What's the most efficient method of implementing an infinite parallax background?

In my 2d platformer, I've already implemented a parallax effect in the background by offsetting the bg images from the camera. Because of this, the background elements quickly slide out of view. I was wondering how I could have the background infinitely generate in the most efficient way possible.

I tested out adding 3 copies of the bg elements side by side and having the ones out of view to move to the other side of the screen to simulate infinite background. However, I've noticed some performance issues with this approach, so I am asking if there is a better way to do this.