使用ATI_meminfo和/或NVX_gpu_memory_info在程序启动时获取GL空闲内存（“A”），然后在需要当前分配时再次获取（“B”）。A - B是实际分配的内存。
Radeon RX 6700 XT上的梅萨22.3.3同时支持ATI_meminfo和NVX_gpu_memory_info：

$ glxinfo
...
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: AMD (0x1002)
    Device: AMD Radeon RX 6700 XT (navi22, LLVM 15.0.6, DRM 3.49, 6.1.0-5-amd64) (0x73df)
    Version: 22.3.3
    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: 11410 MB, largest block: 11410 MB
    VBO free aux. memory - total: 15549 MB, largest block: 15549 MB
    Texture free memory - total: 11410 MB, largest block: 11410 MB
    Texture free aux. memory - total: 15549 MB, largest block: 15549 MB
    Renderbuffer free memory - total: 11410 MB, largest block: 11410 MB
    Renderbuffer free aux. memory - total: 15549 MB, largest block: 15549 MB
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 12288 MB
    Total available memory: 28301 MB
    Currently available dedicated video memory: 11410 MB
OpenGL vendor string: AMD
OpenGL renderer string: AMD Radeon RX 6700 XT (navi22, LLVM 15.0.6, DRM 3.49, 6.1.0-5-amd64)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 22.3.3
OpenGL core profile shading language version string: 4.60
...

然而，当经由LIBGL_ALWAYS_SOFTWARE=true强制软件渲染时，这些扩展被 * 不 * 报告;它所能做的最好的是GLX_MESA_query_renderer的GLX_RENDERER_VIDEO_MEMORY_MESA（Video memory:线）：

$ LIBGL_ALWAYS_SOFTWARE=1 glxinfo
...
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Mesa/X.org (0xffffffff)
    Device: llvmpipe (LLVM 15.0.6, 256 bits) (0xffffffff)
    Version: 22.3.3
    Accelerated: no
    Video memory: 32026MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 4.5
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Mesa/X.org
OpenGL renderer string: llvmpipe (LLVM 15.0.6, 256 bits)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 22.3.3
OpenGL core profile shading language version string: 4.50
...