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

[Ian Rogers]

On Fri, Jul 28, 2023 at 10:42 AM Ivan Babrou <ivan@xxxxxxxxxxxxxx> wrote:
>
> 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")

This change makes sense to me. Namhyung, wdyt?

Thanks,
Ian


> > ---
> >  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.