deepin-ocr/3rdparty/ncnn/docs/how-to-use-and-FAQ/vulkan-notes.md
wangzhengyang 718c41634f feat: 切换后端至PaddleOCR-NCNN,切换工程为CMake
1.项目后端整体迁移至PaddleOCR-NCNN算法,已通过基本的兼容性测试
2.工程改为使用CMake组织,后续为了更好地兼容第三方库,不再提供QMake工程
3.重整权利声明文件,重整代码工程,确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN,切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c
2022-05-10 10:22:11 +08:00

174 lines
3.3 KiB
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## supported platform
* Y = known work
* ? = shall work, not confirmed
* / = not applied
| |windows|linux|android|mac|ios|
|---|---|---|---|---|---|
|intel|Y|Y|?|?|/|
|amd|Y|Y|/|?|/|
|nvidia|Y|Y|?|/|/|
|qcom|/|/|Y|/|/|
|apple|/|/|/|?|Y|
|arm|/|?|?|/|/|
## enable vulkan compute support
```
$ sudo dnf install vulkan-devel
$ cmake -DNCNN_VULKAN=ON ..
```
## enable vulkan compute inference
```cpp
ncnn::Net net;
net.opt.use_vulkan_compute = 1;
```
## proper allocator usage
```cpp
ncnn::VkAllocator* blob_vkallocator = vkdev.acquire_blob_allocator();
ncnn::VkAllocator* staging_vkallocator = vkdev.acquire_blob_allocator();
net.opt.blob_vkallocator = blob_vkallocator;
net.opt.workspace_vkallocator = blob_vkallocator;
net.opt.staging_vkallocator = staging_vkallocator;
// ....
// after inference
vkdev.reclaim_blob_allocator(blob_vkallocator);
vkdev.reclaim_staging_allocator(staging_vkallocator);
```
## select gpu device
```cpp
// get gpu count
int gpu_count = ncnn::get_gpu_count();
// set specified vulkan device before loading param and model
net.set_vulkan_device(0); // use device-0
net.set_vulkan_device(1); // use device-1
```
## zero-copy on unified memory device
```cpp
ncnn::VkMat blob_gpu;
ncnn::Mat mapped = blob_gpu.mapped();
// use mapped.data directly
```
## hybrid cpu/gpu inference
```cpp
ncnn::Extractor ex_cpu = net.create_extractor();
ncnn::Extractor ex_gpu = net.create_extractor();
ex_cpu.set_vulkan_compute(false);
ex_gpu.set_vulkan_compute(true);
#pragma omp parallel sections
{
#pragma omp section
{
ex_cpu.input();
ex_cpu.extract();
}
#pragma omp section
{
ex_gpu.input();
ex_gpu.extract();
}
}
```
## zero-copy gpu inference chaining
```cpp
ncnn::Extractor ex1 = net1.create_extractor();
ncnn::Extractor ex2 = net2.create_extractor();
ncnn::VkCompute cmd(&vkdev);
ncnn::VkMat conv1;
ncnn::VkMat conv2;
ncnn::VkMat conv3;
ex1.input("conv1", conv1);
ex1.extract("conv2", conv2, cmd);
ex2.input("conv2", conv2);
ex2.extract("conv3", conv3, cmd);
cmd.submit();
cmd.wait();
```
## batch inference
```cpp
int max_batch_size = vkdev->info.compute_queue_count;
ncnn::Mat inputs[1000];
ncnn::Mat outputs[1000];
#pragma omp parallel for num_threads(max_batch_size)
for (int i=0; i<1000; i++)
{
ncnn::Extractor ex = net1.create_extractor();
ex.input("data", inputs[i]);
ex.extract("prob", outputs[i]);
}
```
## control storage and arithmetic precision
disable all lower-precision optimizations, get full fp32 precision
```cpp
ncnn::Net net;
net.opt.use_fp16_packed = false;
net.opt.use_fp16_storage = false;
net.opt.use_fp16_arithmetic = false;
net.opt.use_int8_storage = false;
net.opt.use_int8_arithmetic = false;
```
## debugging tips
```cpp
#define ENABLE_VALIDATION_LAYER 1 // modify to 1 in gpu.cpp
```
## add vulkan compute support to layer
1. add vulkan shader in src/layer/shader/
2. upload model weight data in Layer::upload_model()
3. setup pipeline in Layer::create_pipeline()
4. destroy pipeline in Layer::destroy_pipeline()
5. record command in Layer::forward()
## add optimized shader path
1. add vulkan shader in src/layer/shader/ named XXX_abc.comp
2. create pipeline with "XXX_abc"
3. record command using XXX_abc pipeline
## low-level op api
1. create layer
2. load param and load model
3. upload model
4. create pipeline
5. new command
6. record
7. submit and wait