[PATCH] perf record: Add --buildid-all option

[Namhyung Kim]

The --buildid-all option is to record build-id of all DSOs in the file.
It might be very costly to postprocess samples to find which DSO hits.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-record.txt |  3 +++
 tools/perf/builtin-record.c              | 26 ++++++++++++++++++++------
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 3a1a32f5479f..fbceb631387c 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -338,6 +338,9 @@ Options passed to clang when compiling BPF scriptlets.
 Specify vmlinux path which has debuginfo.
 (enabled when BPF prologue is on)
 
+--buildid-all::
+Record build-id of all DSOs regardless whether it's actually hit or not.
+
 SEE ALSO
 --------
 linkperf:perf-stat[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index dc4e0adf5c5b..319712a4e02b 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -50,6 +50,7 @@ struct record {
 	int			realtime_prio;
 	bool			no_buildid;
 	bool			no_buildid_cache;
+	bool			buildid_all;
 	unsigned long long	samples;
 };
 
@@ -362,6 +363,13 @@ static int process_buildids(struct record *rec)
 	 */
 	symbol_conf.ignore_vmlinux_buildid = true;
 
+	/*
+	 * If --buildid-all is given, it marks all DSO regardless of hits,
+	 * so no need to process samples.
+	 */
+	if (rec->buildid_all)
+		rec->tool.sample = NULL;
+
 	return perf_session__process_events(session);
 }
 
@@ -756,12 +764,8 @@ out_child:
 
 		if (!rec->no_buildid) {
 			process_buildids(rec);
-			/*
-			 * We take all buildids when the file contains
-			 * AUX area tracing data because we do not decode the
-			 * trace because it would take too long.
-			 */
-			if (rec->opts.full_auxtrace)
+
+			if (rec->buildid_all)
 				dsos__hit_all(rec->session);
 		}
 		perf_session__write_header(rec->session, rec->evlist, fd, true);
@@ -1138,6 +1142,8 @@ struct option __record_options[] = {
 		   "options passed to clang when compiling BPF scriptlets"),
 	OPT_STRING(0, "vmlinux", &symbol_conf.vmlinux_name,
 		   "file", "vmlinux pathname"),
+	OPT_BOOLEAN(0, "buildid-all", &record.buildid_all,
+		    "Record build-id of all DSOs regardless of hits"),
 	OPT_END()
 };
 
@@ -1255,6 +1261,14 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (err)
 		goto out_symbol_exit;
 
+	/*
+	 * We take all buildids when the file contains
+	 * AUX area tracing data because we do not decode the
+	 * trace because it would take too long.
+	 */
+	if (rec->opts.full_auxtrace)
+		rec->buildid_all = true;
+
 	if (record_opts__config(&rec->opts)) {
 		err = -EINVAL;
 		goto out_symbol_exit;
-- 
2.6.4