[TUHS] Systematic approach to command-line interfaces

[Larry McVoy]

On Tue, Sep 28, 2021 at 10:46:25AM -0700, Greg A. Woods wrote:
> The "unix" nod to
> single level storage by way of mmap() suffers from horribly bad design
> and neglect.

I supported Xerox PARC when they were redoing their OS as a user space
application on SunOS 4.x.  They used mmap() and protections to take
user level page faults.  Yeah, there were bugs but that was ~30 years
ago.

In more recent times, BitKeeper used mmap() and protections to take the
same page faults (we implemented a compressed, XORed file storage that
filled in "pages" on demand, it was a crazy performance improvement)
and that worked on pretty much every Unix we tried it on.  Certainly
worked on Linux first try.

So what is it about mmap you don't like?