Add TODO.
diff --git a/writer.go b/writer.go
index aa10c66..51c0a00 100644
--- a/writer.go
+++ b/writer.go
@@ -31,7 +31,7 @@
 	wrap := next - this.ringSize
 
 	if wrap > this.gate {
-		min := this.readerBarrier()
+		min := this.readerBarrier() // TODO: the most expensive call
 		if wrap > min {
 			return Gating
 		}