Perhaps more interesting is that in this small sample the CPU usage coincides with some CIFS activity. The low network usage suggests this is some sort of meta operation such as lock fiddling. I would look at a larger sample and, if this correlation remains in a larger sample, I'd look at what was happening with CIFS. Possibly there is some operation which causes the filer to look at a large amount of cached data (accounting for the low cache age as well as CPU usage) without actually transferring much over the wire. It's been a long time since I looked at CIFS, though.
mmm, good point, it could be old bug 11596, only on a smaller scale. i.e. the filer doesn't appear to hang, but the CPU is still taking a hit. this is a pretty serious bug that needs to be handled soon. there is a work around, but what really needs to happen is NetApp needs to take some action to fix this bug, either with something like the options raid.reconstruct_speed or a way to insure all directories are created with CIFS entries as well as NFS.
-steve