[PATCH 7/9] perf record: Add --all-cgroups option

From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: [PATCH 7/9] perf record: Add --all-cgroups option
Date: Wed, 25 Mar 2020 21:45:34 +0900	[thread overview]
Message-ID: <20200325124536.2800725-8-namhyung@kernel.org> (raw)
In-Reply-To: <20200325124536.2800725-1-namhyung@kernel.org>

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@kernel.org>
---
 tools/perf/Documentation/perf-record.txt |  5 ++++-
 tools/perf/builtin-record.c              |  5 +++++
 tools/perf/util/evsel.c                  | 11 ++++++++++-
 tools/perf/util/evsel.h                  |  1 +
 tools/perf/util/record.h                 |  1 +
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 7f4db7592467..eba9beec80e6 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -385,7 +385,10 @@ displayed with the weight and local_weight sort keys.  This currently works for
 abort events and some memory events in precise mode on modern Intel CPUs.
 
 --namespaces::
-Record events of type PERF_RECORD_NAMESPACES.
+Record events of type PERF_RECORD_NAMESPACES.  This enables 'cgroup_id' sort key.
+
+--all-cgroups::
+Record events of type PERF_RECORD_CGROUP.  This enables 'cgroup' sort key.
 
 --transaction::
 Record transaction flags for transaction related events.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 2802de9538ff..7d7912e121d6 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1433,6 +1433,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	if (rec->opts.record_namespaces)
 		tool->namespace_events = true;
 
+	if (rec->opts.record_cgroup)
+		tool->cgroup_events = true;
+
 	if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.enabled) {
 		signal(SIGUSR2, snapshot_sig_handler);
 		if (rec->opts.auxtrace_snapshot_mode)
@@ -2363,6 +2366,8 @@ static struct option __record_options[] = {
 			"per thread proc mmap processing timeout in ms"),
 	OPT_BOOLEAN(0, "namespaces", &record.opts.record_namespaces,
 		    "Record namespaces events"),
+	OPT_BOOLEAN(0, "all-cgroups", &record.opts.record_cgroup,
+		    "Record cgroup events"),
 	OPT_BOOLEAN(0, "switch-events", &record.opts.record_switch_events,
 		    "Record context switch events"),
 	OPT_BOOLEAN_FLAG(0, "all-kernel", &record.opts.all_kernel,
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index b766eb608b97..eb880efbce16 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1104,6 +1104,11 @@ void perf_evsel__config(struct evsel *evsel, struct record_opts *opts,
 	if (opts->record_namespaces)
 		attr->namespaces  = track;
 
+	if (opts->record_cgroup) {
+		attr->cgroup = track && !perf_missing_features.cgroup;
+		perf_evsel__set_sample_bit(evsel, CGROUP);
+	}
+
 	if (opts->record_switch_events)
 		attr->context_switch = track;
 
@@ -1789,7 +1794,11 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 	 * Must probe features in the order they were added to the
 	 * perf_event_attr interface.
 	 */
-	if (!perf_missing_features.branch_hw_idx &&
+        if (!perf_missing_features.cgroup && evsel->core.attr.cgroup) {
+		perf_missing_features.cgroup = true;
+		pr_debug2_peo("Kernel has no cgroup sampling support, bailing out\n");
+		goto out_close;
+        } else if (!perf_missing_features.branch_hw_idx &&
 	    (evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX)) {
 		perf_missing_features.branch_hw_idx = true;
 		pr_debug2("switching off branch HW index support\n");
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 33804740e2ca..53187c501ee8 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -120,6 +120,7 @@ struct perf_missing_features {
 	bool bpf;
 	bool aux_output;
 	bool branch_hw_idx;
+	bool cgroup;
 };
 
 extern struct perf_missing_features perf_missing_features;
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index 5421fd2ad383..24316458be20 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -34,6 +34,7 @@ struct record_opts {
 	bool	      auxtrace_snapshot_on_exit;
 	bool	      auxtrace_sample_mode;
 	bool	      record_namespaces;
+	bool	      record_cgroup;
 	bool	      record_switch_events;
 	bool	      all_kernel;
 	bool	      all_user;
-- 
2.25.1.696.g5e7596f4ac-goog

