[PATCH v2 20/29] radix tree test suite: multi-order iteration test

Matthew Wilcox
2016-04-14T14:21:51Z

From: Ross Zwisler <ross.zwisler@linux.intel.com>

Add a unit test to verify that we can iterate over multi-order entries
properly via a radix_tree_for_each_slot() loop.

This was done with a single, somewhat complicated configuration that was
meant to test many of the various corner cases having to do with
multi-order entries:

- An iteration could begin at a sibling entry, and we need to return the
canonical entry.
- We could have entries of various orders in the same slots[] array.
- We could have multi-order entries at a nonzero height, followed by
indirect pointers to more radix tree nodes later in that same slots[]
array.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
tools/testing/radix-tree/multiorder.c | 92 +++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)

diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 0a311a5..ba27fe0 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -92,6 +92,96 @@ static void multiorder_insert_bug(void)
item_kill_tree(&tree);
}

+void multiorder_iteration(void)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ struct radix_tree_iter iter;
+ void **slot;
+ int i, err;
+
+ printf("Multiorder iteration test\n");
+
+#define NUM_ENTRIES 11
+ int index[NUM_ENTRIES] = {0, 2, 4, 8, 16, 32, 34, 36, 64, 72, 128};
+ int order[NUM_ENTRIES] = {1, 1, 2, 3, 4, 1, 0, 1, 3, 0, 7};
+
+ for (i = 0; i < NUM_ENTRIES; i++) {
+ err = item_insert_order(&tree, index[i], order[i]);
+ assert(!err);
+ }
+
+ i = 0;
+ /* start from index 1 to verify we find the multi-order entry at 0 */
+ radix_tree_for_each_slot(slot, &tree, &iter, 1) {
+ int height = order[i] / RADIX_TREE_MAP_SHIFT;
+ int shift = height * RADIX_TREE_MAP_SHIFT;
+
+ assert(iter.index == index[i]);
+ assert(iter.shift == shift);
+ i++;
+ }
+
+ /*
+ * Now iterate through the tree starting at an elevated multi-order
+ * entry, beginning at an index in the middle of the range.
+ */
+ i = 8;
+ radix_tree_for_each_slot(slot, &tree, &iter, 70) {
+ int height = order[i] / RADIX_TREE_MAP_SHIFT;
+ int shift = height * RADIX_TREE_MAP_SHIFT;
+
+ assert(iter.index == index[i]);
+ assert(iter.shift == shift);
+ i++;
+ }
+
+ item_kill_tree(&tree);
+}
+
+void multiorder_tagged_iteration(void)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ struct radix_tree_iter iter;
+ void **slot;
+ int i;
+
+ printf("Multiorder tagged iteration test\n");
+
+#define MT_NUM_ENTRIES 9
+ int index[MT_NUM_ENTRIES] = {0, 2, 4, 16, 32, 40, 64, 72, 128};
+ int order[MT_NUM_ENTRIES] = {1, 0, 2, 4, 3, 1, 3, 0, 7};
+
+#define TAG_ENTRIES 7
+ int tag_index[TAG_ENTRIES] = {0, 4, 16, 40, 64, 72, 128};
+
+ for (i = 0; i < MT_NUM_ENTRIES; i++)
+ assert(!item_insert_order(&tree, index[i], order[i]));
+
+ assert(!radix_tree_tagged(&tree, 1));
+
+ for (i = 0; i < TAG_ENTRIES; i++)
+ assert(radix_tree_tag_set(&tree, tag_index[i], 1));
+
+ i = 0;
+ /* start from index 1 to verify we find the multi-order entry at 0 */
+ radix_tree_for_each_tagged(slot, &tree, &iter, 1, 1) {
+ assert(iter.index == tag_index[i]);
+ i++;
+ }
+
+ /*
+ * Now iterate through the tree starting at an elevated multi-order
+ * entry, beginning at an index in the middle of the range.
+ */
+ i = 4;
+ radix_tree_for_each_slot(slot, &tree, &iter, 70) {
+ assert(iter.index == tag_index[i]);
+ i++;
+ }
+
+ item_kill_tree(&tree);
+}
+
void multiorder_checks(void)
{
int i;
@@ -106,4 +196,6 @@ void multiorder_checks(void)
multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i);

multiorder_insert_bug();
+ multiorder_iteration();
+ multiorder_tagged_iteration();
}
--
2.8.0.rc3