Strange ARC/Swap/CPU on yesterday's -CURRENT

[Justin Hibbits]

Hi Don,

> I initially missed that this was on powerpc.  I believe that arch is a
> bit odd with characters unsigned by default and arithmentic shifts
> always being unsigned.  Things like that could mess up the algorithm,
> but I didn't see anything suspicious in the r329882 diff.

I think the biggest difference for powerpc64 vs amd64 in this case is
the (currently) relatively small KVA (7.5GB vs 2(?) TB).  That might
make a difference regarding VM pageout calculations.

- Justin