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dawn / dawn / a07430f8768af9060936a03872c612b54911ace0
commita07430f8768af9060936a03872c612b54911ace0[log] [tgz]
authorAlbin Bernhardsson <albin.bernhardsson@arm.com>Mon Apr 22 15:25:44 2024 +0000
committerDawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com>Mon Apr 22 15:25:44 2024 +0000
tree7fcf5038e6bbec324e2ac968e23582aa544ee56c
parentb7c1a98e50cdfd4c7adc67fb5584c5f182b69c9a [diff]
Vulkan: Implement fast path for writeBuffer

Implement a fast path for writeBuffer in Vulkan where, instead of
writing data to a scratch buffer and then copying the data into the
destination buffer, the data is written directly into the destination
buffer. This reduces bandwidth by avoiding the extra copy and removes
the need to synchronize the transfer command, improving
synchronization.

To take the fast path:
1. The buffer's memory needs to be host visible. In practice this
   means this optimization is for integrated GPUs where memory is
   shared.
2. The buffer must not currently be in use. In practice this means
   the application needs to double buffer its uniform buffers.
3. There must not be any pending GPU writes to the buffer.

If the fast path can't be taken we will fall back to the current
implementation (writing to a scratch buffer and copying the data to
the destination buffer).

In a test Sponza scene, where the application does not manually
suballocate buffers, this reduces frame times by 11% on a Mali-G78
device.

Bug: dawn:774 dawn:851
Change-Id: Ib5f770297d5729df374d0f847a47ade6b0bf24ef
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/162780
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>
7 files changed
tree: 7fcf5038e6bbec324e2ac968e23582aa544ee56c
  1. .github/
  2. .vscode/
  3. build_overrides/
  4. docs/
  5. generator/
  6. include/
  7. infra/
  8. scripts/
  9. src/
  10. test/
  11. third_party/
  12. tools/
  13. webgpu-cts/
  14. build
  15. buildtools
  16. testing
  17. .bazelrc
  18. .clang-format
  19. .clang-tidy
  20. .gitattributes
  21. .gitignore
  22. .gitmodules
  23. .gn
  24. AUTHORS
  25. BUILD.bazel
  26. BUILD.gn
  27. CMakeLists.txt
  28. CMakeSettings.json
  29. CODE_OF_CONDUCT.md
  30. codereview.settings
  31. CONTRIBUTING.md
  32. CPPLINT.cfg
  33. DEPS
  34. DIR_METADATA
  35. go.mod
  36. go.sum
  37. go_presubmit_support.py
  38. LICENSE
  39. OWNERS
  40. PRESUBMIT.py
  41. README.chromium
  42. README.md
  43. WORKSPACE.bazel
README.md

Build Status Matrix Space

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs: D3D12, Metal, Vulkan and OpenGL. See per API support for more details.
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers
  • Tint is a compiler for the WebGPU Shader Language (WGSL) that can be used in standalone to convert shaders from and to WGSL.

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with the webgpu.h docs)

License

BSD 3-Clause License, please see LICENSE.

Disclaimer

This is not an officially supported Google product.