Shangdi Yu 77bf23d85c Add an option to put store large mmap weights on disk (#164526) ...

As title

In windows, we cannot modify the .dll to append weights at the end, the windows .dll loader will complain it's not a valid .dll file. So we store the weight blob as a separete file.

1. We add the following API which allows passing in a pointer to the weight blob and get the size of the weight blob.

```cpp
AOTI_API AOTIRuntimeError AOTInductorModelContainerGetConstantsBlobSize(
    AOTInductorModelContainerHandle container_handle,
    uint64_t* ret_size);

// Load weights from a single blob in weight_blob_ptr
AOTI_API AOTIRuntimeError AOTInductorModelUpdateConstantsFromBlob(
    AOTInductorModelContainerHandle container_handle,
    const uint8_t* weight_blob_ptr);
```

2. We also add a method in ModelContainerRunner to load the weight:

If the runner see that there is a `.blob` file in the package, if will mmap the .blob file and use the content to load the constants.

3. We also add the `USE_MMAP_EXTERNAL` macro. When this macro is defined, the model expects to load the weights from external mmap'd weights.

Test Plan:

```
buck run @mode/dev-nosan caffe2/test/inductor:test_aot_inductor -- -r test_large_mmaped_weights_on_disk
```

Also tested for windows-cross compilation with 6542566585/demo/main_voxtral.cpp

```
Loaded model.dll
audio_encoder loaded
C:\Users\shangdiy\source\repos\torchnative\demo\token_embedding\data\aotinductor\model\model.wrapper.so
Loaded model.dll
token_embedding loaded
C:\Users\shangdiy\source\repos\torchnative\demo\text_decoder\data\aotinductor\model\model.wrapper.so
Loaded model.dll
Loading weights from C:\Users\shangdiy\source\repos\torchnative\demo\text_decoder\data\aotinductor\model\model.wrapper_weights.blob
text_decoder loaded
Load latency (ms):
  audio_encoder: 1011.234
    archive extraction: 0.000
    .so loading: 1011.197
  token_embedding: 525.773
    archive extraction: 0.000
    .so loading: 525.704
  text_decoder: 3324.130
    archive extraction: 0.000
    .so loading: 3323.979
Run latency (ms):
  audio_encoder: 285.958
    audio_encoder output: dtype=bfloat16, shape=[1, 1125, 3072], numel=3456000
  token_embedding: 6.676
    token_embedding output: dtype=bfloat16, shape=[1, 1138, 3072], numel=3495936
  text_decoder: 576.519
    text_decoder output: dtype=bfloat16, shape=[1, 1138, 131072], numel=149159936
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/164526
Approved by: https://github.com/desertfire

2025-10-10 07:53:57 +00:00

..

interface.cpp

Add an option to put store large mmap weights on disk (#164526)

2025-10-10 07:53:57 +00:00