I see 9% consistently, and as with those above, clock_gettime seems to be the culprit:
pat@wopr:~$ sudo strace -c -p 29333 [sudo] password for pat: strace: Process 29333 attached ^Cstrace: Process 29333 detached % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 83.37 2.716542 2 1494072 clock_gettime 3.62 0.117823 32 3654 ioctl 3.40 0.110891 3 40996 36714 recvmsg 2.53 0.082418 6 13709 poll [...] Ubuntu 18.04, i7 4.0GHZ, 32GB RAM uname -a: Linux wopr 4.15.0-42-generic #45-Ubuntu SMP Thu Nov 15 19:32:57 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1773959 Title: High CPU usage by gnome-shell when only running gnome-terminal Status in gnome-shell package in Ubuntu: Incomplete Bug description: Even when doing nothing but displaying a terminal screen with top running gnome-shell uses 10% of a CPU. That seems excessive. I disabled all extensions to try and make the test fair. Enabling the system monitor extension increases the load to 13-14%. It seems that the gnome-shell screen painting is highly CPU consuming even if screen updates are infrequent (1 a second for all these cases). ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gnome-shell 3.28.1-0ubuntu2 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Tue May 29 11:38:05 2018 DisplayManager: gdm3 InstallationDate: Installed on 2016-10-27 (578 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) SourcePackage: gnome-shell UpgradeStatus: Upgraded to bionic on 2018-05-19 (9 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1773959/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp