diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8798fa029ebeb..d68ee91c00fce 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8683,7 +8683,13 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 			parent = 0;
 		}
 
-		if (need_account) {
+		/*
+		 * Reloc tree doesn't contribute to qgroup numbers, and we have
+		 * already accounted them at merge time (replace_path),
+		 * thus we could skip expensive subtree trace here.
+		 */
+		if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
+		    need_account) {
 			ret = btrfs_qgroup_trace_subtree(trans, next,
 							 generation, level - 1);
 			if (ret) {