[c-nsp] CPU interrupt utilization

[shmapty at foureleven.org]

show proc cpu | in ^C

gives you CPU util for five seconds: XX%/YY%

the percentage after the slash gets added to the sum of the listed
procs' percentages to give the total CPU util percentage.  but,
what exactly is the breakdown/utilization of the percentage after
the slash?

i believe these are not attributable to specific procs, but to cpu
interrupts.  on my 6500/sup2 though the five second util is 50%/35%

router##sho proc cpu | ex 0.0
CPU utilization for five seconds: 52%/36%; one minute: 53%; five minutes: 53%
 PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
  53      316228   1740122        181  1.80%  0.94%  0.92%   0 Compute load avg

  71     4556300  22604419        201 13.17% 15.38% 14.29%   0 IP Input

this seems anomolously high.  how do i go about troubleshooting this?
the cef stats, cache hit percentage, etc appear normal.

thanks.