vsync stuttering with egl backend

[pasja]

Platform

Debian Bookworm (12.5)

GPU, drivers, and screen setup

Radeon RX 6750 XT 12GB GDDR6, one 1140p monitor

glxinfo -B:
name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: AMD (0x1002)
    Device: AMD Radeon RX 6750 XT (navi22, LLVM 15.0.6, DRM 3.54, 6.5.0-5-amd64) (0x73df)
    Version: 22.3.6
    Accelerated: yes
    Video memory: 12288MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
Memory info (GL_ATI_meminfo):
    VBO free memory - total: 11429 MB, largest block: 11429 MB
    VBO free aux. memory - total: 15927 MB, largest block: 15927 MB
    Texture free memory - total: 11429 MB, largest block: 11429 MB
    Texture free aux. memory - total: 15927 MB, largest block: 15927 MB
    Renderbuffer free memory - total: 11429 MB, largest block: 11429 MB
    Renderbuffer free aux. memory - total: 15927 MB, largest block: 15927 MB
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 12288 MB
    Total available memory: 28284 MB
    Currently available dedicated video memory: 11429 MB
OpenGL vendor string: AMD
OpenGL renderer string: AMD Radeon RX 6750 XT (navi22, LLVM 15.0.6, DRM 3.54, 6.5.0-5-amd64)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 22.3.6
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
 
OpenGL version string: 4.6 (Compatibility Profile) Mesa 22.3.6
OpenGL shading language version string: 4.60
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile
 
OpenGL ES profile version string: OpenGL ES 3.2 Mesa 22.3.6
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

Environment

xmonad with this config: https://github.com/pasja/dotfiles/blob/master/.xmonad/xmonad.hs%23%23hostname.asgard

picom version

vgit-89c2c

Diagnostics

picom --diagnostics [ 03/03/2024 14:10:25.074 get_cfg WARN ] The egl backend is still experimental, use with care.

Version: vgit-89c2c

Extensions:

• Shape: Yes
• RandR: Yes
• Present: Present

Misc:

• Use Overlay: No
  (Another compositor is already running)
• Config file used: /home/pasja/.config/picom/picom.conf

Drivers (inaccurate):

AMDGPU, Radeon

Backend: glx

• Driver vendors:
• GLX: Mesa Project and SGI
• GL: AMD
• GL renderer: AMD Radeon RX 6750 XT (navi22, LLVM 15.0.6, DRM 3.54, 6.5.0-5-amd64)
• Accelerated: 1

Backend: egl

• Driver vendors:
• EGL: Mesa Project
• EGL driver: radeonsi
• GL: AMD
• GL renderer: AMD Radeon RX 6750 XT (navi22, LLVM 15.0.6, DRM 3.54, 6.5.0-5-amd64)
  pasja@asgard ~ %

Configuration:

Configuration file

#################################
#       General Settings        #
#################################

# Daemonize process. Fork to background after initialization. Causes issues with certain (badly-written) drivers.
# daemon = false

# Specify the backend to use: `xrender`, `glx`, or `xr_glx_hybrid`.
# `xrender` is the default one.
#
backend = "egl";
# backend = "xrender";

# Enable/disable VSync.
# vsync = false
vsync = true

Steps of reproduction

1. Watch a fullscreen youtube video for ~2 minutes with my config
2. Experience a small freeze, audio works well, but screen is frozen, keyboard inputs are not working
3. after 1-2s everything goes back to normal

Expected behavior

picom should not freeze with the egl backend

Current Behavior

freezes are happening

Remarks

• the symptoms are very similar to vsync causes intermittent freezes with picom v11 #1166 but I use amdgpu and egl backend
• with xrender the issue happens less frequently, but the vsync introduced delay is almost unbearable
• please let me know if you need any further information from me