| Summary: | Plasma 6: Half the FPS with atomic mode setting | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Peter Eszlari <peter.eszlari> |
| Component: | wayland-generic | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | hedim74889, jlp, nate, syed.talha.khalid |
| Priority: | NOR | Keywords: | qt6 |
| Version: | git master | ||
| Target Milestone: | --- | ||
| Platform: | Neon | ||
| OS: | Linux | ||
| Latest Commit: | https://invent.kde.org/plasma/kwin/-/commit/869e86ff0014e020c4076a8f22e78f69cab1063a | Version Fixed In: | |
| Sentry Crash Report: | |||
| Attachments: | kwin info | ||
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/4632 Git commit 869e86ff0014e020c4076a8f22e78f69cab1063a by Xaver Hugl. Committed on 13/11/2023 at 15:33. Pushed by zamundaaa into branch 'master'. backends/drm: disable buffer readability checks on Intel They cause stutters and reduced frame rates on some Intel laptops because the buffers don't become readable in time, so disable the checks until that's fixed on the driver side. For debugging purposes, the environment variable KWIN_DRM_DISABLE_BUFFER_READABILITY_CHECKS can be used to override the default behavior. M +8 -0 src/backends/drm/drm_buffer.cpp M +6 -0 src/backends/drm/drm_gpu.cpp M +2 -0 src/backends/drm/drm_gpu.h https://invent.kde.org/plasma/kwin/-/commit/869e86ff0014e020c4076a8f22e78f69cab1063a *** Bug 477483 has been marked as a duplicate of this bug. *** I don't have this bug in plasma 5.27.10 on Fedora KDE. But the bug is persistent on Plasma 6. I have tested on Neon & Fedora Rawhide. My cpu is i5-9500 (uhd 630). |
Created attachment 163063 [details] kwin info SUMMARY When running Plasma 6 Wayland session on my old Intel Haswell system, I get half the FPS (30 instead of 60). STEPS TO REPRODUCE 1. login in to a Plasma 6 Wayland session 2. enable "Show FPS" desktop effect OBSERVED RESULT The "Show FPS" desktop effect show a value of ~30fps, with jumps up to 50fps, when interacting with the desktop. EXPECTED RESULT Constant 60fps. SOFTWARE/OS VERSIONS Operating System: KDE neon Unstable Edition KDE Plasma Version: 5.27.80 KDE Frameworks Version: 5.245.0 Qt Version: 6.6.0 Kernel Version: 6.2.0-36-generic (64-bit) Graphics Platform: Wayland Processors: 4 × Intel® Core™ i5-4690 CPU @ 3.50GHz Memory: 22.4 GiB of RAM Graphics Processor: Mesa Intel® HD Graphics 4600 ADDITIONAL INFORMATION This works in Plasma6/X11, Plasma5/Wayland and Plasma5/X11 on the same computer. Under Plasma6/Wayland I get a constant 60fps when disabling atomic mode setting using KWIN_DRM_NO_AMS=1.