From: Namhyung Kim <[email protected]>
[ Upstream commit aa50d953c169e876413bf237319e728dd41d9fdd ]
It didn't check the tool->cgroup_events bit which is set when the
--all-cgroups option is given. Without it, samples will not have cgroup
info so no reason to synthesize.
We can check the PERF_RECORD_CGROUP records after running perf record
*WITHOUT* the --all-cgroups option:
Before:
$ perf report -D | grep CGROUP
0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
CGROUP events: 1
CGROUP events: 0
CGROUP events: 0
After:
$ perf report -D | grep CGROUP
CGROUP events: 0
CGROUP events: 0
CGROUP events: 0
Committer testing:
Before:
# perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.208 MB perf.data (10003 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 146
CGROUP events: 0
CGROUP events: 0
#
After:
# perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.208 MB perf.data (10448 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 0
CGROUP events: 0
CGROUP events: 0
#
With all-cgroups:
# perf record --all-cgroups -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.374 MB perf.data (11526 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 146
CGROUP events: 0
CGROUP events: 0
#
Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option")
Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
tools/perf/util/synthetic-events.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/perf/util/synthetic-events.c
b/tools/perf/util/synthetic-events.c
index 89b390623b63d..54ca751a2b3b3 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool *tool,
char cgrp_root[PATH_MAX];
size_t mount_len; /* length of mount point in the path */
+ if (!tool || !tool->cgroup_events)
+ return 0;
+
if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX, "perf_event") < 0) {
pr_debug("cannot find cgroup mount point\n");
return -1;
--
2.27.0
