perf hists browser: replace rb_first() != NULL by !RB_EMPTY_ROOT()

Its way too stupid to use rb_first() for just caching if there are
children, use the cheaper RB_EMPTY_ROOT() instead.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index 39ba230972bb4a31503d0223a3c549ec41d1adf1..e61355e6b2c56e059f0c5b2409e1d89873dc98b5 100644 (file)
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -129,16 +129,16 @@ static void callchain_node__init_have_children_rb_tree(struct callchain_node *se
        for (nd = rb_first(&self->rb_root); nd; nd = rb_next(nd)) {
                struct callchain_node *child = rb_entry(nd, struct callchain_node, rb_node);
                struct callchain_list *chain;
-               int first = true;
+               bool first = true;
 
                list_for_each_entry(chain, &child->val, list) {
                        if (first) {
                                first = false;
                                chain->ms.has_children = chain->list.next != &child->val ||
-                                                        rb_first(&child->rb_root) != NULL;
+                                                        !RB_EMPTY_ROOT(&child->rb_root);
                        } else
                                chain->ms.has_children = chain->list.next == &child->val &&
-                                                        rb_first(&child->rb_root) != NULL;
+                                                        !RB_EMPTY_ROOT(&child->rb_root);
                }
 
                callchain_node__init_have_children_rb_tree(child);
@@ -150,7 +150,7 @@ static void callchain_node__init_have_children(struct callchain_node *self)
        struct callchain_list *chain;
 
        list_for_each_entry(chain, &self->val, list)
-               chain->ms.has_children = rb_first(&self->rb_root) != NULL;
+               chain->ms.has_children = !RB_EMPTY_ROOT(&self->rb_root);
 
        callchain_node__init_have_children_rb_tree(self);
 }
@@ -301,11 +301,11 @@ static int hist_browser__show_callchain_node_rb_tree(struct hist_browser *self,
                        if (first) {
                                first = false;
                                chain->ms.has_children = chain->list.next != &child->val ||
-                                                        rb_first(&child->rb_root) != NULL;
+                                                        !RB_EMPTY_ROOT(&child->rb_root);
                        } else {
                                extra_offset = LEVEL_OFFSET_STEP;
                                chain->ms.has_children = chain->list.next == &child->val &&
-                                                        rb_first(&child->rb_root) != NULL;
+                                                        !RB_EMPTY_ROOT(&child->rb_root);
                        }
 
                        folded_sign = callchain_list__folded(chain);
@@ -381,7 +381,7 @@ static int hist_browser__show_callchain_node(struct hist_browser *self,
                 * probably when the callchain is created, so as not to
                 * traverse it all over again
                 */
-               chain->ms.has_children = rb_first(&node->rb_root) != NULL;
+               chain->ms.has_children = !RB_EMPTY_ROOT(&node->rb_root);
                folded_sign = callchain_list__folded(chain);
 
                if (*row_offset != 0) {