Gnome shell and Xorg use at least 10% CPU

[Omar Bahareth]

Related to Issue #1773959

On a fresh install of Ubuntu 19.04 on a 2019 Dell XPS 13, I have very high CPU usage from gnome-shell and Xorg (each one is taking up around 10%) when no other process is running. This increased greatly to more than 20% for gnome-shell when I enabled showing seconds in the top bar. After disabling seconds, I went back to ~10% cpu usage for each of those processes again. I opened this because most of the other relevant issues are closed, expired, or marked as invalid.
---
ProblemType: Bug
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
CurrentDesktop: Unity
DisplayManager: gdm3
DistroRelease: Ubuntu 19.04
InstallationDate: Installed on 2019-05-13 (1 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
Package: gnome-shell 3.32.0+git20190410-1ubuntu1
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Tags: disco
Uname: Linux 5.0.0-13-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip docker input lpadmin plugdev sambashare sudo
_MarkForUpload: True

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

Please run this command to send us more information about your machine:

  apport-collect 1828967

[Omar Bahareth (obahareth)]

apport information

[Omar Bahareth (obahareth)]

apport information

[Omar Bahareth (obahareth)]

apport information

[Omar Bahareth (obahareth)]

apport information

[Daniel van Vugt (vanvugt)]

Thanks.

In my experience 10% or so CPU on an i7 is normal. Not ideal, but normal.

Can you please detail what you are doing at the time when gnome-shell uses 10% CPU?

[Daniel van Vugt (vanvugt)]

Please also (while logged into Gnome Shell):

1. Run:

   xrandr > xrandr.txt

   and send us the file 'xrandr.txt'.

2. Run:

   dmesg > dmesg.txt

   and send us the file 'dmesg.txt'.

3. Run:

   lspci -k > lspcik.txt

   and send us the file 'lspcik.txt'.

4. Run:

   journalctl -b0 > journal.txt

   and send us the file 'journal.txt'.

[Omar Bahareth (obahareth)]

xrandr.txt

[Omar Bahareth (obahareth)]

dmesg.txt

[Omar Bahareth (obahareth)]

lspcik.txt

[Omar Bahareth (obahareth)]

journal.txt

[Omar Bahareth (obahareth)]

So this issue is happening when I have a single Chrome tab open (on this issue page) and nothing else. The usage does spike up to higher than 25% for a couple of seconds then back down to 10%-ish (one for Xorg and one for Gnome shell, so 20% on average). My laptop fans spin quite loudly too. I thought it might have been because I was trying a new GTK theme, but I went back to Yaru dark and I still see the same issue.

[Omar Bahareth (obahareth)]

This is what I regularly see in the system monitor.

[Daniel van Vugt (vanvugt)]

Thanks. You have just described bug 1808002 and bug 1773502 so I am marking this as a duplicate of one of them.

[Omar Bahareth (obahareth)]

I'm not so sure it's the same as the other two, I'll run another test tonight. Can you recommend any other app to try? Firefox maybe?

[Daniel van Vugt (vanvugt)]

A different app causing high CPU in gnome-shell would be a different bug. Each app is different due to differing rendering methods.

High CPU in gnome-shell caused by Firefox would be bug 1696305. But you said the problem happens for you with Chrome (comment #12, bug 1808002), or with the system monitor (comment #13, bug 1773502).

[Daniel van Vugt (vanvugt)]

I would expect high CPU in general on your laptop because you are using 3840x2160 and gnome-shell is not yet very efficient.

Please use the above bugs, and/or keep an eye on all the work being done to improve it:

https://trello.com/c/pe5mRmx7

[Omar Bahareth (obahareth)]

I know this is slightly getting off-topic but is there anything other than gnome-shell you would recommend that I can use for the time being?

[Daniel van Vugt (vanvugt)]

You may find the old Ubuntu Unity desktop more efficient. You can install it as a login option with:

  sudo apt install unity-session