sample(struct perf_session *session,
intel_pt_dump(pt, sample->aux_sample.data, sample->aux_sample.size);
}

+static bool intel_pt_log_events(struct intel_pt *pt)
+{
+ return !(pt->synth_opts.log_minus_flags & AUXTRACE_LOG_FLG_ALL_PERF_EVTS);
+}
+
static int intel_pt_do_fix_overlap(struct intel_pt *pt, struct auxtrace_buffer *a,
struct auxtrace_buffer *b)
{
@@ -2585,10 +2590,6 @@ static int intel_pt_context_switch(struct intel_pt *pt, union perf_event *event,
return -EINVAL;
}

- intel_pt_log("context_switch: cpu %d pid %d tid %d time %"PRIu64" tsc %#"PRIx64"\n",
- cpu, pid, tid, sample->time, perf_time_to_tsc(sample->time,
- &pt->tc));
-
ret = intel_pt_sync_switch(pt, cpu, tid, sample->time);
if (ret <= 0)
return ret;
@@ -2745,9 +2746,11 @@ static int intel_pt_process_event(struct perf_session *session,
if (!err && event->header.type == PERF_RECORD_TEXT_POKE)
err = intel_pt_text_poke(pt, event);

- intel_pt_log("event %u: cpu %d time %"PRIu64" tsc %#"PRIx64" ",
- event->header.type, sample->cpu, sample->time, timestamp);
- intel_pt_log_event(event);
+ if (intel_pt_enable_logging && intel_pt_log_events(pt)) {
+ intel_pt_log("event %u: cpu %d time %"PRIu64" tsc %#"PRIx64" ",
+ event->header.type, sample->cpu, sample->time, timestamp);
+ intel_pt_log_event(event);
+ }

return err;
}
--
2.17.1