X11 forwarding slows down Ubuntu 16.04 with Unity desktop whose whole graphic interface (including mouse pointer) repeatedly becomes unresponsive for seconds if `ssh -X` or `ssh -X -C` is used. The symptoms are the same as if the system were using slow swap space which isn't the case (verified with `htop` in another tty which can still be changed). This wasn't the case in previous unknown versions.
experienced with client versions 1:6.9p1-2ubuntu0.1 on Ubuntu 15.10, V_7_1_P1-171-g4c6cb83 source installation and 1:7.2p2-4 on Ubuntu 16.04 with `openssh-server` 1:7.2p2-4 on Ubuntu 16.04 on the server side.
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ssh 1:7.2p2-4
Uname: Linux 4.5.0-040500-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Apr 21 12:19:12 2016
InstallationDate: Installed on 2015-12-12 (130 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
SourcePackage: openssh
UpgradeStatus: Upgraded to xenial on 2016-03-14 (37 days ago)
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ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Dependencies:
DistroRelease: Ubuntu 16.04
InstallationDate: Installed on 2015-12-12 (151 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
Package: openssh 20160202-1 [origin: unknown]
PackageArchitecture: amd64
Tags: xenial third-party-packages
Uname: Linux 4.5.2-040502-generic x86_64
UnreportableReason: Das ist kein offizielles Ubuntu-Paket. Bitte entfernen Sie alle Pakete von Drittanbietern und wiederholen Sie den Vorgang.
UpgradeStatus: Upgraded to xenial on 2016-03-14 (58 days ago)
UserGroups: adm autopilot bumblebee cdrom dip libvirtd lpadmin plugdev sambashare sudo
_MarkForUpload: True
apport information