perf hists browser: Support flat callchains

The flat callchain mode is to print all chains in a single, simple
hierarchy so make it easy to see.

Currently perf report --tui doesn't show flat callchains properly.  With
flat callchains, only leaf nodes are added to the final rbtree so it
should show entries in parent nodes.  To do that, add parent_val list to
struct callchain_node and show them along with the (normal) val list.

For example, consider following callchains with '-g graph'.

  $ perf report -g graph
  - 39.93%  swapper  [kernel.vmlinux]  [k] intel_idle
       intel_idle
       cpuidle_enter_state
       cpuidle_enter
       call_cpuidle
     - cpu_startup_entry
          28.63% start_secondary
        - 11.30% rest_init
             start_kernel
             x86_64_start_reservations
             x86_64_start_kernel

Before:
  $ perf report -g flat
  - 39.93%  swapper  [kernel.vmlinux]  [k] intel_idle
       28.63% start_secondary
     - 11.30% rest_init
          start_kernel
          x86_64_start_reservations
          x86_64_start_kernel

After:
  $ perf report -g flat
  - 39.93%  swapper  [kernel.vmlinux]  [k] intel_idle
     - 28.63% intel_idle
          cpuidle_enter_state
          cpuidle_enter
          call_cpuidle
          cpu_startup_entry
          start_secondary
     - 11.30% intel_idle
          cpuidle_enter_state
          cpuidle_enter
          call_cpuidle
          cpu_startup_entry
          start_kernel
          x86_64_start_reservations
          x86_64_start_kernel

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1447047946-1691-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 717c58c1da58..fc3b1e0d09ee 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -387,6 +387,7 @@ create_child(struct callchain_node *parent, bool inherit_children)
 	}
 	new->parent = parent;
 	INIT_LIST_HEAD(&new->val);
+	INIT_LIST_HEAD(&new->parent_val);
 
 	if (inherit_children) {
 		struct rb_node *n;
@@ -894,6 +895,11 @@ static void free_callchain_node(struct callchain_node *node)
 	struct callchain_node *child;
 	struct rb_node *n;
 
+	list_for_each_entry_safe(list, tmp, &node->parent_val, list) {
+		list_del(&list->list);
+		free(list);
+	}
+
 	list_for_each_entry_safe(list, tmp, &node->val, list) {
 		list_del(&list->list);
 		free(list);
@@ -917,3 +923,41 @@ void free_callchain(struct callchain_root *root)
 
 	free_callchain_node(&root->node);
 }
+
+int callchain_node__make_parent_list(struct callchain_node *node)
+{
+	struct callchain_node *parent = node->parent;
+	struct callchain_list *chain, *new;
+	LIST_HEAD(head);
+
+	while (parent) {
+		list_for_each_entry_reverse(chain, &parent->val, list) {
+			new = malloc(sizeof(*new));
+			if (new == NULL)
+				goto out;
+			*new = *chain;
+			new->has_children = false;
+			list_add_tail(&new->list, &head);
+		}
+		parent = parent->parent;
+	}
+
+	list_for_each_entry_safe_reverse(chain, new, &head, list)
+		list_move_tail(&chain->list, &node->parent_val);
+
+	if (!list_empty(&node->parent_val)) {
+		chain = list_first_entry(&node->parent_val, struct callchain_list, list);
+		chain->has_children = rb_prev(&node->rb_node) || rb_next(&node->rb_node);
+
+		chain = list_first_entry(&node->val, struct callchain_list, list);
+		chain->has_children = false;
+	}
+	return 0;
+
+out:
+	list_for_each_entry_safe(chain, new, &head, list) {
+		list_del(&chain->list);
+		free(chain);
+	}
+	return -ENOMEM;
+}