High interrupt count on irq12

[Gardner Bell]

Since I installed -CURRENT, I've noticed irq12 has a rather high
interrupt count for only 29mins of uptime.  Interrupt load appears to
be rather low at only 0.4% so I'm not sure what can be causing the high
count.  Here is the output of vmstat.

dan at home$ vmstat -i
interrupt                          total       rate
irq1: atkbd0                        3011          1
irq12: psm0                       121265         61
irq14: ata0                           58          0
irq19: uhci1+                       5181          2
irq20: fxp0                         1377          0
irq22: pcm0                           11          0
cpu0: timer                      3812581       1923
cpu1: timer                      3812247       1923
Total                            7755731       3913

My kernel is pretty much GENERIC except for the removal of drivers that
I don't use/need, WITNESS, and INVARIANTS.

Gardner