[Mesa-dev] [BUG] Large slowdown with RADV / Warcraft with latest Mesa from Git.

[Chris Rankin]

Hi,

I've just noticed a large drop in FPS (from 60 down to 15) when playing World of Warcraft with the latest Mesa from Git.
A quick git bisect has identified this commit:

4292fb2139282e6906d4ad2a8be2fd81ed7ca8af is the first bad commit
commit 4292fb2139282e6906d4ad2a8be2fd81ed7ca8af
Author: Michel Dänzer <mdaenzer at redhat.com>
Date:   Mon Dec 21 15:41:56 2020 +0100

    wsi/x11: Use PresentOptionAsync for MAILBOX present mode with Xwayland
    
    This allows Xwayland to forward buffers to the Wayland compositor ASAP
    for fullscreen / undecorated windows, which in turn allows true mailbox
    behaviour in the Wayland compositor.
    
    Without this, Xwayland has to emulate the mailbox behaviour itself,
    which it cannot do as well as the Wayland compositor by design.
    
    Reviewed-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
    Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8197>

 src/vulkan/wsi/wsi_common_x11.c | 7 +++++++
 1 file changed, 7 insertions(+)

I am playing WoW with this release of Wine:

wine-6.0-0.4rc4.fc33.x86_64

And this version of DXVK:

wine-dxvk-1.7.2-3.fc33.x86_64

Curiously, I am using Xorg rather than Wayland, and so don't understand why this commit should affect me.

Glxinfo reports the following:

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: AMD (0x1002)
    Device: AMD Radeon (TM) R7 300 Series (BONAIRE, DRM 3.40.0, 5.10.5, LLVM 12.0.0) (0x665f)
    Version: 21.0.0
    Accelerated: yes
    Video memory: 2048MB
    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: 1483 MB, largest block: 1483 MB
    VBO free aux. memory - total: 2691 MB, largest block: 2691 MB
    Texture free memory - total: 1483 MB, largest block: 1483 MB
    Texture free aux. memory - total: 2691 MB, largest block: 2691 MB
    Renderbuffer free memory - total: 1483 MB, largest block: 1483 MB
    Renderbuffer free aux. memory - total: 2691 MB, largest block: 2691 MB
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 2048 MB
    Total available memory: 5120 MB
    Currently available dedicated video memory: 1483 MB
OpenGL vendor string: AMD
OpenGL renderer string: AMD Radeon (TM) R7 300 Series (BONAIRE, DRM 3.40.0, 5.10.5, LLVM 12.0.0)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 21.0.0-devel (git-4292fb2139)

Cheers,
Chris