[NVIDIA] Mouse motion causes severe frame delays since linux_drm_syncobj implementation

[ShadowApex]

Is there an existing issue for this?

• I have searched the existing issues

Are you using any gamescope patches or a forked version of gamescope?

• The issue occurs on upstream gamescope without any modifications

Current Behavior

Using Nvidia GPUs with a 4k display, certain games like Cyberpunk 2077 and Black Myth: Wukong experience severe frame delays when there is mouse motion input. Keyboard or gamepad input does not cause issues. After bisecting, it appears this issue was introduced in commit dd77e4de10974bdbfe8252f6ec6f4c8723ac3305 with the introduction of the new linux_drm_syncobj implementation in v3.15.0.

From testing Cyberpunk 2077, it appears this issue only manifests when using a 4k display (tested with a 3840x2160 monitor) or when using a 1080p display and the in-game resolution is set to a value lower than 1080p. Enabling vsync in-game also appears to help with the frame stuttering, but is severe when it is disabled.

Steps To Reproduce

1. Launch gamescope embedded session (with a 4K display 3840x2160)
2. Launch Cyberpunk 2077
3. Go to game settings and ensure that resolution is set to 1920x1080 and vsync is disabled
4. Load or start a new game
5. Move mouse cursor around

Hardware information

- **Distro**: Fedora Linux 41.20241106.0 (Silverblue)
- **CPU**: 16-core Intel(R) Core(TM) Ultra 7 155H
- **GPU**: NVIDIA Corporation AD107M [GeForce RTX 4060 Max-Q / Mobile]
- **Driver Version**: NVIDIA 565.57.01

Software information

- **Desktop environment**: None (gamescope-session)
- **Session type**: wayland
- **Gamescope version**: gamescope version v3.15.0+ (starting at commit [dd77e4de10974bdbfe8252f6ec6f4c8723ac3305](https://github.com/ValveSoftware/gamescope/commit/dd77e4de10974bdbfe8252f6ec6f4c8723ac3305))
- **Gamescope launch command(s)**: `/usr/bin/gamescope --prefer-output *,eDP-1 --xwayland-count 2 --default-touch-mode 4 --hide-cursor-delay 3000 --fade-out-duration 200 --steam -R /run/user/1000/gamescope.rhDOTtu/startup.socket -T /run/user/1000/gamescope.rhDOTtu/stats.pipe`

Which gamescope backends have the issue you are reporting?

• Wayland (default for nested gamescope)
• DRM (default for embedded gamescope, i.e. gamescope-session)
• SDL
• OpenVR

Logging, screenshots, or anything else

gamescope version v3.15.0+ (dd77e4de10974bdbfe8252f6ec6f4c8723ac3305)

2024-11-11-14-23-09-090-clipped.mp4

gamescope version v3.14.29

2024-11-11-14-26-58-586.mp4

[alkazar]

I experience this issue at native 1080p with Senua's Sacrifice when using DirectX12, but not when using DirectX11.
The GPU used for testing was an RTX 4060.

[awsms]

Getting this on Cyberpunk as well (launch command: ENABLE_GAMESCOPE_WSI=0 gamescope -w 2560 -h 1440 --hdr-enabled --hdr-itm-enable --force-grab-cursor -- %command% --launcher-skip -skipStartScreen).
Playing with a controller is perfectly fine, but as soon as I try moving my mouse, it stutters to hell and my terminal is spammed with [gamescope] [Warn] xwm: got the same buffer committed twice, ignoring.
It's WAY MORE exaggerated than in OP's video, making the game impossible to play with a mouse for me

[matte-schwartz]

can you try adding VKD3D_DISABLE_EXTENSIONS=VK_KHR_present_wait before %command% as well? this seems to work around the mouse issue for me in Cyberpunk 2077 on a 4090 with HDR enabled on Plasma 6 Wayland and in gamescope-session.

[awsms]

can you try adding VKD3D_DISABLE_EXTENSIONS=VK_KHR_present_wait before %command% as well? this seems to work around the mouse issue for me in Cyberpunk 2077 on a 4090 with HDR enabled on Plasma 6 Wayland and in gamescope-session.

This reduces a lot the stutter duration, but still doesn't make it playable as the stutters are still there at every mouse move.
edit: btw it adds input latency for me.

[matte-schwartz]

NVIDIA/egl-wayland#154 hmm, i wonder if this is possibly related? i'm not too familiar with the egl-wayland repo though but this looks similar

[awsms]

NVIDIA/egl-wayland#154 hmm, i wonder if this is possibly related? i'm not too familiar with the egl-wayland repo though but this looks similar

Interesting, however he suffers of FPS drops and no stuttering, while my FPS are not affected at all (there is 0 difference in the frame time/framerate graphs displayed by mangohud when the stuttering occurs).

[drakon64]

can you try adding VKD3D_DISABLE_EXTENSIONS=VK_KHR_present_wait before %command% as well? this seems to work around the mouse issue for me in Cyberpunk 2077 on a 4090 with HDR enabled on Plasma 6 Wayland and in gamescope-session.

This resolved the issue for me in Marvel Rivals and Helldivers 2

[awsms]

I experience this issue at native 1080p with Senua's Sacrifice when using DirectX12, but not when using DirectX11. The GPU used for testing was an RTX 4060.

I can confirm this only happens on DX12 titles for me. Palworld with VKD3D stutters, while it doesn't at all with DXVK.

[matte-schwartz]

I had another look at the original issue reported here today (Cyberpunk 2077, 4K display + 1920x1080p in-game resolution. here's what I found (note - this is all with explicit sync enabled on gamescope 3.16.1):

ENABLE_GAMESCOPE_WSI=1 %command% - mouse does not lag, VK_KHR_present_wait will cause it to freeze (separate issue)
ENABLE_GAMESCOPE_WSI=1 VKD3D_DISABLE_EXTENSIONS=VK_KHR_present_wait %command% - mouse does not lag, game does not freeze

ENABLE_GAMESOPE_WSI=0 %command% - mouse lags severely when in-game
ENABLE_GAMESCOPE_WSI=0 VKD3D_DISABLE_EXTENSIONS=VK_KHR_present_wait %command% - mouse only lags a little bit

this behavior in Cyberpunk only happens on NVIDIA, so a NVIDIA label would be warranted here as well cc @kisak-valve

nvidia-bug-report.log.gz

[cch000]

Any updates?

[awsms]

Any updates?

None yet. But feel free to upload your bug report on the dedicated driver feedback thread: https://forums.developer.nvidia.com/t/565-release-feedback-discussion/310777

[cch000]

Is it possible to disable explicit sync support in gamescope? games run fine on drivers without an explicit sync implementation e.g. 550.x

[matte-schwartz]

You can flip

gamescope/src/Backends/DRMBackend.cpp

Line 72 in ef1e8db

gamescope::ConVar<bool> cv_drm_debug_disable_explicit_sync( "drm_debug_disable_explicit_sync", false, "Force disable explicit sync on the DRM backend." );

to true and re-compile

I think there's a way to do it with a Gamescope convar at runtime as well with a config file, but tbh I have not figured out how to get that working yet.

[cch000]

That fixed the issue for me on driver 565. For runtime it seems that it can be done through gamescopectl, but it would be nice to have it in a config file.

[MagicRB]

function info(text)
    gamescope.log(gamescope.log_priority.info, text)
end


info("Enabling explicit sync: " .. tostring(gamescope.convars.drm_debug_disable_explicit_sync.value) .. " -> " .. tostring(true))
gamescope.convars.drm_debug_disable_explicit_sync.value = true

this code in $XDG_CONFIG_DIR/gamescope/scripts/something.lua does the trick for me in Cyberpunk 2077. I'll go play my game now but later I'll try to make it autodetect proprietary NVidia drivers and auto apply only then.