This is the FreeBSD homepage for Jonathan Lemon, containing various
bits and pieces that are somewhat out of date. I also have
another home page which
is also updated irregularly.
This is a copy of the
that was presented at the USENIX BSDCon 2002 conference in San Francisco, CA.
It details the implementation in FreeBSD 4.4 and -current systems, as
well as various performance measurements.
At the BSDCon 2000 conference in Monterey, CA, I gave a talk about
the new kqueue/kevent system in FreeBSD. You can read the paper
that I presented (in
pdf format), or see an
from the presentation.
A similar paper was also published at the the Freenix track of
the USENIX 2001 Technical conference in Boston, MA.
Allow offloading of the TCP/UDP/IP checksums to the hardware, if the
hardware supports it. Currently, only the Alteon driver has been
modified to do delayed checksums.
TCP Timer patch
There is also a short document which outlines
the API used between the FreeBSD kernel and the network driver.
The patch was committed to 5.0-CURRENT on 3/27/2000.
This patch against
-current as of 26-aug-99
-stable as of 07-aug-99
does the following:
Please read the top of the patchfile for various warnings and caveats.
- eliminates the fast/slow timeout lists for TCP and instead
uses a callout entry for each timer.
- Increases the TCP timer granularity to 10ms
- Implements "bad retransmit" recovery, as presented in
"On Estimating End-to-End Network Path Properties", by
Allman and Paxson.