[PATCH 1/2] perf hists: Fix determination of a callchain node's childlessness

From: Arnaldo Carvalho de Melo
Date: Wed Mar 30 2016 - 18:14:14 EST

From: Andres Freund <andres@xxxxxxxxxxx>

The 4b3a3212233a ("perf hists browser: Support flat callchains") commit
over-aggressively tried to optimize callchain_node__init_have_children().

That lead to --tui mode not allowing to expand call chain elements if a
call chain element had only one parent. That's why --inverted callgraphs
looked halfway sane, but plain ones didn't.

Revert that individual optimization, it wasn't really related to the
rest of the commit.

Signed-off-by: Andres Freund <andres@xxxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Fixes: 4b3a3212233a ("perf hists browser: Support flat callchains")
Link: http://lkml.kernel.org/r/20160330190245.GB13305@xxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/ui/browsers/hists.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 4b9816555946..2a83414159a6 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -337,7 +337,7 @@ static void callchain_node__init_have_children(struct callchain_node *node,
chain = list_entry(node->val.next, struct callchain_list, list);
chain->has_children = has_sibling;

- if (node->val.next != node->val.prev) {
+ if (!list_empty(&node->val)) {
chain = list_entry(node->val.prev, struct callchain_list, list);
chain->has_children = !RB_EMPTY_ROOT(&node->rb_root);