Re: remote X11/GNU emacs/ssh: Incredible slowness loading libs

[Krishnakumar B <kitty@cs.wustl.edu>]

On Monday, 30 September 2002, "David Abrahams" wrote:
> 
> What does "non-native" mean in this context? It certainly is native x86 code
> running on an x86 machine.

I meant the X-server implementation which is the case with any Windows box.

> > like Exceed always has problems related to fonts.
> 
> It's not Exceed, FWIW; it's Cygwin XFree86: http://cygwin.com/xfree/

OK.

> > What terminal are you using ?
> 
> I'm using xterm to launch emacs, but I'm confused by your question because I
> can't see how it's relevant. The slowdowns only occur when emacs isn't
> running in a terminal window.

I will tell you how it hit me. When I run rxvt (comes with Cygwin) and do
this:

local> plink -ssh remote
remote> emacs

I get the same exact slowdowns which you report. But when I open the
terminal application that comes with Putty, and do the same thing, emacs
comes up normally (i.e snappily as if it were running on a local machine).
I don't mess with DISPLAY cruft (anymore) as SSH takes care of doing the
forwarding and setting the DISPLAY correctly.

> Okay. I'm not sure what it means to "switch the SSH client". I have two ways
> of starting ssh:
> 
> 1. From within a dos box running cygwin. It doesn't know about my DISPLAY
> and thus I don't bother with -X

I assume "-X" means ssh -X which requests forwarding of X display ? You
don't need to mess with DISPLAY if your SSH is setup correctly.

> 2. From within an xterm window I launch on my local machine from within TWM
> under cygwin/XFree86

I have never tried that. I would probably be happy with a rootless X server
on Windows as I have no intention of running TWM or such under Windows.
Does rootless X  work under Cygwin XFree86 ? 

> > What does "outside" mean ?
> 
> Outside means I pick the "Cygwin Bash Shell" from my start menu and get a
> "dos box" running bash, with no X server running. When I launch emacs it's
> running in a character-based mode.

OK.

> > It's the command-line utility that ships with Putty.
> 
> If you have slowdowns with plink, why do you think I'll see an improvement
> by switching to its terminal window?

I have no idea. But it works for me. I haven't spent time on figuring out
why. My guess was that with the terminal window I have specified a lot more
setting related to the terminal type and compression, SSH algorithm etc,
remote forwarding etc which might make a difference in the speed. And none
of which I could specify using just plink.

> Uhhhm. Coming up with the correct DISPLAY variable setting for the remote
> machine is difficult, isn't it?

Nope, it is not difficult. See above. Frankly I just don't bother with
DISPLAY anymore. You just need a X server running on your windows box
either Cygwin or Exceed. If you run Cygwin, I think starting an Emacs from
a dos terminal with X forwarding set up should open up the Emacs window
in your XFree86 window.

> Well, OK, I tried it. And it made... no perceivable difference :(
> 
> > Again it's up to you. If you have the time, I am sure that the GNU Emacs
> > developers will appreciate the extra information.
> 
> Do you know where I can find a Cygwin version of this tool (or the
> equivalent)?

Try getting the source and compiling it under Cygwin. I think there is a
version that comes with Windows too. Try this link:

http://windump.polito.it/

I haven't tried it. But unless you are a X guru (I am not), I don't think
the output will make much sense except maybe give you a cue the ports
attracting traffic which in the case is obvious.

-kitty.