[PATCH RFC 13/21] perf evlist: Add evlist__add_system_wide_dummy()

Adrian Hunter
2022-04-22T16:26:03Z

Add evlist__add_system_wide_dummy() to enable creating a system-wide dummy
event that sets up the system-wide maps before map propagation.

For convenience, add evlist__add_aux_dummy() so that the logic can be used
whether or not the event needs to be system-wide.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/evlist.c | 40 ++++++++++++++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 5 +++++
2 files changed, 45 insertions(+)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 78c47cbafbc2..58ea562ddbd2 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -264,6 +264,46 @@ int evlist__add_dummy(struct evlist *evlist)
return 0;
}

+static void evlist__add_system_wide(struct evlist *evlist, struct evsel *evsel)
+{
+ evsel->core.system_wide = true;
+
+ /* All CPUs */
+ perf_cpu_map__put(evsel->core.own_cpus);
+ evsel->core.own_cpus = perf_cpu_map__new(NULL);
+ perf_cpu_map__put(evsel->core.cpus);
+ evsel->core.cpus = perf_cpu_map__get(evsel->core.own_cpus);
+
+ /* No threads */
+ perf_thread_map__put(evsel->core.threads);
+ evsel->core.threads = perf_thread_map__new_dummy();
+
+ evlist__add(evlist, evsel);
+}
+
+struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide)
+{
+ struct evsel *evsel = evlist__dummy_event(evlist);
+
+ if (!evsel)
+ return NULL;
+
+ evsel->core.attr.exclude_kernel = 1;
+ evsel->core.attr.exclude_guest = 1;
+ evsel->core.attr.exclude_hv = 1;
+ evsel->core.attr.freq = 0;
+ evsel->core.attr.sample_period = 1;
+ evsel->no_aux_samples = true;
+ evsel->name = strdup("dummy:u");
+
+ if (system_wide)
+ evlist__add_system_wide(evlist, evsel);
+ else
+ evlist__add(evlist, evsel);
+
+ return evsel;
+}
+
static int evlist__add_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
{
struct evsel *evsel, *n;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 4062f5aebfc1..dd1af114e033 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -114,6 +114,11 @@ int arch_evlist__add_default_attrs(struct evlist *evlist);
struct evsel *arch_evlist__leader(struct list_head *list);

int evlist__add_dummy(struct evlist *evlist);
+struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide);
+static inline struct evsel *evlist__add_system_wide_dummy(struct evlist *evlist)
+{
+ return evlist__add_aux_dummy(evlist, true);
+}

int evlist__add_sb_event(struct evlist *evlist, struct perf_event_attr *attr,
evsel__sb_cb_t cb, void *data);
--
2.25.1