Currently pipe mode doesn't set the file size and it results in a
misleading message of 0 data size at the end.  Although it might miss
some accounting for pipe header or more, just displaying the data size
would reduce the possible confusion.

Before:
  $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]    <======  (here)
      99.58%  perf     perf                  [.] noploop

After:
  $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.229 MB - ]
      99.46%  perf     perf                  [.] noploop

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-record.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 91e6828c38cc..21ebcb04f1d8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1773,8 +1773,11 @@ record__finish_output(struct record *rec)
 	struct perf_data *data = &rec->data;
 	int fd = perf_data__fd(data);
 
-	if (data->is_pipe)
+	if (data->is_pipe) {
+		/* Just to display approx. size */
+		data->file.size = rec->bytes_written;
 		return;
+	}
 
 	rec->session->header.data_size += rec->bytes_written;
 	data->file.size = lseek(perf_data__fd(data), 0, SEEK_CUR);
-- 
2.43.0.275.g3460e3d667-goog

On Fri, 12 Jan 2024 15:13:40 -0800, Namhyung Kim wrote:
> Currently pipe mode doesn't set the file size and it results in a
> misleading message of 0 data size at the end.  Although it might miss
> some accounting for pipe header or more, just displaying the data size
> would reduce the possible confusion.
> 
> Before:
>   $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.000 MB - ]    <======  (here)
>       99.58%  perf     perf                  [.] noploop
> 
> [...]

Applied to perf-tools-next, thanks!

Best regards,
-- 
Namhyung Kim <namhyung@kernel.org>

On Fri, Jan 12, 2024 at 3:13 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Currently pipe mode doesn't set the file size and it results in a
> misleading message of 0 data size at the end.  Although it might miss
> some accounting for pipe header or more, just displaying the data size
> would reduce the possible confusion.
>
> Before:
>   $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.000 MB - ]    <======  (here)
>       99.58%  perf     perf                  [.] noploop
>
> After:
>   $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.229 MB - ]
>       99.46%  perf     perf                  [.] noploop
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  tools/perf/builtin-record.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 91e6828c38cc..21ebcb04f1d8 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1773,8 +1773,11 @@ record__finish_output(struct record *rec)
>         struct perf_data *data = &rec->data;
>         int fd = perf_data__fd(data);
>
> -       if (data->is_pipe)
> +       if (data->is_pipe) {
> +               /* Just to display approx. size */
> +               data->file.size = rec->bytes_written;
>                 return;
> +       }
>
>         rec->session->header.data_size += rec->bytes_written;
>         data->file.size = lseek(perf_data__fd(data), 0, SEEK_CUR);
> --
> 2.43.0.275.g3460e3d667-goog
>

Ping!

On Fri, Jan 12, 2024 at 3:13 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Currently pipe mode doesn't set the file size and it results in a
> misleading message of 0 data size at the end.  Although it might miss
> some accounting for pipe header or more, just displaying the data size
> would reduce the possible confusion.
>
> Before:
>   $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.000 MB - ]    <======  (here)
>       99.58%  perf     perf                  [.] noploop
>
> After:
>   $ perf record -o- perf test -w noploop | perf report -i- -q --percent-limit=1
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 0.229 MB - ]
>       99.46%  perf     perf                  [.] noploop
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/builtin-record.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 91e6828c38cc..21ebcb04f1d8 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1773,8 +1773,11 @@ record__finish_output(struct record *rec)
>         struct perf_data *data = &rec->data;
>         int fd = perf_data__fd(data);
>
> -       if (data->is_pipe)
> +       if (data->is_pipe) {
> +               /* Just to display approx. size */
> +               data->file.size = rec->bytes_written;
>                 return;
> +       }
>
>         rec->session->header.data_size += rec->bytes_written;
>         data->file.size = lseek(perf_data__fd(data), 0, SEEK_CUR);
> --
> 2.43.0.275.g3460e3d667-goog
>
>