On Fri, Jul 27, 2012 at 8:57 PM, John Stultz [off-list ref] wrote:

v5:
* Drop intervaltree for prio_tree usage per Michel &
  Dmitry's suggestions.

Actually, I believe the ranges you need to track are non-overlapping, correct ?

If that is the case, a simple rbtree, sorted by start-of-range
address, would work best.
(I am trying to remove prio_tree users... :)

+       /* First, find any existing intervals that overlap */
+       prio_tree_iter_init(&iter, root, start, end);

Note that prio tree iterations take intervals as [start; last] not [start; end[
So if you want to stick with prio trees, you would have to use end-1 here.

+       /* Coalesce left-adjacent ranges */
+       prio_tree_iter_init(&iter, root, start-1, start);

Same here; you probably want to use start-1 on both ends

+       node = prio_tree_next(&iter);
+       while (node) {

I'm confused, I don't think you ever expect more than one range to
match, do you ???

+       /* Coalesce right-adjacent ranges */
+       prio_tree_iter_init(&iter, root, end, end+1);

Same again, here you probably want end on both ends

This is far from a complete code review, but I just wanted to point
out a couple details that jumped to me first. I am afraid I am missing
some of the background about how the feature is to be used to really
dig into the rest of the changes at this point :/

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>