I just realized that another performance issue I had is actually caused by this
bug.  This occurs with kernel 3.10.0-229.1.2.el7.centos.plus (and probably all
kernels).  After I suspend/resume scrolling in gnome-terminal is very slow. 
For example if I 'cat /var/log/messages' then scrolling in gnome-terminal is
very jerky.  Likewise scrolling from within vi or less (/var/log/messages is a
good way to test) is also painfully slow.  Booting with "radeon.dpm=0" also
solves this gnome-terminal scroll problem for me.