Testcase 01
-----------

This test attempts to verify that when a CPU is offlined, that a process
writing to disk doesn't cause an issue.  We create a process that writes
to disk, force it to run only on a specified CPU by setting its CPU
affinity to just that CPU, then offline that CPU, and verify that the
process moves to another processor properly.


Notes
=====

There are two kinds of masks:  One to specify which CPU's are allowed
to be used for the given process, and one for the smp affinity.

This may be hard to verify but we can indirectly check on this
by looking at /proc/stat or measuring the relative performance
of some parallelized benchmark before and after onlining the CPU.


Algorithm
=========
Given a CPU to test that exists

Take a snapshot of what CPUs are on and off initially

Make sure the cpu is online

Start up a process that writes to disk

Loop until done:
  Take a snapshot of /proc/interrupts

  Foreach CPU in the system
    online the CPU
    migrate the IRQs to it
    sleep a little while

  Foreach CPU in the system
    migrate IRQs onto the CPU
    offline the cpu
    sleep a little while

  Take another snapshot of /proc/interrupts

  Print a report showing the change in IRQs


When exiting:
  Kill the write loop process

  Restore all CPUs to their initial state