Skip to content

[Webgpu] Avoid mappedAtCreation staging upload #29846

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Tianlei Wu (tianleiwu) merged 2 commits into from
Jul 26, 2026
Merged

[Webgpu] Avoid mappedAtCreation staging upload #29846

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e55f7da
webgpu: avoid mappedAtCreation staging upload
Copilot Jul 23, 2026
df70499
Potential fix for pull request finding
tianleiwu Jul 23, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 8 additions & 16 deletions js/web/lib/wasm/jsep/webgpu/gpu-data-manager.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -237,22 +237,14 @@ class GpuDataManagerImpl implements GpuDataManager {
throw new Error(`inconsistent data size. gpu data size=${gpuDataCache.originalSize}, data size=${srcLength}`);
}

// create gpu buffer
const gpuBufferForUploading = this.backend.device.createBuffer(
// eslint-disable-next-line no-bitwise
{ mappedAtCreation: true, size, usage: GPUBufferUsage.MAP_WRITE | GPUBufferUsage.COPY_SRC },
);

// copy (upload) data
const arrayBuffer = gpuBufferForUploading.getMappedRange();
new Uint8Array(arrayBuffer).set(new Uint8Array(srcArrayBuffer, srcOffset, srcLength));
gpuBufferForUploading.unmap();

// GPU copy
const commandEncoder = this.backend.device.createCommandEncoder();
commandEncoder.copyBufferToBuffer(gpuBufferForUploading, 0, gpuDataCache.gpuData.buffer, 0, size);
this.backend.device.queue.submit([commandEncoder.finish()]);
gpuBufferForUploading.destroy();
if (size === srcLength && srcOffset % 4 === 0) {
// Fast path: already aligned; avoid allocating/copying a padded buffer.
this.backend.device.queue.writeBuffer(gpuDataCache.gpuData.buffer, 0, srcArrayBuffer, srcOffset, srcLength);
} else {
const uploadData = new Uint8Array(size);
uploadData.set(data);
this.backend.device.queue.writeBuffer(gpuDataCache.gpuData.buffer, 0, uploadData, 0, size);
}

LOG_DEBUG('verbose', () => `[WebGPU] GpuDataManager.upload(id=${id})`);
}
Expand Down
Loading