rb_remove
int rb_remove(struct rbtree __arena *rbtree, u64 key);
ret = rb_remove(rbtree, key);
ret = rb_remove(rbtree, key);
ret = rb_remove(rbtree, key);
ret = rb_remove(rbtree, prefix + (rmval % numkeys));
rb_remove(rbtree, prefix + i);
ret = rb_remove(rbtree, prefix - (rmval % numkeys));
ret = rb_remove(rbtree, prefix - i);
if (rb_remove(alloc, 0))
if (!rb_remove(noalloc, 0))
ret = rb_remove(rbtree, rbtree->root->key);