%cpu in system - squid performance in FreeBSD 5.3

[Mohan Srinivasan]

Following up to a mail from Jeff Behl and Sean Chittenden back in Dec.

http://lists.freebsd.org/pipermail/freebsd-net/2004-December/006074.html

>From your description, it looks like moving a kqueue based Squid will 
help considerably (it looks like there is a version of Squid that
is kqueue based - not sure how stable that is though). If you drop a quick 
kernel profile, you will see most of the system CPU being spent in select() 
caused polling of descriptors. In my previous experience with a Squid-based 
proxy several years ago, once you dropped more than a couple of hundred 
connections into select(), CPU utilization spiked sharply because of 
the descriptor polling.

We then hoisted Squid on top of a (homebrew) version of kqueue, which 
caused system CPU to drop dramatically, because all the descriptor polling
was avoided.

mohan