inappropriate use of nroff-mode leads to grief

[Robert Marshall]

I use logrotate to compress /var/log files so these are saved as (e.g)
syslog.1.gz

When I edit them, I have global-font-lock mode set but
font-lock-maximum-size is set to (the default) 256000 and the current
buffer is 9000000 but font-lock-mode still appears to be on and
whenever I try to scroll around the log file it's trying to parse it
as nroff - not a great success.

Takes forever to page up:

  parse-partial-sexp(1 9649428)
  font-lock-fontify-syntactically-region(9649428 9650100 nil)
  font-lock-default-fontify-region(9649428 9650019 nil)
  font-lock-fontify-region(9649428 9650019)
  run-hook-with-args(font-lock-fontify-region 9649428 9650019)
  jit-lock-fontify-now(9649428 9649928)
  jit-lock-function(9649428)
  scroll-down(nil)

Don't like the look of that parse-partial-sexp ! I realise the real fix is
something like

(add-to-list 'auto-mode-alist '("^/var/log" . fundamental-mode))

 but should anything be parsing 9meg of text for just-in-time hilighting?

R
-- 
Science is to computer science as hydrodynamics is to
plumbing.                       -- Stan Kelly-Bootle