On Saturday, January 20, 2018, Warren Toomey <wkt@tuhs.org> wrote:
On Sat, Jan 20, 2018 at 11:11:24AM -0700, Warner Losh wrote:
For a presentation I'm doing this summer on FreeBSD, I thought it would
be cool to get the kernel sizes for various old flavors of Unix. I see
numbers for v5, v6 and v7 in the tuhs tree view, and it appears these
versions are complete enough for me to extract the kernels themselves.
However, I see nothing prior to that.
Github has this project: https://github.com/DoctorWkt/unix-jun72
with a June 1972 Unix kernel. Doing a "make", the generated build/unix is:
-rwxrwxrwx 1 wkt wkt 36432 Jan 21 10:10 build/unix
but I don't have a PDP-11 "size" command to give details.
http://www.tuhs.org/Archive/Distributions/Research/Dennis_v3/ has a Unix
system written in C, timestamped August 31, 1973 (just before Fourth Edition).
Inside nsys.tar.gz you will find:
-rw-r--r-- 0/0 26820 1973-09-24 03:41 u
which is the kernel image.
Unfortunately, we don't have a kernel from 1st Edition or 4th Edition.
Comparing size of kernels is cool and fun, but IMHO comparing system calls is a more valuable metric as to measure the kernel bloat.
It would be interesting to compare number of implemented system calls in various UNIX operating systems along with those kernel sizes, e.g., V7 had around 50 system calls, current FreeBSD and Linux have more than 500...
--Andy