[PATCH] perf script: print cgroup on the same line as comm

From: Ivan Babrou
Date: Mon Jul 17 2023 - 20:07:51 EST


Commit 3fd7a168bf51 ("perf script: Add 'cgroup' field for output")
added support for printing cgroup path in perf script output.

It was okay if you didn't want any stacks:

$ sudo perf script --comms jpegtran:23f4bf -F comm,tid,cpu,time,cgroup
jpegtran:23f4bf 3321915 [013] 404718.587488: /idle.slice/polish.service
jpegtran:23f4bf 3321915 [031] 404718.592073: /idle.slice/polish.service

With stacks it gets messier as cgroup is printed after the stack:

$ perf script --comms jpegtran:23f4bf -F comm,tid,cpu,time,cgroup,ip,sym
jpegtran:23f4bf 3321915 [013] 404718.587488:
5c554 compress_output
570d9 jpeg_finish_compress
3476e jpegtran_main
330ee jpegtran::main
326e2 core::ops::function::FnOnce::call_once (inlined)
326e2 std::sys_common::backtrace::__rust_begin_short_backtrace
/idle.slice/polish.service
jpegtran:23f4bf 3321915 [031] 404718.592073:
8474d jsimd_encode_mcu_AC_first_prepare_sse2.PADDING
55af68e62fff [unknown]
/idle.slice/polish.service

Let's instead print cgroup on the same line as comm:

$ perf script --comms jpegtran:23f4bf -F comm,tid,cpu,time,cgroup,ip,sym
jpegtran:23f4bf 3321915 [013] 404718.587488: /idle.slice/polish.service
5c554 compress_output
570d9 jpeg_finish_compress
3476e jpegtran_main
330ee jpegtran::main
326e2 core::ops::function::FnOnce::call_once (inlined)
326e2 std::sys_common::backtrace::__rust_begin_short_backtrace

jpegtran:23f4bf 3321915 [031] 404718.592073: /idle.slice/polish.service
8474d jsimd_encode_mcu_AC_first_prepare_sse2.PADDING
55af68e62fff [unknown]

Signed-off-by: Ivan Babrou <ivan@xxxxxxxxxxxxxx>
Fixes: 3fd7a168bf51 ("perf script: Add 'cgroup' field for output")
---
tools/perf/builtin-script.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 200b3e7ea8da..517bf25750c8 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -2199,6 +2199,17 @@ static void process_event(struct perf_script *script,
if (PRINT_FIELD(RETIRE_LAT))
fprintf(fp, "%16" PRIu16, sample->retire_lat);

+ if (PRINT_FIELD(CGROUP)) {
+ const char *cgrp_name;
+ struct cgroup *cgrp = cgroup__find(machine->env,
+ sample->cgroup);
+ if (cgrp != NULL)
+ cgrp_name = cgrp->name;
+ else
+ cgrp_name = "unknown";
+ fprintf(fp, " %s", cgrp_name);
+ }
+
if (PRINT_FIELD(IP)) {
struct callchain_cursor *cursor = NULL;

@@ -2243,17 +2254,6 @@ static void process_event(struct perf_script *script,
if (PRINT_FIELD(CODE_PAGE_SIZE))
fprintf(fp, " %s", get_page_size_name(sample->code_page_size, str));

- if (PRINT_FIELD(CGROUP)) {
- const char *cgrp_name;
- struct cgroup *cgrp = cgroup__find(machine->env,
- sample->cgroup);
- if (cgrp != NULL)
- cgrp_name = cgrp->name;
- else
- cgrp_name = "unknown";
- fprintf(fp, " %s", cgrp_name);
- }
-
perf_sample__fprintf_ipc(sample, attr, fp);

fprintf(fp, "\n");
--
2.41.0