lib/rbtree,drm/mm: add rbtree_replace_node_cached()
Add a variant of rbtree_replace_node() that maintains the leftmost cache
of struct rbtree_root_cached when replacing nodes within the rbtree.
As drm_mm is the only rb_replace_node() being used on an interval tree,
the mistake looks fairly self-contained. Furthermore the only user of
drm_mm_replace_node() is its testsuite...
Testcase: igt/drm_mm/replace
Link: http://lkml.kernel.org/r/20171122100729.3742-1-chris@chris-wilson.co.uk
Link: https://patchwork.freedesktop.org/patch/msgid/20171109212435.9265-1-chris@chris-wilson.co.uk
Fixes: f808c13fd373 ("lib/interval_tree: fast overlap detection")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/rbtree.c b/lib/rbtree.c
index ba4a9d1..d3ff682 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -603,6 +603,16 @@
}
EXPORT_SYMBOL(rb_replace_node);
+void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
+ struct rb_root_cached *root)
+{
+ rb_replace_node(victim, new, &root->rb_root);
+
+ if (root->rb_leftmost == victim)
+ root->rb_leftmost = new;
+}
+EXPORT_SYMBOL(rb_replace_node_cached);
+
void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
struct rb_root *root)
{