Pop-ups causing short freezes on Xorg with nvidia

(I repost it from fedoraforum.org, since I am not sure if it Fedora/Xorg/Gnome/nvidia problem)

Hello,

I am running an optimus laptop with nvidia GeForce GTX 1060/PCIe/SSE2 on nvidia proprietary drivers, with external HDMI monitor connected (HDMI directly connected to nvidia thus the need for nvidia driver).

I’ve recently upgraded from Fedora 25 to Fedora 27, running Gnome 3. This upgrade required also an upgrade of nvidia drivers. I am not sure if this issue started happening just after the upgrade or after Xorg upgrade.

When some pop-up window appears, like, for example, terminal name when I hoover the mouse over terminal tab in gnome terminal, or a tab in firefox, etc., and then disappears, the system freezes for a fraction of second. It is most visible when I run glxgears or play a movie (does not matter if vlc or other player). If I open applications pull down menu from the top bar there is also a freeze, but shorter. The freeze might be acceptable, but it is very annoying in programs that show some popups very often, like, for example, pycharm editor. Does anyone know how can I fix it? This behaviour affecting pyCharm seriously affects my work

The upgrade to Fedora 27 required also an upgrade of nvidia drivers to 384.111. Now I am running 390.12 and tested also 387.34. The problem is still there. Graphic output from inxi -F is:

Graphics: Card-1: Intel HD Graphics 530 Card-2: NVIDIA GP106M [GeForce GTX 1060 Mobile] Display Server: x11 (X.org 1.19.6 ) drivers: modesetting,nvidia Resolution: 1920x1200@59.95hz , 1920x1080@59.90hz OpenGL: renderer: GeForce GTX 1060/PCIe/SSE2 version: 4.5.0 NVIDIA 384.111

Also, I booted once to Wayland, which runs on Intel driver and single monitor only. The described issue was not happening then.

Do you have any idea what could be the cause of the problem?

Thank you!

Updating from F25 to F27, Gnome got upgraded 3.22->3.26 and this has issues with the nvidia driver due to changes in Mutter
https://bugzilla.gnome.org/show_bug.cgi?id=781835
This would be my guess what’s happening.

The problem is, that I don’t see any high CPU usage, even during these “hick-ups”…