🚀 go-pugleaf

hunter@work.nlm.nih.gov (Larry Hunter) writes:
 > Using emacs 18.57 on a Silicon Graphics running IRIX 4.0.4:
 > 
 > I rarely exit emacs, often keeping sessions going for many days at a time.  And
 > I edit large files pretty regularly.  Sometimes, usually when working on a
 > large file in an emacs that has been running for a long time, emacs gets into a
 > state where no matter what I do, I get a minibuffer message that says: "Back to
 > top level".

Stock Emacs has virtual memorty limit of 8 MB.  It is very easy
to exceed this limit if you keep a session going for days.  If
you're lucky, when this happens Emacs will get try to write its
text segment, get a SIGSEGV and die, autosaving most if noit all
of your work.  If you're unlucky Emacs will trash some of its
internal structures, continuing to run and emasculate itself for
some time before dying.

 > [...]
 > I can't put together a short way of recreating this problem, alas. Any idea
 > what causes it?  Any way I could get some warning or prevent it from happening?
 > Thanks for any suggestions....

Rebuild Emacs using Zubkoff's modification that raises the VM
limit to 32 MB, i.e. putting 

#define VALBITS 26
#define GCTYPEBITS 5

in src/config.h

See the question 63 in part 2 of the FAQ posting for this gorup
for more information.