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Are there still workarounds for specific games/programs inside the driver?

by de_watcher 6y ago

TheFlash 6y ago
Yes. In fact, that's essentially what the drivers are.
- psykotic 6y ago
  Leaving aside arguments about "what the drivers are", the kernel driver being discussed here generally doesn't have or need that kind of thing. The user-space drivers which talk to the kernel drivers are under the Mesa umbrella as part of Gallium for OpenGL and Direct3D support (e.g. https://github.com/mesa3d/mesa/tree/master/src/gallium/drivers/radeonsi https://github.com/mesa3d/mesa/tree/master/src/gallium/drive...) or as a standalone driver for Vulkan support (https://github.com/mesa3d/mesa/tree/master/src/amd/vulkan https://github.com/mesa3d/mesa/tree/master/src/amd/vulkan). That said, I haven't seen many app-specific hacks in the open source drivers, even in the user-space code. If anyone wants to learn more about lower-level aspects of GPUs, the Vulkan driver code I linked is one of the best places to start. It directly implements the Vulkan API on one end and talks to the kernel drivers on the other end, so it's relatively easy to follow if you're a systems programmer with an API-level understanding of graphics. Just pick a Vulkan function of your choice and start tracing through the code, e.g. vkCmdDraw: https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/radv_cmd_buffer.c#L5365 https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/ra.... The Vulkan driver calls into some of the low-level radeonsi code I linked from the Gallium tree but it isn't a Gallium-based driver, so you don't have to deal with those extra layers of abstraction.
  - account42 6y ago
    > That said, I haven't seen many app-specific hacks in the open source drivers, even in the user-space code. They are enabled via driconf [0]. Not nearly as many as what I imagine you'd find in the proprietary Windows drivers though. [0] https://github.com/mesa3d/mesa/blob/master/src/util/00-mesa-defaults.conf https://github.com/mesa3d/mesa/blob/master/src/util/00-mesa-...
    - Audiophilip 6y ago
      Also: https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/radv_device.c#L561 https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/ra...
Cloudef 6y ago
You can see all the workaround used in mesa here: https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/src/util/00-mesa-defaults.conf https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/src/u... Propriatery drivers (especially nvidia), most likely has lots of similar game specific workarounds and optimizations (even going as far as overriding shaders in games with better ones they wrote). [1] 1: https://www.gamedev.net/forums/topic/666419-what-are-your-opinions-on-dx12vulkanmantle/5215019/ https://www.gamedev.net/forums/topic/666419-what-are-your-op...
- deleted 6y ago
  [deleted]

Are there still workarounds for specific games/programs inside the driver?

TheFlash 6y ago

Yes. In fact, that's essentially what the drivers are.

psykotic 6y ago
Leaving aside arguments about "what the drivers are", the kernel driver being discussed here generally doesn't have or need that kind of thing. The user-space drivers which talk to the kernel drivers are under the Mesa umbrella as part of Gallium for OpenGL and Direct3D support (e.g. https://github.com/mesa3d/mesa/tree/master/src/gallium/drivers/radeonsi https://github.com/mesa3d/mesa/tree/master/src/gallium/drive...) or as a standalone driver for Vulkan support (https://github.com/mesa3d/mesa/tree/master/src/amd/vulkan https://github.com/mesa3d/mesa/tree/master/src/amd/vulkan). That said, I haven't seen many app-specific hacks in the open source drivers, even in the user-space code. If anyone wants to learn more about lower-level aspects of GPUs, the Vulkan driver code I linked is one of the best places to start. It directly implements the Vulkan API on one end and talks to the kernel drivers on the other end, so it's relatively easy to follow if you're a systems programmer with an API-level understanding of graphics. Just pick a Vulkan function of your choice and start tracing through the code, e.g. vkCmdDraw: https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/radv_cmd_buffer.c#L5365 https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/ra.... The Vulkan driver calls into some of the low-level radeonsi code I linked from the Gallium tree but it isn't a Gallium-based driver, so you don't have to deal with those extra layers of abstraction.
- account42 6y ago
  > That said, I haven't seen many app-specific hacks in the open source drivers, even in the user-space code. They are enabled via driconf [0]. Not nearly as many as what I imagine you'd find in the proprietary Windows drivers though. [0] https://github.com/mesa3d/mesa/blob/master/src/util/00-mesa-defaults.conf https://github.com/mesa3d/mesa/blob/master/src/util/00-mesa-...
  - Audiophilip 6y ago
    Also: https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/radv_device.c#L561 https://github.com/mesa3d/mesa/blob/master/src/amd/vulkan/ra...

Cloudef 6y ago

You can see all the workaround used in mesa here: https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/src/util/00-mesa-defaults.conf https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/src/u... Propriatery drivers (especially nvidia), most likely has lots of similar game specific workarounds and optimizations (even going as far as overriding shaders in games with better ones they wrote). [1] 1: https://www.gamedev.net/forums/topic/666419-what-are-your-opinions-on-dx12vulkanmantle/5215019/ https://www.gamedev.net/forums/topic/666419-what-are-your-op...

deleted 6y ago
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