[PATCH 2/5] perf record: Always record id index

[Adrian Hunter <adrian.hunter@intel.com>]

In preparation for recording sideband events in a virtual machine guest so
that they can be injected into a host perf.data file.

Adjust the logic so that if there are IDs then the id index is recorded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/builtin-record.c        | 12 +++++-------
 tools/perf/util/synthetic-events.c |  7 +++++--
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3959a1b86afb..00c2a6cdf1be 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1834,13 +1834,11 @@ static int record__synthesize(struct record *rec, bool tail)
 		goto out;
 
 	/* Synthesize id_index before auxtrace_info */
-	if (rec->opts.auxtrace_sample_mode || rec->opts.full_auxtrace) {
-		err = perf_event__synthesize_id_index(tool,
-						      process_synthesized_event,
-						      session->evlist, machine);
-		if (err)
-			goto out;
-	}
+	err = perf_event__synthesize_id_index(tool,
+					      process_synthesized_event,
+					      session->evlist, machine);
+	if (err)
+		goto out;
 
 	if (rec->opts.full_auxtrace) {
 		err = perf_event__synthesize_auxtrace_info(rec->itr, tool,
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 27acdc5e5723..d75074486a55 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -1719,14 +1719,17 @@ int perf_event__synthesize_id_index(struct perf_tool *tool, perf_event__handler_
 	size_t nr = 0, i = 0, sz, max_nr, n;
 	int err;
 
-	pr_debug2("Synthesizing id index\n");
-
 	max_nr = (UINT16_MAX - sizeof(struct perf_record_id_index)) /
 		 sizeof(struct id_index_entry);
 
 	evlist__for_each_entry(evlist, evsel)
 		nr += evsel->core.ids;
 
+	if (!nr)
+		return 0;
+
+	pr_debug2("Synthesizing id index\n");
+
 	n = nr > max_nr ? max_nr : nr;
 	sz = sizeof(struct perf_record_id_index) + n * sizeof(struct id_index_entry);
 	ev = zalloc(sz);
-- 
2.25.1