Change top's notion of idle processes / threads

Right now, when top is set to not display idle processes or threads, it only 
displays processes or threads that are currently in a runnable state or have a 
non-zero %cpu.  However, our %cpu is quite imprecise.  I have patch to change 
top to instead compare the thread or processes runtime (ki_runtime in 
kinfo_proc) against the runtime of the thread or process the last time data 
was fetched.  In essence, top will consider any thread that has run on a CPU 
since the last update as non-idle.  The end result is that mostly-idle threads 
and processes will now be visible in top's idle display.  Personally, I find 
this more useful (and find the current implementation completely useless).  
The patch is at http://people.freebsd.org/~jhb/patches/top_idle.patch

Comments?

-- 
John Baldwin