[PATCH 10/11] perf tools: Add debug messages and comments for testing

[Adrian Hunter]

Add debug messages to enable scripts to track aspects of perf record
behaviour. The messages will be consumed after perf record has run,
with the exception of "perf record has started" which is consequently
flushed.

Put comments so developers know which messages are also being used by test
scripts.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 tools/lib/perf/evlist.c     | 2 ++
 tools/perf/builtin-record.c | 8 ++++++++
 tools/perf/util/evsel.c     | 2 ++
 3 files changed, 12 insertions(+)

diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 6b1bafe267a4..80cc810c5097 100644
--- a/tools/lib/perf/evlist.c
+++ b/tools/lib/perf/evlist.c
@@ -486,6 +486,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 			if (ops->idx)
 				ops->idx(evlist, evsel, mp, idx);
 
+			/* Debug message used by test scripts */
 			pr_debug("idx %d: mmapping fd %d\n", idx, *output);
 			if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
 				return -1;
@@ -495,6 +496,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 			if (!idx)
 				perf_evlist__set_mmap_first(evlist, map, overwrite);
 		} else {
+			/* Debug message used by test scripts */
 			pr_debug("idx %d: set output fd %d -> %d\n", idx, fd, *output);
 			if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
 				return -1;
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 02e38f50a138..5b808ac7a281 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2428,10 +2428,14 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
 	record__uniquify_name(rec);
 
+	/* Debug message used by test scripts */
+	pr_debug3("perf record opening and mmapping events\n");
 	if (record__open(rec) != 0) {
 		err = -1;
 		goto out_free_threads;
 	}
+	/* Debug message used by test scripts */
+	pr_debug3("perf record done opening and mmapping events\n");
 	session->header.env.comp_mmap_len = session->evlist->core.mmap_len;
 
 	if (rec->opts.kcore) {
@@ -2574,6 +2578,10 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	if (err)
 		goto out_child;
 
+	/* Debug message used by test scripts */
+	pr_debug3("perf record has started\n");
+	fflush(stderr);
+
 	trigger_ready(&auxtrace_snapshot_trigger);
 	trigger_ready(&switch_output_trigger);
 	perf_hooks__invoke_record_start();
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 5776bfa70f11..a27092339b81 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2089,6 +2089,7 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 
 			test_attr__ready();
 
+			/* Debug message used by test scripts */
 			pr_debug2_peo("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
 				pid, perf_cpu_map__cpu(cpus, idx).cpu, group_fd, evsel->open_flags);
 
@@ -2114,6 +2115,7 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 						fd, group_fd, evsel->open_flags);
 			}
 
+			/* Debug message used by test scripts */
 			pr_debug2_peo(" = %d\n", fd);
 
 			if (evsel->bpf_fd >= 0) {
-- 
2.25.1