App grid animation causes heavy CPU spikes and dropped frames in Wayland & Xorg

Upon further investigation, I can confirm that this issue only affects the App Drawer. Minimizing and Maximizing windows, and etc are all buttery smooth.

How about changing screen brightness? The only animation that causes some sluggish behaviors is changing screen brightness (I'm on a laptop). Not sure if this is related or not but worth asking.

Yes, it does. When changing the screen brightness in 17.10, the slider wiggles around rapidly during a slight delay before the brightness actually adjusts.

Well, my case is the opposite: The animation is slow but the adjustment is immediate. Thanks!

Status changed to 'Confirmed' because the bug affects multiple users.

Thanks for the bug report. We are aware of this problem and hope to look at it in detail soon.

I'm now looking at a profile of gnome-shell running normally, next to a profile of the same but with the activities overview open. I can now see at least two causes of the higher CPU (and higher GPU load?) when the overview is open.

Just to clarify, the app drawer has this problem as well.

Yes, thanks for reminding me. I will also check that when I get back to this work.

Forgive me, but what method did you use to profile the resource usage of gnome-shell? I would like to see if the root cause you discovered matches what affects my system.

What I did was profile gnome-shell using sysprof, and I found that file /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.5502.0 uses 25.06% of CPU time by itself. My guess is that it's called/utilized very frequently. Attached is part of the output that should explain what I'm stating.

Let me know if any more information is necessary.

Sorry, I just realised these are indeed two very different bugs.

I am moving to bug 1757088 to focus on the activities overview.

P.S. I also have a patch which should help this bug 1750197 a bit:
https://gitlab.gnome.org/GNOME/mutter/merge_requests/26

P.P.S. Please use only Xorg sessions for now if you need the best performance. Wayland has its own unique performance bottlenecks I will work on later, probably in 18.10:
https://trello.com/c/Q6JYXPPs

Upstream bug:
https://gitlab.gnome.org/GNOME/gnome-shell/issues/55

I very much appreciate the work you have done upstream. I have been trying to follow along, but I cannot contribute to this particular issue due to my skillset. Are the upstream changes going to be seen in 18.10 or the existing 18.04 when finalized?

The upstream bugs related to this issue (found up top) have been updated, as work is being done upstream.

Now in https://gitlab.gnome.org/GNOME/mutter/issues/232

Please keep this old bug open as this is the one other sources are linking to.

Also, no fix has been released yet so it doesn't matter how old this bug is.

Not to be nagging, but I can't help but enjoy this upstream fix as it was implemented in other distros like Fedora. Is there an ETA for Ubuntu's implementation?

Those upstream fixes (https://gitlab.gnome.org/GNOME/gnome-shell/issues/349) were actually authored by Canonical. They will appear in Ubuntu when we ship gnome-shell 3.32 (likely Ubuntu 19.04).

Note however the high CPU (not the animation smoothness) fix (https://gitlab.gnome.org/GNOME/gjs/merge_requests/236) is being backported already, in bug 1803271. In hindsight though I could have used this bug instead...

Also, given how simple the fix for the animation smoothness is (https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/253) then I think yes it would be easy to get that backported to existing Ubuntu releases.

Seems the fix was already backported to gnome-shell 3.30.2, so is in disco already and soon cosmic.

Fix committed to cosmic (see bug 1813350).

Fix released as part of...

gnome-shell (3.30.2-0ubuntu1.18.10.1) cosmic; urgency=medium

  [ Iain Lane ]
  * New upstream release 3.30.2 (LP: #1813350)

  [ Marco Trevisan (Treviño) ]
  * d/p/power-Label-the-PENDING_CHARGE-state-as-Not-Charging.patch:
    - Label the PENDING_CHARGE state as "Not Charging" (LP: #1745032)
  * d/p/ibusManager-Don-t-pass-undefined-callback-to-ibus.patch:
    - Fix missing icon in keyboard indicator (LP: #1812266)

 -- Iain Lane <email address hidden> Fri, 25 Jan 2019 19:04:17 +0000

Found the fix hiding in gnome-shell_3.28.3+git20190124.orig.tar.xz

So it's already in bionic-proposed:

https://launchpad.net/ubuntu/+source/gnome-shell/3.28.3+git20190124-0ubuntu18.04.1

gnome-shell (3.28.3+git20190124-0ubuntu18.04.1) bionic; urgency=medium

  * New git snapshot release up to commit 24cdcc56d (LP: #1811900)
    - Don't fill journal with osdWindow errors (LP: #1772677)
    - Fix missing icon in keyboard indicator (LP: #1812266)
  * d/p/authPrompt-Do-not-enable-sensitivity-if-retries-are-disal.patch,
    d/p/authPrompt-Unset-preemptiveAnswer-on-reset.patch,
    d/p/gdm-util-Always-allow-to-retry-login-in-unlock-mode.patch,
    d/p/ibus-set-content-type-no-holdKeyboard.patch,
    d/p/popupMenu-Don-t-handle-key-presses-directly-if-there-are-.patch,
    d/p/st-button-Ignore-pointer-emulated-touch-events.patch,
    d/p/shell-ignore-invalid-window-monitor-index.patch,
    d/p/workspace-fix-repositioned-windows-in-activities.patch:
    - Removed patches applied upstream
  * d/p/StIcon-only-compute-shadow-pipeline-when-the-texture-is-p.patch,
    d/p/js-fix-invalid-access-errors.patch,
    d/p/js-ui-Choose-some-actors-to-cache-on-the-GPU.patch,
    d/p/optional-hot-corner.patch,
    d/p/st-texture-cache-Cancel-sliced-image-loading-on-target-ac.patch,
    d/p/workaround_crasher_fractional_scaling.patch:
    - Refreshed as per upstream changes
  * d/p/keyboard-Filter-redundant-FocusTracker-position-changed-s.patch,
    d/p/keyboard-Listen-to-IbusPanelService-focus-in-out-to-track.patch:
    - Fix OSK activation on X11 (LP: #1760399)
  * d/p/power-Label-the-PENDING_CHARGE-state-as-Not-Charging.patch:
    - Label the PENDING_CHARGE state as "Not Charging" (LP: #1745032)
  * d/p/debian/patches/volume-Add-back-sound-feedback-on-scroll.patch:
    - Add missing include (LP: #1811908)

 -- Marco Trevisan (Treviño) <email address hidden> Fri, 25 Jan 2019 18:29:40 +0000