Re: [PATCH 3/7] perf callchain: Add enum match_result for match_chain()

From: Namhyung Kim
Date: Sat Jan 23 2016 - 23:06:29 EST


Hi Jiri,

On Sat, Jan 23, 2016 at 06:01:10PM +0100, Jiri Olsa wrote:
> On Fri, Jan 22, 2016 at 10:41:36PM +0900, Namhyung Kim wrote:
>
> SNIP
>
> > /* lookup in childrens */
> > while (*p) {
> > - s64 ret;
> > + enum match_result ret;
> >
> > parent = *p;
> > rnode = rb_entry(parent, struct callchain_node, rb_node_in);
> >
> > /* If at least first entry matches, rely to children */
> > ret = append_chain(rnode, cursor, period);
> > - if (ret == 0)
> > + if (ret == MATCH_EQ)
> > goto inc_children_hit;
> >
> > - if (ret < 0)
> > + if (ret == MATCH_LT)
> > p = &parent->rb_left;
> > else
> > p = &parent->rb_right;
>
> so if we want to use the return values like that you
> probably missed 2 other places

Right!

>
>
> ---
> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
> index 7139d438ee6d..dc08e76aa8d9 100644
> --- a/tools/perf/util/callchain.c
> +++ b/tools/perf/util/callchain.c
> @@ -565,7 +565,7 @@ split_add_child(struct callchain_node *parent,
> cnode = list_first_entry(&first->val, struct callchain_list,
> list);
>
> - if (match_chain(node, cnode) < 0)
> + if (match_chain(node, cnode) == MATCH_LT)
> pp = &p->rb_left;
> else
> pp = &p->rb_right;
> @@ -652,7 +652,7 @@ append_chain(struct callchain_node *root,
> break;
>
> cmp = match_chain(node, cnode);
> - if (cmp)
> + if (cmp != MATCH_EQ)

This has same effect since I chose 0 for MATCH_EQ intentionally. But
yes, it'd be better making it explicit. Will change.

Thanks,
Namhyung


> break;
>
> found = true;