On Wed, Sep 02, 2015 at 08:05:54PM +0800, pi3orama wrote: SNIP
> >>> perf_evlist__splice_list_tail(evlist, &data.list, entries); > >>> evlist->nr_groups += data.nr_groups; > >>> - last = perf_evlist__last(evlist); > >>> - last->cmdline_group_boundary = true; > >>> return 0; > >>> } > >>> @@ -1252,7 +1262,13 @@ foreach_evsel_in_last_glob(struct perf_evlist > >>> *evlist, > >>> struct perf_evsel *last = NULL; > >>> int err; > >>> - if (evlist->nr_entries > 0) > >>> + /* > >>> + * Don't return when list_empty, give func a chance to report > >>> + * error when it found last == NULL. > >>> + * > >>> + * So no need to WARN here, let *func do this. > >>> + */ > >>> + if (!list_empty(&evlist->entries)) > > > > why is it better than to check evlist->nr_entries? > > evlist->nr_entries is equivalent to !list_empty(&evlist->entries) in here, > > right? > > > > By checking list we won't rely on the assumption that nr_entries reflects the > actual number of elements in that list, makes the logic of this code more > compact. > Don't you think so? > > At this point they are equivalent, but the whole patch is preventive action. ok, fair enough ;-) Acked-by: Jiri Olsa <jo...@kernel.org> thanks, jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
