https://bugs.kde.org/show_bug.cgi?id=450914
--- Comment #10 from Zamundaaa <xaver.h...@gmail.com> --- There is some weird interaction of Xwayland with windowed contents that can cause something similar: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1309 The timer in Xwayland is about 58-59fps, not 60 though, so it's most likely not the same issue. It also happens in other compositors, so there's that... > Is there possibly a difference between NVIDIA and Mesa that could cause Kwin > to delay releasing these buffers? How many buffers does the NVidia driver allocate for a swapchain? While I really doubt that a lack of free buffers would manage to get exact smooth 60fps, Mesa needed to bump the number of buffers in Wayland and Xwayland up to 4 in order to remove some bottlenecks with direct scanout. @Samuel you can quickly check if direct scanout makes a difference by putting KWIN_DRM_NO_DIRECT_SCANOUT=1 into /etc/environment and rebooting One other thing that interacts with buffer releases is that KWin does dynamic frame scheduling, which neither Sway nor AFAIK a currently released version of Mutter do; Mutter always renders at vblank and IIRC Sway does so too by default. KWin with default settings starts compositing somewhere in the middle of the frame (depends on GPU load and user settings) > There is one known bug in our DRM driver where we don't report the correct > timestamp for page flips (it will just be 0), not sure if that could be > relevant KWin fakes the timestamp to be at the time of receiving the callback if it's not correct, it probably doesn't make a significant difference. -- You are receiving this mail because: You are watching all bug changes.
