Found the architecture notes on Varnish, a high performance caching reverse proxy from Poul-Henning Kamp, a veteran FreeBSD kernel developer. Nice description of ways to use the operating system to your benefit and to minimize the costs of memory management.

And the blog where I found the link to the notes

Alan Dekok (FreeRADIUS chief architect) has been playing around with performace and there’s an ongoing discussion on the mailing list about memory management, so this might prove relevant.