I decided that it probably wouldn't hose my IceWM if I killed compiz, so I 
killed it.  I was right.  It seems that the system respawned another 
compiz process immediately, but that process was using 0% CPU instead of 
100% CPU.  So that worked.

It probably hosed the desktop in my office, but I didn't feel like going 
to the office to see.  Maybe someday.  I'm enjoying the remote VNC 
approach.

Thanks for all the helpful comments!

Mike


On Mon, 5 Sep 2016, Andrew Lunn wrote:

> On Mon, Sep 05, 2016 at 02:35:01PM -0500, Mike Miller wrote:

>> It looks like compiz is running amok and using 100% CPU.  That might 
>> mean that it is using 100% of one of eight threads, or maybe using all 
>> of one core.
>
> The kernel scheduler will try to keep it on one core. Migrating it from 
> one core to another is inefficient, in that it has hot memory in the L1 
> cache which is local to a core. Moving it means it needs to rebuild 
> that.
>
> http://www.compiz.org/ tells you more about what compiz is.
>
> It might be enough to log out your desktop session and log in again, so 
> it starts a new desktop.