Re: [PATCH v3 1/3] perf evlist: Create a new function perf_evlist_forced_leader

[Jin, Yao]

On 5/18/2018 10:18 PM, Arnaldo Carvalho de Melo wrote:
> Em Sat, May 19, 2018 at 12:00:32AM +0800, Jin Yao escreveu:
> > For non-explicit group, perf report supports a option '--group'
> > which can enable group output. We also need to support perf annotate
> > with the same '--group'.
> >
> > Create a new function perf_evlist_forced_leader which contains
> > common code to force setting the group leader.
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/util/evlist.c | 15 +++++++++++++++
> >   tools/perf/util/evlist.h |  3 +++
> >   2 files changed, 18 insertions(+)
> >
> > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> > index a59281d..6983f6a 100644
> > --- a/tools/perf/util/evlist.c
> > +++ b/tools/perf/util/evlist.c
> > @@ -1795,3 +1795,18 @@ bool perf_evlist__exclude_kernel(struct perf_evlist *evlist)
> >   
> >   	return true;
> >   }
> > +
> > +/*
> > + * Events in data file are not collect in groups, but we still want
> > + * the group display. Set the artificial group and set the leader's
> > + * forced_leader flag to notify the display code.
> > + */
> > +void perf_evlist_forced_leader(struct perf_evlist *evlist)
>
> This should've been:
>
> void perf_evlist__forced_leader(struct perf_evlist *evlist)
>
> But then, by the verb conjugation, I thought that this would be a query,
> i.e. "is this a forced leader?", but then, it returning void didn't
> match that expectation, which leads me having to actually _read_ that
> code to understand what is that this function does, which I would, but
> just to check that it matches what it seems to be, now I'm trying to do
> it to figure it out what is it that this thing does :-\
>
>
> I see, its a 'd' to many, this should be:
>
> void perf_evlist__force_leader(struct perf_evlist *evlist)
>
> Please confirm that this is what you intend by posting a v4, so far,
> just for this specific patch and any other in the series that uses this
> function, ok?
>
> - Arnaldo

Yes, the function is not a query, it's just to setup the forced_leader.

Maybe we can use the name "perf_evlist__setup_forced_leader". But it 
looks the name is long so the name "perf_evlist__force_leader" is also good.

I will use the name "perf_evlist__force_leader" in v4.

Thanks
Jin Yao



> > +{
> > +	if (!evlist->nr_groups) {
> > +		struct perf_evsel *leader = perf_evlist__first(evlist);
> > +
> > +		perf_evlist__set_leader(evlist);
> > +		leader->forced_leader = true;
> > +	}
> > +}
> > diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
> > index 6c41b2f..d77d514 100644
> > --- a/tools/perf/util/evlist.h
> > +++ b/tools/perf/util/evlist.h
> > @@ -309,4 +309,7 @@ struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist,
> >   					    union perf_event *event);
> >   
> >   bool perf_evlist__exclude_kernel(struct perf_evlist *evlist);
> > +
> > +void perf_evlist_forced_leader(struct perf_evlist *evlist);
> > +
> >   #endif /* __PERF_EVLIST_H */
> > --
> > 2.7.4