instability in Berkeley versus AT&T releases

[Guy Harris]

> > By implication that puts all commercial vendors of 4.2BSD systems
> > in the "unstable computing environment business"?
> 
> Judging by how often we find bugs and our machines crash, I'd say yes,
> runnning 4.2 BSD is being in an unstable computing environment.

John didn't say "by implication that says 4.2BSD is an unstable computing
environment", he said "by implication that puts all *commercial* vendors of
4.2BSD systems in the 'unstable computing environment business'."  My
machine is supplied by a "commercial vendor of 4.2BSD systems" (as is
John's, I suspect :-) :-) :-)), and, well,

	4:00pm  up 5 days,  2:33,  6 users,  load average: 0.23, 0.07, 0.00

It's been up longer.  The only times it's crashed due to an OS bug are a few
times when some pre-release software hung and it had to be rebooted (that
problem hasn't recurred, and it wasn't the 4.2BSD base's fault) and once
when it crashed due to some code I'd added (which, for the benefit of those
of you who sneer at "lint", would have been reported by "lint"ing the
kernel).

I've rarely found bugs, and most of them have been pretty small.  (Several
pieces of code from the System V release would have crashed on this machine,
because they dereference null pointers, so the Berkeley people aren't the
only people who ship buggy UNIX software.)

Then again, the "stability" being discussed here is not resistance to
crashes but the absence of system changes that break existing code.  Yes,
4.2BSD has introduced some changes which break existing code.  So has System
V.  (Remember the time they decided to enforce the "only one external
definition" rule?  The old COMMON-block semantics came back faster than Old
Coke...)

	Guy Harris