[PATCH 8/9] perf top: Add --all-cgroups option

[Namhyung Kim]

The --all-cgroups option is to enable cgroup profiling support.  It
tells kernel to record CGROUP events in the ring buffer so that perf
report can identify task/cgroup association later.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-top.txt | 4 ++++
 tools/perf/builtin-top.c              | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index 5596129a71cf..c75507f50071 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -266,6 +266,10 @@ Default is to monitor all CPUS.
 	Record events of type PERF_RECORD_NAMESPACES and display it with the
 	'cgroup_id' sort key.
 
+--cgroup::
+	Record events of type PERF_RECORD_CGROUP and display it with the
+	'cgroup' sort key.
+
 --switch-on EVENT_NAME::
 	Only consider events after this event is found.
 
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5970723cd55a..f07b43c12461 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1242,6 +1242,8 @@ static int __cmd_top(struct perf_top *top)
 
 	if (opts->record_namespaces)
 		top->tool.namespace_events = true;
+	if (opts->record_cgroup)
+		top->tool.cgroup_events = true;
 
 	ret = perf_event__synthesize_bpf_events(top->session, perf_event__process,
 						&top->session->machines.host,
@@ -1249,6 +1251,11 @@ static int __cmd_top(struct perf_top *top)
 	if (ret < 0)
 		pr_debug("Couldn't synthesize BPF events: Pre-existing BPF programs won't have symbols resolved.\n");
 
+	ret = perf_event__synthesize_cgroups(&top->tool, perf_event__process,
+					     &top->session->machines.host);
+	if (ret < 0)
+		pr_debug("Couldn't synthesize cgroup events.\n");
+
 	machine__synthesize_threads(&top->session->machines.host, &opts->target,
 				    top->evlist->core.threads, false,
 				    top->nr_threads_synthesize);
@@ -1537,6 +1544,8 @@ int cmd_top(int argc, const char **argv)
 			"number of thread to run event synthesize"),
 	OPT_BOOLEAN(0, "namespaces", &opts->record_namespaces,
 		    "Record namespaces events"),
+	OPT_BOOLEAN(0, "all-cgroups", &opts->record_cgroup,
+		    "Record cgroup events"),
 	OPTS_EVSWITCH(&top.evswitch),
 	OPT_END()
 	};
-- 
2.23.0.187.g17f5b7556c-goog