[Matlab-emacs-discuss] matlab-shell slows down when buffer is large

[Ondra K. <ond...@gm...>]

Eric and others,

I have been a happy user of matlab-shell for years. Thanks Eric.

However, recently (I cannot recollect exactly when, one year ago?), I
experience slowing down of matlab-shell. We run complex matlab programs
which call various external programs. The output displayed in matlab-shell
consists of messages of various format from matlab, latex, svn, rational
expectations solvers, etc. It seems that if there is a lot of output in the
matlab-shell buffer, emacs becomes unresponsive, or very slow. Looking at
top output, emacs seems to take much of processor time doing effectively
nothing. The situation seems to be worse, if there are some matlab errors in
the output.

It seems to me that emacs does some processing of the whole buffer each time
something happens on the command line. When the buffer gets large (say 20000
lines), emacs seems very busy (by processing the whole buffer?) and the
interactive work becomes a real pain. If one executes the code in M-file
using C-c r, it takes ages before the code is copied to the buffer and one
can actually observe how the code is being added character by
c-h-a-r-a-c-t-e-r.

If you tell me how I can debug it, I will be happy to replicate the
behaviour and send you a further information.

I use matlab 2009b, various computers with fedora 12 through 14, emacs
version 23.2.1 or 23.1.1, matlab-shell version 3.3.1 or 3.3.0. My colleague
has the same problem on some ubuntu with newer matlab. On my fedora 12,
emacs 23.1.1 and matlab shell 3.3.1 laptop, I do not experience the problem.
On my desktop with the same versions I have the problem. The only difference
I am aware of is that the laptop is 64, desktop is 32. But my other desktop
is 64 and I have the error there.

I will be happy to provide you with more information if I know what.

Thanks!

Ondra K.