Quoting Tvrtko Ursulin (2020-07-29 15:22:26)
>
> On 29/07/2020 14:42, Chris Wilson wrote:
> >> parent = NULL;
> >> p = &ref->tree.rb_node;
> >> while (*p) {
> >> parent = *p;
> >>
> >> node = rb_entry(parent, struct active_node, node);
> >> if (node->timeline == idx) {
> >> kmem_cache_free(global.slab_cache, prealloc);
> >> goto out;
> >> }
> >>
> >> if (node->timeline < idx)
> >> p = &parent->rb_right;
> >> else
> >> p = &parent->rb_left;
> >> WRITE_ONCE(ref->cache, it);
> >> break;
> >> }
> >> }
> >> ...
> >>
> >> Tree walk could be consolidated between the two.
> >
> > This tree walk is subtly different, as we aren't just interested in the
> > node, but its parent. The exact repetitions have been consolidated into
> > __active_lookup.
>
> It returns the previous/parent node if idx is not found so yeah, common
> helper would need to have two out parameters. One returns the match, or
> NULL, another returns the previous/parent node. You think that is not
> worth it?
I remember in the past wanting to keep the lookup separate from
insertion as the compiler generated better code if we didn't track the
parent pointer.
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
