On Mon, Jun 19, 2017 at 11:31:59PM +0300, Alexey Budankov wrote:
> On 15.06.2017 22:56, Mark Rutland wrote:
> >On Thu, Jun 15, 2017 at 08:41:42PM +0300, Alexey Budankov wrote:
> >>+static int
> >>+perf_cpu_tree_iterate(struct rb_root *tree,
> >>+ perf_cpu_tree_callback_t callback, void *data)
> >>+{
> >>+ int ret = 0;
> >>+ struct rb_node *node;
> >>+ struct perf_event *event;
> >>+
> >>+ WARN_ON_ONCE(!tree);
> >>+
> >>+ for (node = rb_first(tree); node; node = rb_next(node)) {
> >>+ struct perf_event *node_event = container_of(node,
> >>+ struct perf_event, group_node);
> >>+
> >>+ list_for_each_entry(event, &node_event->group_list,
> >>+ group_list_entry) {
> >>+ ret = callback(event, data);
> >>+ if (ret)
> >>+ return ret;
> >>+ }
> >>+ }
> >>+
> >>+ return 0;
> >> }
> >
> >If you need to iterate over every event, you can use the list that
> >threads the whole tree.
>
> Could you please explain more on that?
In Peter's original suggestion, we'd use a threaded tree rather than a
tree of lists.
i.e. you'd have something like:
struct threaded_rb_node {
struct rb_node node;
struct list_head head;
};
... with the tree and list covering all nodes, in the same order:
Tree:
3
/ \
/ \
1 5
/ \ / \
0 2 4 6
List:
0 - 1 - 2 - 3 - 4 - 5 - 6
... that way you can search using the tree, and iterate using the list,
even when you wan to iterate over sub-lists.
Thanks,
Mark.
