[PATCH v3 5/5] perf evlist: Add --trace-fields option to show trace fields

Namhyung Kim
2016-01-06T00:56:05Z

To use dynamic sort keys, it might be good to add an option to see the
list of field names.

$ perf evlist -i perf.data.sched
sched:sched_switch
sched:sched_stat_wait
sched:sched_stat_sleep
sched:sched_stat_iowait
sched:sched_stat_runtime
sched:sched_process_fork
sched:sched_wakeup
sched:sched_wakeup_new
sched:sched_migrate_task
# Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events

$ perf evlist -i perf.data.sched --trace-fields
sched:sched_switch: trace_fields=prev_comm,prev_pid,prev_prio,prev_state,next_comm,next_pid,next_prio
sched:sched_stat_wait: trace_fields=comm,pid,delay
sched:sched_stat_sleep: trace_fields=comm,pid,delay
sched:sched_stat_iowait: trace_fields=comm,pid,delay
sched:sched_stat_runtime: trace_fields=comm,pid,runtime,vruntime
sched:sched_process_fork: trace_fields=parent_comm,parent_pid,child_comm,child_pid
sched:sched_wakeup: trace_fields=comm,pid,prio,success,target_cpu
sched:sched_wakeup_new: trace_fields=comm,pid,prio,success,target_cpu
sched:sched_migrate_task: trace_fields=comm,pid,prio,orig_cpu,dest_cpu

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/Documentation/perf-evlist.txt | 3 +++
tools/perf/builtin-evlist.c | 11 ++++++++++-
tools/perf/util/evsel.c | 23 +++++++++++++++++++++++
tools/perf/util/evsel.h | 1 +
4 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-evlist.txt b/tools/perf/Documentation/perf-evlist.txt
index 1ceb3700ffbb..6f7200fb85cf 100644
--- a/tools/perf/Documentation/perf-evlist.txt
+++ b/tools/perf/Documentation/perf-evlist.txt
@@ -32,6 +32,9 @@ OPTIONS
--group::
Show event group information.

+--trace-fields::
+ Show tracepoint field names.
+
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-list[1],
diff --git a/tools/perf/builtin-evlist.c b/tools/perf/builtin-evlist.c
index 08a7d36a2cf8..8a31f511e1a0 100644
--- a/tools/perf/builtin-evlist.c
+++ b/tools/perf/builtin-evlist.c
@@ -26,14 +26,22 @@ static int __cmd_evlist(const char *file_name, struct perf_attr_details *details
.mode = PERF_DATA_MODE_READ,
.force = details->force,
};
+ bool has_tracepoint = false;

session = perf_session__new(&file, 0, NULL);
if (session == NULL)
return -1;

- evlist__for_each(session->evlist, pos)
+ evlist__for_each(session->evlist, pos) {
perf_evsel__fprintf(pos, details, stdout);

+ if (pos->attr.type == PERF_TYPE_TRACEPOINT)
+ has_tracepoint = true;
+ }
+
+ if (has_tracepoint && !details->trace_fields)
+ printf("# Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events\n");
+
perf_session__delete(session);
return 0;
}
@@ -49,6 +57,7 @@ int cmd_evlist(int argc, const char **argv, const char *prefix __maybe_unused)
OPT_BOOLEAN('g', "group", &details.event_group,
"Show event group information"),
OPT_BOOLEAN('f', "force", &details.force, "don't complain, do it"),
+ OPT_BOOLEAN(0, "trace-fields", &details.trace_fields, "Show tracepoint fields"),
OPT_END()
};
const char * const evlist_usage[] = {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 544e4400de13..b7822c98fcca 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2298,6 +2298,29 @@ int perf_evsel__fprintf(struct perf_evsel *evsel,
printed += comma_fprintf(fp, &first, " %s=%" PRIu64,
term, (u64)evsel->attr.sample_freq);
}
+
+ if (details->trace_fields) {
+ struct format_field *field;
+
+ if (evsel->attr.type != PERF_TYPE_TRACEPOINT) {
+ printed += comma_fprintf(fp, &first, " (not a tracepoint)");
+ goto out;
+ }
+
+ field = evsel->tp_format->format.fields;
+ if (field == NULL) {
+ printed += comma_fprintf(fp, &first, " (no trace field)");
+ goto out;
+ }
+
+ printed += comma_fprintf(fp, &first, " trace_fields=%s", field->name);
+
+ field = field->next;
+ while (field) {
+ printed += comma_fprintf(fp, &first, "%s", field->name);
+ field = field->next;
+ }
+ }
out:
fputc('\n', fp);
return ++printed;
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 5ded1fc0341e..8e75434bd01c 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -369,6 +369,7 @@ struct perf_attr_details {
bool verbose;
bool event_group;
bool force;
+ bool trace_fields;
};

int perf_evsel__fprintf(struct perf_evsel *evsel,
--
2.6.4