It looks like the freezes could be a separate problem to the CPU spikes. Because these look like input freezes:
[ 6939.689860] shallan gnome-shell[15054]: _clutter_stage_queue_event: assertion 'CLUTTER_IS_STAGE (stage)' failed [ 6939.689984] shallan gnome-shell[15054]: clutter_do_event: Event does not have a stage: discarding. [ 6939.699761] shallan gnome-shell[15054]: _clutter_stage_queue_event: assertion 'CLUTTER_IS_STAGE (stage)' failed [ 6939.699930] shallan gnome-shell[15054]: clutter_do_event: Event does not have a stage: discarding. [ 6939.729329] shallan gnome-shell[15054]: _clutter_stage_queue_event: assertion 'CLUTTER_IS_STAGE (stage)' failed [ 6939.729490] shallan gnome-shell[15054]: clutter_do_event: Event does not have a stage: discarding. but I don't know how that could cause high CPU. -- 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/1899184 Title: CPU spikes and system hangs from gnome-shell every 5-10 seconds Status in gnome-shell package in Ubuntu: Incomplete Bug description: On a fresh installation of Ubuntu 20.04 with no configuration files changed yet (the "install third-party software" option enabled), installed from the official daily ISO, the system freezes for about a second every 5-10 seconds and I see a spike to 70% or more CPU usage by gnome-shell. I cannot see anything that shows up in `sudo journalctl -ef` or `sudo dmesg -w` when the freezes occur. The problem reproduces on both X11 and Wayland, although under Wayland it's more annoying since a freeze leads to repeated keypresses of whatever key was being held down on the keyboard at the time of the freeze. This problem seems to have been reported at <https://www.reddit.com/r/pop_os/comments/gwfn7l/gnome_shell_random_cpu_spikes_every_10_seconds/> but with no plausible resolution or workaround in sight. I tried to follow <https://superuser.com/q/1046603> to figure out what was going on with gnome-shell, but I don't think the results seem very helpful. Result of `sudo perf top`: 4.39% libglib-2.0.so.0.6400.3 [.] g_variant_serialised_n_children 4.26% libc-2.31.so [.] __vfprintf_internal And `sudo perf top --sort comm,dso`: 45.28% gnome-shell libglib-2.0.so.0.6400.3 17.23% gnome-shell libc-2.31.so And `sudo perf record -g -p PID` for the `gnome-shell` PID: + 39.81% 0.01% [unknown] [.] 0000000000000000 + 14.26% 2.04% libc-2.31.so [.] __vasprintf_internal + 8.61% 8.42% libglib-2.0.so.0.6400.3 [.] g_variant_serialised_n_children + 8.51% 8.09% libc-2.31.so [.] __vfprintf_internal And `strace -c -p PID`: % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 34.41 0.128602 5 22784 19837 recvmsg 25.74 0.096215 7 13716 632 ioctl 18.04 0.067420 10 6686 poll 9.50 0.035523 7 4858 write 4.56 0.017025 7 2322 writev ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: gnome-shell 3.36.4-1ubuntu1~20.04.2 ProcVersionSignature: Ubuntu 5.4.0-49.53-generic 5.4.65 Uname: Linux 5.4.0-49-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.10 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Fri Oct 9 07:54:43 2020 DisplayManager: gdm3 InstallationDate: Installed on 2020-10-09 (0 days ago) InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20201007) ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/usr/bin/zsh RelatedPackageVersions: mutter-common 3.36.6-1ubuntu0.20.04.2 SourcePackage: gnome-shell UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1899184/+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
