why would I be seeing kswapd0 using so much CPU?

[Kevin Martin]

I'm seeing this:

# top

top - 10:28:30 up 23:45,  9 users,  load average: 0.75, 0.83, 0.98
Tasks: 221 total,   2 running, 219 sleeping,   0 stopped,   0 zombie
%Cpu(s):  1.0 us, 27.5 sy,  0.0 ni, 69.9 id,  0.8 wa,  0.6 hi,  0.2 si,  0.0 st
KiB Mem:   3952540 total,  2834232 used,  1118308 free,     3024 buffers
KiB Swap:  4095996 total,   332780 used,  3763216 free,   163712 cached

  PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND

   41 root      20   0     0    0    0 R  98.0  0.0 262:56.14 kswapd0

I'm not sure why this would be happening since I'm not using all of my memory and the swap used is almost nothing.  It's eating an
entire CPU!

Any thoughts?

Thanks.

Kevin