Re: [PATCH v2 2/8] perf tools: Introduce perf_hpp__setup_hists_formats()

[Namhyung Kim <namhyung@kernel.org>]

On Sun, Mar 06, 2016 at 07:43:25PM +0100, Jiri Olsa wrote:
> On Fri, Mar 04, 2016 at 11:59:36PM +0900, Namhyung Kim wrote:
> 
> SNIP
> 
> >  
> > @@ -2133,8 +2134,19 @@ static void hists__delete_all_entries(struct hists *hists)
> >  static void hists_evsel__exit(struct perf_evsel *evsel)
> >  {
> >  	struct hists *hists = evsel__hists(evsel);
> > +	struct perf_hpp_fmt *fmt, *pos;
> > +	struct perf_hpp_list_node *node;
> >  
> >  	hists__delete_all_entries(hists);
> > +
> > +	list_for_each_entry(node, &hists->hpp_formats, list) {
> > +		perf_hpp_list__for_each_format_safe(&node->hpp, fmt, pos) {
> > +			list_del(&fmt->list);
> > +			free(fmt);
> > +		}
> > +		list_del(&node->list);
> > +		free(node);
> > +	}
> >  }
> >  
> >  static int hists_evsel__init(struct perf_evsel *evsel)
> > diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
> > index f4ef513527ba..3cab9dc20822 100644
> > --- a/tools/perf/util/hist.h
> > +++ b/tools/perf/util/hist.h
> > @@ -78,6 +78,7 @@ struct hists {
> >  	u16			col_len[HISTC_NR_COLS];
> >  	int			socket_filter;
> >  	struct perf_hpp_list	*hpp_list;
> > +	struct list_head	hpp_formats;
> 
> I've been thinking.. should hpp_formats and hpp_list be merged? something like:
> 
> struct perf_hpp_list {
> 	struct list_head nodes;
> 	int levels;
> }
> 
> sturct perf_hpp_list_node {
> 	int level;
> 	struct list_head fields;
> 	struct list_head sorts;
> 	int nr_sort_keys;
> };
> 
> it seems wrong to me that your hierarchy code and current one
> got in separate paths.. we could have the new hierarchy support
> struct above being used in current non-hierarchy code just
> by using single level
> 
> I haven't thought all this through.. just an idea ;-)

Yes, I also think that we need to converge on the same data structure
eventually.  But I think it's too intrusive to be merged at once.
Also keeping up with the latest perf changes is a PITA.  ;-)

So I decided to use it on the hierarchy first, and get tested in the
wild for some time.  After that we can convert the non-hierarchy code
to use same path and data structure gradually IMHO.

Thanks,
Namhyung