[tip: perf/urgent] perf record: Add --all-cgroups option

From: tip-bot2 for Namhyung Kim
Date: Sat Apr 04 2020 - 04:44:37 EST


The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: 8fb4b67939e169fca68174e9ac7be79fe9a04498
Gitweb: https://git.kernel.org/tip/8fb4b67939e169fca68174e9ac7be79fe9a04498
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
AuthorDate: Wed, 25 Mar 2020 21:45:34 +09:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Fri, 03 Apr 2020 09:37:55 -03:00

perf record: Add --all-cgroups option

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.

[root@seventh ~]# perf record --all-cgroups --namespaces /wb/cgtest
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.042 MB perf.data (558 samples) ]
[root@seventh ~]# perf report --stdio -s cgroup_id,cgroup,pid
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 558 of event 'cycles'
# Event count (approx.): 458017341
#
# Overhead cgroup id (dev/inode) Cgroup Pid:Command
# ........ ..................... .......... ...............
#
33.15% 4/0xeffffffb /sub 9615:looper0
32.83% 4/0xf00002f5 /sub/cgrp2 9620:looper2
32.79% 4/0xf00002f4 /sub/cgrp1 9619:looper1
0.35% 4/0xf00002f5 /sub/cgrp2 9618:cgtest
0.34% 4/0xf00002f4 /sub/cgrp1 9617:cgtest
0.32% 4/0xeffffffb / 9615:looper0
0.11% 4/0xeffffffb /sub 9617:cgtest
0.10% 4/0xeffffffb /sub 9618:cgtest

#
# (Tip: Sample related events with: perf record -e '{cycles,instructions}:S')
#
[root@seventh ~]#

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20200325124536.2800725-8-namhyung@xxxxxxxxxx
Link: http://lore.kernel.org/lkml/20200402015249.3800462-1-namhyung@xxxxxxxxxx
[ Extracted the HAVE_FILE_HANDLE from the followup patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 5 ++++-
tools/perf/builtin-record.c | 11 +++++++++++
tools/perf/util/evsel.c | 11 ++++++++++-
tools/perf/util/evsel.h | 1 +
tools/perf/util/record.h | 1 +
5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index b25e028..b3f3b3f 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -391,7 +391,10 @@ 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 2802de9..1ab349a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1433,6 +1433,15 @@ 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) {
+#ifdef HAVE_FILE_HANDLE
+ tool->cgroup_events = true;
+#else
+ pr_err("cgroup tracking is not supported\n");
+ return -1;
+#endif
+ }
+
if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.enabled) {
signal(SIGUSR2, snapshot_sig_handler);
if (rec->opts.auxtrace_snapshot_mode)
@@ -2363,6 +2372,8 @@ 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 b766eb6..eb880ef 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 @@ try_fallback:
* 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 3380474..53187c5 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 5421fd2..2431645 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;