processes stuck in kqread

[kevin kramer]

I have been having issues for some time on -CURRENT. My latest update 
was 7/11. I have identified these processes as being stuck in kqread 
while waiting for them to continue.

Processes that I know are a problem:
sshd - I can watch a login and the process goes from Select to kqread, 
takes about 3-4 minutes to get a login prompt
top - takes about 2-3 minutes to come up
tar - never really even starts to read data in and stays in kqread

Processes not affected:
scp
gstat
cvsup
make

This machine is running AMD64 GENERIC kernel on a Dual-Core Xeons.
dmesg.txt and top-trace.txt here, http://users.centtech.com/~kramer/snapshot

What do I do to debug this?