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

From: Namhyung Kim
Date: Wed Mar 25 2020 - 08:46:11 EST


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-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