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authorMatthew Wilcox <willy@linux.intel.com>2016-12-14 15:08:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:10 -0800
commit175542f575723e43f897ddb09d0011c13f7cf0ec (patch)
treec9373e49ab8636db5a48f7017f4e942486acf1ef /tools/testing
parentradix-tree: delete radix_tree_range_tag_if_tagged() (diff)
downloadlinux-dev-175542f575723e43f897ddb09d0011c13f7cf0ec.tar.xz
linux-dev-175542f575723e43f897ddb09d0011c13f7cf0ec.zip
radix-tree: add radix_tree_join
This new function allows for the replacement of many smaller entries in the radix tree with one larger multiorder entry. From the point of view of an RCU walker, they may see a mixture of the smaller entries and the large entry during the same walk, but they will never see NULL for an index which was populated before the join. Link: http://lkml.kernel.org/r/1480369871-5271-58-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--tools/testing/radix-tree/multiorder.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 86daf23b3509..c9f656cf5f52 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -332,6 +332,63 @@ void multiorder_tagged_iteration(void)
item_kill_tree(&tree);
}
+static void __multiorder_join(unsigned long index,
+ unsigned order1, unsigned order2)
+{
+ unsigned long loc;
+ void *item, *item2 = item_create(index + 1, order1);
+ RADIX_TREE(tree, GFP_KERNEL);
+
+ item_insert_order(&tree, index, order2);
+ item = radix_tree_lookup(&tree, index);
+ radix_tree_join(&tree, index + 1, order1, item2);
+ loc = find_item(&tree, item);
+ if (loc == -1)
+ free(item);
+ item = radix_tree_lookup(&tree, index + 1);
+ assert(item == item2);
+ item_kill_tree(&tree);
+}
+
+static void __multiorder_join2(unsigned order1, unsigned order2)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ struct radix_tree_node *node;
+ void *item1 = item_create(0, order1);
+ void *item2;
+
+ item_insert_order(&tree, 0, order2);
+ radix_tree_insert(&tree, 1 << order2, (void *)0x12UL);
+ item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
+ assert(item2 == (void *)0x12UL);
+ assert(node->exceptional == 1);
+
+ radix_tree_join(&tree, 0, order1, item1);
+ item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
+ assert(item2 == item1);
+ assert(node->exceptional == 0);
+ item_kill_tree(&tree);
+}
+
+static void multiorder_join(void)
+{
+ int i, j, idx;
+
+ for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
+ for (i = 1; i < 15; i++) {
+ for (j = 0; j < i; j++) {
+ __multiorder_join(idx, i, j);
+ }
+ }
+ }
+
+ for (i = 1; i < 15; i++) {
+ for (j = 0; j < i; j++) {
+ __multiorder_join2(i, j);
+ }
+ }
+}
+
void multiorder_checks(void)
{
int i;
@@ -349,4 +406,5 @@ void multiorder_checks(void)
multiorder_tag_tests();
multiorder_iteration();
multiorder_tagged_iteration();
+ multiorder_join();
}