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

Adrian Hunter
2022-06-10T11:33:53Z

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