Re: [PATCH v3] tools/perf/metricgroup: Fix printing event names of metric group with multiple events incase of overlapping events

[Jiri Olsa <jolsa@redhat.com>]

On Thu, Feb 06, 2020 at 10:58:12AM -0800, Joe Perches wrote:
> On Thu, 2020-02-06 at 19:45 +0100, Jiri Olsa wrote:
> > On Fri, Jan 31, 2020 at 10:55:22AM +0530, Kajol Jain wrote:
> > 
> > SNIP
> > 
> > >  				ev->metric_leader = metric_events[i];
> > >  			}
> > > +			j++;
> > >  		}
> > > +		ev = metric_events[i];
> > > +		evlist_used[ev->idx] = true;
> > >  	}
> > >  
> > >  	return metric_events[0];
> > > @@ -160,6 +161,9 @@ static int metricgroup__setup_events(struct list_head *groups,
> > >  	int ret = 0;
> > >  	struct egroup *eg;
> > >  	struct evsel *evsel;
> > > +	bool evlist_used[perf_evlist->core.nr_entries];
> > > +
> > > +	memset(evlist_used, 0, perf_evlist->core.nr_entries);
> > 
> > I know I posted this in the previous email, but are we sure bool
> > is always 1 byte?  would sizeod(evlist_used) be safer?
> > 
> > other than that it looks ok
> > 
> > Andi, you're ok with this?
> 
> stack declarations of variable length arrays are not
> a good thing.
> 
> https://lwn.net/Articles/749089/
> 
> and
> 
> 	bool evlist_used[perf_evlist->core.nr_entries] = {};

hum, I think we already have few of them in perf ;-)
thanks for the link

right, that initialization is of course much better, thanks

jirka