Subject: bug#3977: 23.1.50; Tramp slows down Emacs

From: Torsten Bronger <[email-masked]>
Date: Mon, 03 Aug 2009 18:22:09 +0200

Hallöchen!

Michael Albinus writes:

> Torsten Bronger <[email-masked]> writes:
>
> [...]
>
>> When using Emacs locally, you don't see this effect.  However,
>> here at work, I start Emacs on my home machine through an SSH
>> tunnel, and then Tramp slows down Emacs significantly; not Emacs
>> per se but only the display.  For example, I can scroll through a
>> large text file and it needs the same amount of time.  But with
>> Tramp, I don't see the text scrolling, just reaching the end.
>
> Honestly, I cannot reproduce the effect. How do you start Emacs
> through the tunnel? I have done it via
>
> ssh -X otherhost /usr/local/src/emacs/src/emacs -Q

This is equivalent to my test.

And then, I say "M-x customize-group RET RET" and have 4 TCP packets
per second (maybe cursor blinking).  If I start the above command
again and say "M-x customize-group RET tramp RET", I have 60 packets
per second.

> [...]
>
> [...] But as I said, I cannot see a difference in network activity
> with loaded / not loaded Tramp. Could you, please, analyze these
> additional packages in more detail?

Then somebody must tell me how.  ;-)  I'm really not an expert in
packet sniffing.  Those packages are encrypted, so Wireshark shows
me only garbage.

> Which port are they speaking to, which application is behind? Is
> it really X?

I think -X means that only the X port is forwarded.  Besides, the
local machine has nothing else listening.  There is no shared
directory, and no SSH server.

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
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