On Wed, Oct 09, 2019 at 04:44:19PM -0700, Jonathan Tan wrote:

-static void prune_base_data(struct base_data *retain)
+static void prune_base_data(struct base_data *youngest_child)
 {
 	struct base_data *b;
 	struct thread_local *data = get_thread_data();
-	for (b = data->base_cache;
-	     data->base_cache_used > delta_base_cache_limit && b;
-	     b = b->child) {
-		if (b->data && b != retain)
-			free_base_data(b);
+	struct base_data **ancestry = NULL;
+	int nr = 0, alloc = 0;

Minor, but please use size_t for allocation variables.

+	int i;

Technically this probably ought to be a size_t as well, but I'm much
more concerned about the allocation ones, where we might accidentally
overflow and underallocate a buffer. Overflowing "i" would probably just
lead to an error or bad result.

I _think_ what the patch is actually doing makes sense (taking as an
assumption that it's heading in a useful direction for the end of the
series).

-Peff