The feel of a LispM/List of running machines

Marcus G. Daniels marcus@cathcart.sysc.pdx.edu
01 May 1997 20:23:06 -0700


>>>>> "CWG" == cwg  <cwg@DeepEddy.Com> writes:

CB> Because the UNIX file system is very low level. Think of UFS being
CB> to file systems what Micro kernels are to OSes. It is a low level
DB> facility on which you can build something better.

CWG> Except that it's such a poor low level facility that you can't
CWG> easily build something better on top of it.  We need to start by
CWG> faking what we need on top of Unix file systems with the hope
CWG> that eventually someone (on this list?)  will write a decent file
CWG> system that we can use.

I'm interested in the idea of a Lisp archiving system for free Unix
implementations. 

My intuition is that existing Unix filesystems can, without much
difficulty, enhanced things like ACLs, and object properties (ext2fs
already has support for some of this).  However, I think these improvements,
if made, 1) shouldn't be specific to Lisp and 2) are marginal
improvements anyway; I'm skeptical another filesystem would be that useful.

The big step up I imagine would be a `persistence property' for Lisp
objects.  And of course, this new file^H^H^H^Hobjectsystem ought to be
written in Lisp as much as possible.

Hrmm.  This seems to raise another issue: even with threads for CMUCL,
even with layering LispOS on top of a Unix system or microkernel, an
overriding goal here is to get as much as possible in to one Lisp
address space, right?  If we are pointing all these system services
into one Lisp process, doesn't this mean that we'll run in to
sluggishness without some kind of non-blocking GC?  Perhaps we'd be
better off coming up with a good-performance way to share Lisp objects
across multiple Lisp processes?