bug#40113: 28.0.50; Tramp uses 100% CPU then times out

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Alan Third]

When I try to open "/ssh:warhorse:" Emacs uses 100% CPU and after a minute or
so gives me a timeout error. The buffer *tramp/ssh warhorse* doesn't
exist. Strangely one of my three linux boxes appears to connect OK,
but two time out. I can't see anything different between them.

I can ssh to them OK. I'm using zsh as the shell with the same .zshrc on all
three.

I'm unsure how to debug this problem further.


In GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 Version 10.14.6 (Build 18G3020))
 of 2020-03-16 built on breton.holly.idiocy.org
Repository revision: 9dccaf8a5cdb10dae597345ec3741475477a7d97
Repository branch: master
Windowing system distributor 'Apple', version 10.3.1671
System Description:  Mac OS X 10.14.6

Recent messages:
Auto-saving...done
Auto-saving...done
Auto-saving...done
report-emacs-bug-hook: Wrong type argument: stringp, nil [2 times]
Mark set [2 times]
previous-line: Beginning of buffer [2 times]
scroll-down-command: Beginning of buffer
previous-line: Beginning of buffer
scroll-down-command: Beginning of buffer
Mark set [2 times]

Configured using:
 'configure
 PKG_CONFIG_PATH=/usr/local/opt/libxml2/lib/pkgconfig:/usr/local/opt/libffi/lib/pkgconfig'

Configured features:
RSVG GLIB NOTIFY KQUEUE ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS
MODULES THREADS PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Messages

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(help-mode pp shadow sort mail-extr emacsbug message rmc puny dired
dired-loaddefs rfc822 mml easymenu mml-sec epa derived epg epg-config
gnus-util rmail rmail-loaddefs text-property-search mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils tramp-cmds
tramp-cache tramp-sh tramp tramp-loaddefs trampver tramp-integration
files-x tramp-compat shell pcomplete comint ansi-color ring parse-time
iso8601 time-date ls-lisp format-spec auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs cl-loaddefs cl-lib password-cache json
subr-x map seq byte-opt gv bytecomp byte-compile cconv tooltip eldoc
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/ns-win
ns-win ucs-normalize mule-util term/common-win tool-bar dnd fontset
image regexp-opt fringe tabulated-list replace newcomment text-mode
elisp-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors frame minibuffer cl-generic
cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads kqueue cocoa ns
lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 67324 16837)
 (symbols 48 8141 0)
 (strings 32 24277 2073)
 (string-bytes 1 888909)
 (vectors 16 14087)
 (vector-slots 8 174757 17740)
 (floats 8 42 90)
 (intervals 56 521 54)
 (buffers 1000 16))

-- 
Alan Third

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Michael Albinus]

Alan Third <alan@idiocy.org> writes:

> When I try to open "/ssh:warhorse:" Emacs uses 100% CPU and after a minute or
> so gives me a timeout error. The buffer *tramp/ssh warhorse* doesn't
> exist. Strangely one of my three linux boxes appears to connect OK,
> but two time out. I can't see anything different between them.
>
> I can ssh to them OK. I'm using zsh as the shell with the same .zshrc on all
> three.
>
> I'm unsure how to debug this problem further.

Set tramp-verbose to 6. Show Tramp's debug buffer after the timeout.

Is it possible to interrupt Tramp with C-g?

Best regards, Michael.

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Alan Third]

On Wed, Mar 18, 2020 at 11:52:03AM +0100, Michael Albinus wrote:
> Alan Third <alan@idiocy.org> writes:
> 
> > When I try to open "/ssh:warhorse:" Emacs uses 100% CPU and after a minute or
> > so gives me a timeout error. The buffer *tramp/ssh warhorse* doesn't
> > exist. Strangely one of my three linux boxes appears to connect OK,
> > but two time out. I can't see anything different between them.
> >
> > I can ssh to them OK. I'm using zsh as the shell with the same .zshrc on all
> > three.
> >
> > I'm unsure how to debug this problem further.
> 
> Set tramp-verbose to 6. Show Tramp's debug buffer after the timeout.

The debug buffer has about 150MB of data in it. Even compressed it’s
over 4MB. Should I send it over or is there something specific you
want me to look for?

> Is it possible to interrupt Tramp with C-g?

Yes, it takes a few seconds to react, but it does work.
-- 
Alan Third

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Michael Albinus]

Alan Third <alan@idiocy.org> writes:

Hi Alan,

> The debug buffer has about 150MB of data in it. Even compressed it’s
> over 4MB. Should I send it over or is there something specific you
> want me to look for?

You can send it directly to me. I'll take a look.

>> Is it possible to interrupt Tramp with C-g?
>
> Yes, it takes a few seconds to react, but it does work.

Thanks. Just some other questions: Does it happen also with "emacs -Q"?
Does it happen with Emacs 27.0.90, or Emacs 26.3?

Best regards, Michael.

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Alan Third]

On Wed, Mar 18, 2020 at 09:27:30PM +0100, Michael Albinus wrote:
> Alan Third <alan@idiocy.org> writes:
> 
> Hi Alan,
> 
> > The debug buffer has about 150MB of data in it. Even compressed it’s
> > over 4MB. Should I send it over or is there something specific you
> > want me to look for?
> 
> You can send it directly to me. I'll take a look.

Sent off list.

> >> Is it possible to interrupt Tramp with C-g?
> >
> > Yes, it takes a few seconds to react, but it does work.
> 
> Thanks. Just some other questions: Does it happen also with "emacs -Q"?
> Does it happen with Emacs 27.0.90, or Emacs 26.3?

It happens with both Emacs 27 (just did a pull/make, so it’s up to
date) and the master branch. I’ve not tried 26.

All the testing here is with emacs -Q on the master branch. With my
full configuration it seems even worse as even just typing the path in
can slow down Emacs. I don’t know if that’s related, though.
-- 
Alan Third

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Michael Albinus]

Alan Third <alan@idiocy.org> writes:

Hi Alan,

>> Thanks. Just some other questions: Does it happen also with "emacs -Q"?
>> Does it happen with Emacs 27.0.90, or Emacs 26.3?
>
> It happens with both Emacs 27 (just did a pull/make, so it’s up to
> date) and the master branch. I’ve not tried 26.

That's consistent with the other message I've sent. The problem is not
specific to any Tramp version.

Best regards, Michael.

bug#40113: Fwd: bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Michael Albinus]

[-- Attachment #1: Type: text/plain, Size: 40 bytes --]

Forwarding to the proper email address


[-- Attachment #2: Type: message/rfc822, Size: 2820 bytes --]

From: Michael Albinus <michael.albinus@gmx.de>
To: Alan Third <alan@idiocy.org>
Subject: Re: bug#40113: 28.0.50; Tramp uses 100% CPU then times out
Date: Wed, 18 Mar 2020 21:46:07 +0100

Alan Third <alan@idiocy.org> writes:

Hi Alan,

>> > The debug buffer has about 150MB of data in it. Even compressed its
>> > over 4MB. Should I send it over or is there something specific you
>> > want me to look for?
>>
>> You can send it directly to me. I'll take a look.
>
> Attached. Ill answer your questions on the list.

Thanks.

> 14:53:34.685303 tramp-process-actions (6) #
> Linux warhorse 4.19.0-5-amd64 #1 SMP Debian 4.19.37-3 (2019-05-15) x86_64
>                                                      (__
>                                                     ,_) \_,-/
>  __        __                                     /__      )__,
>  \ \      / /_ _ _ __                             )/  _\_    /
>   \ \ /\ / / _` | '__|                            /d   \ \   \__
>    \ V  V / (_| | |                              /  _.'  /    ( '
>     \_/\_/ \__,_|_|                             (,-,) |  |_   |_,
>                                                 ,-.___|_  /_,  /
>             _   _                               ) .__        ) \
>            | | | | ___  _ __ ___  ___            \ \\`-..-    \(`.
>            | |_| |/ _ \| '__/ __|/ _ \            \( \_\          `._
>            |  _  | (_) | |  \__ \  __/             \`-,'`.           `-.
>            |_| |_|\___/|_|  |___/\___|              `'    `-.__         \
>                                                            `,'      |-,._)
>                                                             !       ,')   `-.
>                                                             (    ,-'  (   ,-.)
>                                                              \   \  \ _/   \_
>                                                               \_ |\_ \`-'._  )
>                                                               ( ,'( /      )/
>                                                           __,','__/(
>                                                          /__(^ 7..1"
> Last login: Wed Mar 18 14:51:35 2020 from 2001:8b0:3f8:8129:d054:844b:876f:607a
> %                                                                               [33;1mwarhorse[0;29m:/home/alan>[?2004h
> 14:53:34.685489 tramp-process-sentinel (5) # Sentinel called: #<process *tramp/ssh warhorse*> killed: 9

> 14:53:34.687594 tramp-process-actions (1) # File error: Timeout reached, see buffer *tramp/ssh warhorse* for details

Looks, like zle (zsh line editor) is active. Could you pls consult the
Tramp manual how to avoid this?

Best regards, Michael.

bug#40113: 28.0.50; Tramp uses 100% CPU then times out

[Alan Third]

On Wed, Mar 18, 2020 at 09:48:44PM +0100, Michael Albinus wrote:
> Alan Third <alan@idiocy.org> writes:
> 
> Hi Alan,
> 
> >> Thanks. Just some other questions: Does it happen also with "emacs -Q"?
> >> Does it happen with Emacs 27.0.90, or Emacs 26.3?
> >
> > It happens with both Emacs 27 (just did a pull/make, so it’s up to
> > date) and the master branch. I’ve not tried 26.
> 
> That's consistent with the other message I've sent. The problem is not
> specific to any Tramp version.

Thank you, Michael. ZLE seems to have been the problem.

I suppose it must be something that’s changed in zsh and my one
working server is rather out of date.

I’ll close this bug report.

-- 
Alan Third