Shared system routines

[M Terribile]

There is one reason for not putting a shared library system on an OS.
It is vary hard to do it in a way that is both general and right without
sacrificing machine cycles, IO bandwidth, or something else.

I have seen it done efficiently, but in a very specific way, to help
maintain speed of a UNI*X machine dedicated to a few special applications.
I have seen it done generally, on the HP 3000, with HARDWARE SUPPORT.  As
a result, loading the COBOL compiler can take up over 3 seconds of dedicated
disk usage (run-time linking).  It IS possible to get around it; the HP's
OS has a ``sticky-bit'' type of facility; but the problem affects EVERYTHING
that runs on the machine and the difference between a dog of a machine and
a smooth--running one lies almost entirely in the technical savvy of the
system administrators.  Not desireable!

Perhaps a middle ground could be found in a multi-kernelized system, with
an efficient ``sys call'' facility, but if you are talking about cheap
machines (managers DO buy DG machines, you know) it may take a while
to happen.

						Mark Terribile
						Duke of deNet