Re: [PATCH v3 1/3] perf report: Change sort order by a specified event in group

[Jiri Olsa]

On Tue, Dec 17, 2019 at 09:47:01AM +0800, Jin, Yao wrote:
> 
> 
> On 12/16/2019 3:31 PM, Jiri Olsa wrote:
> > On Thu, Dec 12, 2019 at 08:33:35PM +0800, Jin Yao wrote:
> > 
> > SNIP
> > 
> > > 
> > > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > > ---
> > >   tools/perf/Documentation/perf-report.txt |   4 +
> > >   tools/perf/builtin-report.c              |  10 +++
> > >   tools/perf/ui/hist.c                     | 108 +++++++++++++++++++----
> > >   tools/perf/util/symbol_conf.h            |   1 +
> > >   4 files changed, 108 insertions(+), 15 deletions(-)
> > > 
> > > diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
> > > index 8dbe2119686a..9ade613ef020 100644
> > > --- a/tools/perf/Documentation/perf-report.txt
> > > +++ b/tools/perf/Documentation/perf-report.txt
> > > @@ -371,6 +371,10 @@ OPTIONS
> > >   	Show event group information together. It forces group output also
> > >   	if there are no groups defined in data file.
> > > +--group-sort-idx::
> > > +	Sort the output by the event at the index n in group. If n is invalid,
> > > +	sort by the first event. WARNING: This should be used with --group.
> > 
> > --group in record or report?
> > 
> 
> This --group is in perf-report. So even if it's not created with -e '{}' in
> perf-record, it still supports to show event information together.
> 
> > you can also create groups with -e '{}', not just --group option
> > 
> > I wonder you could check early on 'evlist->nr_groups' and fail
> > if there's no group defined if the option is enabled
> > 
> 
> Maybe we don't need to check that because it supports the case of no group
> defined.
> 
> For example,
> perf record -e cycles,instructions
> perf report --group --group-sort-idx 1 --stdio

hum, --group will force evlist->nr_groups == 1, right?

so we could warn/fail on (group-sort-idx && !evlist->nr_groups)


SNIP

> 
> Thanks. Can we say something as following?
> 
> --group-sort-idx::
> 	Sort the output by the event at the index n in group. If n is invalid, sort
> by the first event. It can support multiple groups with different amount of
> events. WARNING: This should be used with perf report --group.

if the events are already grouped you dont need --group ;-) how about:

	This should be used on grouped events.

thanks,
jirka