augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks
for the case where the augmented value is a scalar whose definition
follows a max(f(node)) pattern. This actually covers all present uses of
RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the
various RBCOMPUTE function definitions.
[walken@google.com: fix mm/vmalloc.c]
Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com
[walken@google.com: re-add check to check_augmented()]
Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com
Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index 62b8ee9..41ae3c7 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -77,26 +77,10 @@ static inline void erase_cached(struct test_node *node, struct rb_root_cached *r
}
-static inline u32 augment_recompute(struct test_node *node)
-{
- u32 max = node->val, child_augmented;
- if (node->rb.rb_left) {
- child_augmented = rb_entry(node->rb.rb_left, struct test_node,
- rb)->augmented;
- if (max < child_augmented)
- max = child_augmented;
- }
- if (node->rb.rb_right) {
- child_augmented = rb_entry(node->rb.rb_right, struct test_node,
- rb)->augmented;
- if (max < child_augmented)
- max = child_augmented;
- }
- return max;
-}
+#define NODE_VAL(node) ((node)->val)
-RB_DECLARE_CALLBACKS(static, augment_callbacks, struct test_node, rb,
- u32, augmented, augment_recompute)
+RB_DECLARE_CALLBACKS_MAX(static, augment_callbacks,
+ struct test_node, rb, u32, augmented, NODE_VAL)
static void insert_augmented(struct test_node *node,
struct rb_root_cached *root)
@@ -238,7 +222,20 @@ static void check_augmented(int nr_nodes)
check(nr_nodes);
for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) {
struct test_node *node = rb_entry(rb, struct test_node, rb);
- WARN_ON_ONCE(node->augmented != augment_recompute(node));
+ u32 subtree, max = node->val;
+ if (node->rb.rb_left) {
+ subtree = rb_entry(node->rb.rb_left, struct test_node,
+ rb)->augmented;
+ if (max < subtree)
+ max = subtree;
+ }
+ if (node->rb.rb_right) {
+ subtree = rb_entry(node->rb.rb_right, struct test_node,
+ rb)->augmented;
+ if (max < subtree)
+ max = subtree;
+ }
+ WARN_ON_ONCE(node->augmented != max);
}
}