[Simh] SIMH 3.8-1 IDLE in VMS, interesting CPU usage

[Marc Chametzky]

I'm setting up an ESXi system into which I'm moving my Solaris server, 
and now setting up some ubuntu JeOS virtual systems to host some 
trailing-edge hardware emulations. One nice thing is that I can dedicate 
part of a CPU to the VAX emulator and prioritize it lower, so it can 
spin its wheels appropriately, leaving the overall server available for 
other tasks as needed.

As a test, I turned on IDLE, and I got this very interesting graph: 
http://www.bluevine.net/~marc/CPUidle.jpg

When IDLE is disabled, the CPU usage is a straight line, as it should 
be. I find it quite interesting that with IDLE, it slowly uses more CPU 
until it peaks out at 100% of its allotment, then it drops back down to 
just about 15% and starts climbing again.

Between the two, I prefer the consistency of the straight line, so I'll 
probably disable IDLE again. I just thought this was interesting enough 
to share.

--Marc