[Bug 1691716] Re: High CPU after update-manager is finished, dialog still open

[Brain]

I can confirm exactly the same issue.

The Ubuntu Software Updater exhibits constant high CPU usage when the
final pop-up "The software on this computer is up to date. [ OK ]" is
shown after the updates have been performed.

Output of top:

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                                                                                                                                
 1496 root      20   0  894152 337872 298496 S  13.3  2.1   5:15.88 Xorg                                                                                                                                                                                                                   
 2462 brain     20   0 1577620 153740  71320 S  13.3  1.0   7:51.93 compiz                                                                                                                                                                                                                 
13959 brain     30  10  814320 210292 135388 S  13.3  1.3   1:44.40 update-manager                                                                                                                                                                                                         

There is no reason for high CPU usage just to show a pop-up notification
with an OK button, waiting for user confirmation. It should not need any
CPU in an event driven system.

The high CPU usage disappears after clicking the OK button.

This is particularly a problem when running on battery. The pop-up
dialog usually ends up below other windows and the user doesn't notice
it. In the meantime it is heavily draining the battery.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to update-manager in Ubuntu.
https://bugs.launchpad.net/bugs/1691716

Title:
  High CPU after update-manager is finished, dialog still open

Status in update-manager package in Ubuntu:
  Confirmed

Bug description:
  After update-manager is finished updating the machine, a dialog is
  open `The software on this computer is up to date`

  Until I manually close the dialog, CPU usage is high (causing fan
  activity on my laptop), on an idle laptop.

   1073 root      20   0  327616  52508  21344 S  28,5  1,3  24:13.48 Xorg                                       
   7232 user       20   0 1144896  85272  36848 S  25,2  2,2  19:31.46 compiz                                     
  19863 user       30  10  793744 148616  78720 R  18,5  3,8  17:35.43 update-manager 

  I do wonder why the 3 processes take so much CPU usage, a simple
  dialog waiting for user input could do with less, I suppose.

  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: update-manager 1:16.04.6
  ProcVersionSignature: Ubuntu 4.8.0-52.55~16.04.1-generic 4.8.17
  Uname: Linux 4.8.0-52-generic x86_64
  ApportVersion: 2.20.1-0ubuntu2.5
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Thu May 18 11:45:39 2017
  GsettingsChanges:
   b'com.ubuntu.update-manager' b'show-details' b'true'
   b'com.ubuntu.update-manager' b'window-height' b'691'
   b'com.ubuntu.update-manager' b'first-run' b'false'
   b'com.ubuntu.update-manager' b'window-width' b'754'
   b'com.ubuntu.update-manager' b'launch-time' b'int64 1495095095'
  InstallationDate: Installed on 2014-04-18 (1125 days ago)
  InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
  PackageArchitecture: all
  SourcePackage: update-manager
  UpgradeStatus: Upgraded to xenial on 2016-04-22 (390 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1691716/+subscriptions