SUMMARY *** NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports *** STEPS TO REPRODUCE 1. Install Fedora 37 KDE spin 2. plug in an egpu RX 5700 3. plug in monitor into egpu 4. reboot OBSERVED RESULT both laptop and external display work. laptop display is buttery smooth. external display is choppy. EXPECTED RESULT Both laptop and the external display work. laptop display is buttery smooth. external display is buttery smooth SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Fedora 37 KDE spin Plasma: 5.26.5 (available in About System) KDE Plasma Version: 5.26.5 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 ADDITIONAL INFORMATION I am running wayland with a display plugged into an egpu Radeon RX5700. I created a post with my laptop manufacturer with some additional details: https://community.frame.work/t/linux-poor-performance-of-egpu-driven-external-monitor-in-fedora-37-kde-spin/27290 After running the following script to designate my egpu as primary per this project: https://github.com/ewagner12/all-ways-egpu/wiki I now observe the external display is smooth and the integrated display is now choppy. My suggestion would be to either run the display on the gpu for which it is designated and give options to switch this or provide an option within KDE to select which GPU to use and note that the other will perform poorly Perhaps the choppiness is also an issue with wayland or kwin that could in itself be resolved? Being able to choose which gpu to use is still needed for tasks like running games though
probably a duplicate of https://bugs.kde.org/show_bug.cgi?id=452219
Bug 452219 is more about NVidia GPUs specifically, but yeah it's most likely the same underlying issue. Please attach the output of drm_info (https://gitlab.freedesktop.org/emersion/drm_info), whether or not KWin falls back to CPU copy should be visible in there.
Created attachment 156551 [details] drm_info output from freshly installed fedora 37 with all updates This drm_info was collected from a freshly installed fedora 37 kde spin with the updates as of today, which includes kde 5.27
(In reply to Zamundaaa from comment #2) > Bug 452219 is more about NVidia GPUs specifically, but yeah it's most likely > the same underlying issue. > Please attach the output of drm_info > (https://gitlab.freedesktop.org/emersion/drm_info), whether or not KWin > falls back to CPU copy should be visible in there. The file is attached. I reinstalled fedora 37 onto a new partition so that I could ensure the egpu script i ran was not a factor. I'll keep it this way for troubleshooting purposes for a while
Git commit b14f7959eb5f4d2b690ac26fdfee76abc837240c by Xaver Hugl. Committed on 12/04/2023 at 13:28. Pushed by zamundaaa into branch 'master'. backends/drm: add another multi gpu fallback With the dmabuf multi-gpu path, a buffer is imported to the secondary GPU and presented directly, but importing a buffer that's usable for scanout is not possible that way on most hardware. To prevent CPU copy from being needed in those cases, this commit introduces a fallback where the buffer is imported for rendering only, and then copied to a local buffer that's presented on the screen. Related: bug 452219 M +73 -43 src/backends/drm/drm_egl_backend.cpp M +5 -3 src/backends/drm/drm_egl_backend.h M +92 -15 src/backends/drm/drm_egl_layer_surface.cpp M +7 -3 src/backends/drm/drm_egl_layer_surface.h M +5 -0 src/composite.cpp M +1 -2 src/libkwineffects/kwinglutils.h M +18 -0 src/platformsupport/scenes/opengl/eglcontext.cpp M +7 -3 src/platformsupport/scenes/opengl/eglcontext.h https://invent.kde.org/plasma/kwin/commit/b14f7959eb5f4d2b690ac26fdfee76abc837240c
^^ That should fix it!
Significant stutter still present on secondary monitor, and shortly after moving cursor to primary eDP display. EXPECTED RESULT: Plasma selects the proper GPU/Prime topology upon login and provides a smooth consistent 60fps through the external and internal display Operating System: Arch Linux KDE Plasma Version: 5.27.10 KDE Frameworks Version: 5.112.0 Qt Version: 5.15.11 Kernel Version: 6.6.4-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz Memory: 7.5 GiB of RAM Graphics Processor: Mesa Intel® UHD Graphics 620 (Secondary GP: AMD 5500XT via Sonnet Breakaway Box over Thunderbolt 3) Manufacturer: Dell Inc. Product Name: XPS 13 9370
(In reply to Matt from comment #7) > Significant stutter still present on secondary monitor, and shortly after > moving cursor to primary eDP display. That's expected, you're on 5.27, which doesn't have the fix.
Created attachment 164024 [details] Arch Linux drm_info output
(In reply to Zamundaaa from comment #8) > (In reply to Matt from comment #7) > > Significant stutter still present on secondary monitor, and shortly after > > moving cursor to primary eDP display. > That's expected, you're on 5.27, which doesn't have the fix. Oh, my mistake. I misread the version info; the amount of time we've spent in 5.27 is pretty crazy!