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

[Ivan Babrou]

On Mon, Jul 17, 2023 at 5:07 PM Ivan Babrou <ivan@xxxxxxxxxxxxxx> wrote:
>
> 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
>

A friendly bump in case this slipped through the cracks.