poor performance when moving windows

Description of problem:
cpu consumption spikes when moving around windows

Version-Release number of selected component (if applicable):
7.8 GA

How reproducible:
100% by customer

Steps to Reproduce:
1. Install RHEL on a system with a Nvidia GPU
2. Install Nvidia proprietary driver
3. Drag a window around
4. observe CPU consumption

Actual results:

• 70%+ cpu consumption

Expected results:

• very low CPU usage

Additional info:

• persists after patch for bz1737515