On Sep 11, 2015, at 11:23 AM, Warner Losh <imp
at bsdimp.com> wrote:
On Fri, Sep 11, 2015 at 9:03 AM, Paul Koning <paulkoning at comcast.net> wrote:
...
For efficient overlays, RT-11 with Link tends to be better. It's less
flexible but that reduced flexibility enforces more care in overlay design,
and the implementation is a whole lot faster.
True. We were running under RSTS-E and so had some more flexibility.
However, by the time we got to this overlay structure, we knew we'd done
something horribly wrong and spent several weeks slimming down the program,
reducing the number of parameters to some routines and redesigning some
code to have either simpler algorithms, or inlining some code. We slimmed
it by 30% but more importantly went from about 8 overlay depth to 3. Still
slow, but it was acceptably slow rather than insane.
The nice thing about RSTS/E is that you can use either the RT11 or the RSX tools,
according to which is the best answer for what you're doing. And that gives you a
choice of overlay schemes (regions with LINK, or trees with TKB).