On Tue, Jul 05, 2016 at 10:44:48AM +0100, Mark Rutland wrote:
> My bad; I assumed that for both PMUs we'd start at the root, and thus
> would need to re-sort in order to get the current CPU's PMU ordered
> first, much like currently with rotation.
>
> I guess I'm having difficulty figuring out the structure of that tree.
> If we can easily/cheaply find the relevant sub-tree then the above isn't
> an issue.
struct event {
struct rb_node node;
int pmu_id;
s64 lag;
...
};
bool event_less(struct rb_node *a, struct rb_node *b)
{
struct event *left = rb_entry(a, struct event, node);
struct event *right = rb_entry(b, struct event, node);
if (a->pmu_id < b->pmu_id)
return true;
if (b->pmu_id > a->pmu_id)
return false;
/* a->pmu_id == b->pmu_id */
if (a->lag < b->lag)
return true;
return false;
}
Will give you a tree with primary order @pmu_id and secondary order
@lag.
Which you'd iterate like:
for (event = event_find(pmu_id); event->pmu_id == pmu_id; event =
event_next(event)) {
}
And get only the events matching @pmu_id in @lag order.
