[major] add setDevice & load weights from pytorch

nunchaku/csrc/flux.h

@@ -10,10 +10,13 @@
 class QuantizedFluxModel : public ModuleWrapper<FluxModel> { // : public torch::CustomClassHolder {
 public:
     void init(bool use_fp4, bool offload, bool bf16, int8_t deviceId) {
-        spdlog::info("Initializing QuantizedFluxModel");
+        spdlog::info("Initializing QuantizedFluxModel on device {}", deviceId);
         if (offload) {
             spdlog::info("Layer offloading enabled");
         }
+        ModuleWrapper::init(deviceId);
+
+        CUDADeviceContext ctx(this->deviceId);
         net = std::make_unique<FluxModel>(use_fp4, offload, bf16 ? Tensor::BF16 : Tensor::FP16, Device::cuda((int)deviceId));
     }
 
@@ -27,6 +30,7 @@ public:
         bool skip_first_layer = false)
     {
         checkModel();
+        CUDADeviceContext ctx(deviceId);
 
         spdlog::debug("QuantizedFluxModel forward");
 
@@ -61,6 +65,8 @@ public:
         torch::Tensor rotary_emb_img,
         torch::Tensor rotary_emb_context)
     {
+        CUDADeviceContext ctx(deviceId);
+
         spdlog::debug("QuantizedFluxModel forward_layer {}", idx);
 
         hidden_states = hidden_states.contiguous();
@@ -91,6 +97,8 @@ public:
         torch::Tensor temb,
         torch::Tensor rotary_emb_single)
     {
+        CUDADeviceContext ctx(deviceId);
+
         spdlog::debug("QuantizedFluxModel forward_single_layer {}", idx);
 
         hidden_states = hidden_states.contiguous();
@@ -117,6 +125,8 @@ public:
             throw std::invalid_argument("skipRanks must be multiples of 16");
         }
 
+        CUDADeviceContext ctx(deviceId);
+
         spdlog::info("Set lora scale to {} (skip {} ranks)", scale, skipRanks);
 
         net->traverse([&](Module *module) {

nunchaku/csrc/module.h

@@ -9,7 +9,12 @@
 template<typename M>
 class ModuleWrapper {
 public:
+    void init(int deviceId) {
+        this->deviceId = deviceId;
+    }
     void reset() {
+        CUDADeviceContext ctx(this->deviceId);
+
         debugContext.reset();
         net.reset();
         Tensor::synchronizeDevice();
@@ -20,6 +25,7 @@ public:
 
     void load(std::string path, bool partial = false) {
         checkModel();
+        CUDADeviceContext ctx(this->deviceId);
 
         spdlog::info("{} weights from {}", partial ? "Loading partial" : "Loading", path);
         
@@ -30,6 +36,19 @@ public:
         spdlog::info("Done.");
     }
 
+    void loadDict(std::map<std::string, torch::Tensor> dict, bool partial = false) {
+        checkModel();
+        CUDADeviceContext ctx(this->deviceId);
+
+        spdlog::info("{} weights from pytorch", partial ? "Loading partial" : "Loading");
+        
+        std::shared_ptr<TensorsProviderTorch> provider = std::make_shared<TensorsProviderTorch>(std::move(dict));
+        net->loadParams(*provider, partial);
+        Tensor::synchronizeDevice();
+
+        spdlog::info("Done.");
+    }
+
     void startDebug() {
         debugContext = std::make_unique<DebugContext>();
     }
@@ -38,6 +57,8 @@ public:
     }
 
     auto getDebugResults() {
+        CUDADeviceContext ctx(this->deviceId);
+
         std::map<std::string, torch::Tensor> result;
 
         if (debugContext) {
@@ -59,4 +80,6 @@ protected:
 protected:
     std::unique_ptr<M> net;
     std::unique_ptr<DebugContext> debugContext;
+
+    int deviceId = -1;
 };
\ No newline at end of file

nunchaku/csrc/pybind.cpp

@@ -22,6 +22,10 @@ PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
             py::arg("path"),
             py::arg("partial") = false
         )
+        .def("loadDict", &QuantizedFluxModel::loadDict, 
+            py::arg("dict"),
+            py::arg("partial") = false
+        )
         .def("forward", &QuantizedFluxModel::forward)
         .def("forward_layer", &QuantizedFluxModel::forward_layer)
         .def("forward_single_layer", &QuantizedFluxModel::forward_single_layer)
@@ -45,6 +49,10 @@ PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
             py::arg("path"),
             py::arg("partial") = false
         )
+        .def("loadDict", &QuantizedSanaModel::loadDict, 
+            py::arg("dict"),
+            py::arg("partial") = false
+        )
         .def("forward", &QuantizedSanaModel::forward)
         .def("forward_layer", &QuantizedSanaModel::forward_layer)
         .def("startDebug", &QuantizedSanaModel::startDebug)

nunchaku/csrc/sana.h

@@ -9,7 +9,7 @@
 class QuantizedSanaModel : public ModuleWrapper<SanaModel> {
 public:
     void init(pybind11::dict config, std::vector<int> pag_layers, bool use_fp4, bool bf16, int8_t deviceId) {
-        spdlog::info("Initializing QuantizedSanaModel");
+        spdlog::info("Initializing QuantizedSanaModel on device {}", deviceId);
         SanaConfig cfg{
             .num_layers = config["num_layers"].cast<int>(),
             .num_attention_heads = config["num_attention_heads"].cast<int>(),
@@ -19,6 +19,9 @@ public:
             .pag_layers = pag_layers,
             .use_fp4 = use_fp4,
         };
+
+        ModuleWrapper::init(deviceId);
+        CUDADeviceContext ctx(this->deviceId);
         net = std::make_unique<SanaModel>(cfg, bf16 ? Tensor::BF16 : Tensor::FP16, Device::cuda((int)deviceId));
     }
 
@@ -34,6 +37,7 @@ public:
         bool cfg) 
     {
         checkModel();
+        CUDADeviceContext ctx(deviceId);
 
         spdlog::debug("QuantizedSanaModel forward");
 
@@ -72,6 +76,7 @@ public:
         bool cfg) 
     {
         checkModel();
+        CUDADeviceContext ctx(deviceId);
 
         spdlog::debug("QuantizedSanaModel forward_layer {}", idx);
 

src/Tensor.h

@@ -81,7 +81,8 @@ public:
     BufferCUDA(size_t size) {
         this->size = size;
         this->device.type = Device::CUDA;
-        checkCUDA(cudaGetDevice(&this->device.idx));
+        // checkCUDA(cudaGetDevice(&this->device.idx));
+        this->device.idx = CUDADeviceContext::getDevice();
         if (size == 0) {
             this->ptr = nullptr;
         }
@@ -418,6 +419,7 @@ public:
             result.buffer = std::make_shared<BufferMalloc>(shape.size() * scalarSize.at(scalarType));
         } else if (device.type == Device::CUDA) {
             // TODO: cross device allocate
+            CUDADeviceContext ctx(device.idx);
             result.buffer = std::make_shared<BufferCUDA>(shape.size() * scalarSize.at(scalarType));
         } else {
             assert(false);
@@ -429,6 +431,7 @@ public:
             if (device.type == Device::CPU) {
                 memset(result.buffer->getPtr(), 0xCC, result.buffer->getSize());
             } else if (device.type == Device::CUDA) {
+                CUDADeviceContext ctx(device.idx);
                 checkCUDA(cudaMemsetAsync(result.buffer->getPtr(), 0xCC, result.buffer->getSize(), getCurrentCUDAStream()));
             }
         }

src/common.h

@@ -107,16 +107,97 @@ struct CUDAEventWrapper {
     }
 };
 
+
+/**
+ * 1. hold one when entered from external code (set `device` to -1 to avoid device change)
+ * 2. hold one when switching device
+ * 3. hold one with `disableCache` when calling external code that may change the device
+ */
+class CUDADeviceContext {
+public:
+    CUDADeviceContext(int device = -1, bool disableCache = false) : disableCache(disableCache) {
+        if (cacheDisabled()) {
+            // no previous context => we might entered from external code, reset cache
+            // previous context is reset on => external code may be executed, reset
+            currentDeviceCache = -1;
+        }
+        
+        ctxs.push(this);
+        lastDevice = getDevice();
+        if (device >= 0) {
+            setDevice(device);
+        }
+
+        if (disableCache) {
+            // we are about to call external code, reset cache
+            currentDeviceCache = -1;
+        }
+    }
+    CUDADeviceContext(const CUDADeviceContext &) = delete;
+    CUDADeviceContext(CUDADeviceContext &&) = delete;
+
+    ~CUDADeviceContext() {
+        if (disableCache) {
+            // retured from external code, cache is not reliable, reset
+            currentDeviceCache = -1;
+        }
+
+        setDevice(lastDevice);
+        assert(ctxs.top() == this);
+        ctxs.pop();
+
+        if (cacheDisabled()) {
+            // ctxs.empty() => we are about to return to external code, reset cache
+            // otherwise => we are a nested context in a previous context with reset on, we might continue to execute external code, reset
+            currentDeviceCache = -1;
+        }
+    }
+
+    const bool disableCache;
+    int lastDevice;
+
+
+public:
+    static int getDevice() {
+        int idx = -1;
+        if (cacheDisabled() || currentDeviceCache < 0) {
+            checkCUDA(cudaGetDevice(&idx));
+        } else {
+            idx = currentDeviceCache;
+        }
+        currentDeviceCache = cacheDisabled() ? -1 : idx;
+        return idx;
+    }
+private:
+    static void setDevice(int idx) {
+        // TODO: deal with stream when switching device
+        assert(idx >= 0);
+        if (!cacheDisabled() && currentDeviceCache == idx) {
+            return;
+        }
+        checkCUDA(cudaSetDevice(idx));
+        currentDeviceCache = cacheDisabled() ? -1 : idx;
+    }
+
+private:
+    static inline thread_local std::stack<CUDADeviceContext *> ctxs;
+    static inline thread_local int currentDeviceCache = -1;
+
+    static bool cacheDisabled() {
+        return ctxs.empty() || ctxs.top()->disableCache;
+    }
+};
+
 inline cudaDeviceProp *getCurrentDeviceProperties() {
-    static thread_local cudaDeviceProp prop;
-    static thread_local bool propAvailable = false;
-    if (!propAvailable) {
-        int device;
-        checkCUDA(cudaGetDevice(&device));
-        checkCUDA(cudaGetDeviceProperties(&prop, device));
-        propAvailable = true;
-    }
-    return &prop;
+    static thread_local std::map<int, cudaDeviceProp> props;
+
+    int deviceId = CUDADeviceContext::getDevice();
+    if (!props.contains(deviceId)) {
+        cudaDeviceProp prop;
+        checkCUDA(cudaGetDeviceProperties(&prop, deviceId));
+        props[deviceId] = prop;
+    }
+    return &props.at(deviceId);
 }
 
 template<typename T>

src/interop/torch.cpp

@@ -22,6 +22,7 @@ Tensor from_torch(at::Tensor input) {
     }
 
     static const std::map<at::ScalarType, Tensor::ScalarType> mapType = {
+        { at::ScalarType::Char, Tensor::INT8 },
         { at::ScalarType::Byte, Tensor::INT8 },
         { at::ScalarType::Int, Tensor::INT32 },
         { at::ScalarType::Long, Tensor::INT64 },
@@ -36,7 +37,7 @@ Tensor from_torch(at::Tensor input) {
     result.scalarType = mapType.at(input.scalar_type());
     result.buffer = std::make_shared<BufferTorchTensor>(std::move(input));
 
-    // Tensor::lockBuffer(result.buffer, getCurrentCUDAStream());
+    Tensor::lockBuffer(result.buffer, getCurrentCUDAStream());
 
     return result;
 }

src/interop/torch.h

@@ -15,7 +15,7 @@ public:
     }
     virtual bool isAsyncBuffer() override { 
         // TODO: figure out how torch manages memory
-        return true;
+        return this->device.type == Device::CUDA;
     }
 private:
     at::Tensor tensor;
@@ -30,4 +30,22 @@ public:
 };
 
 Tensor from_torch(at::Tensor input);
-at::Tensor to_torch(Tensor input);
+at::Tensor to_torch(Tensor input);
\ No newline at end of file
+
+class TensorsProviderTorch : public TensorsProvider {
+public:
+    TensorsProviderTorch(std::map<std::string, at::Tensor> dict) : storage(std::move(dict)) {}
+
+    virtual bool contains(const std::string &key) const override {
+        return storage.contains(key);
+    }
+    virtual Tensor getTensor(const std::string &key) override {
+        if (!storage.contains(key)) {
+            return Tensor{};
+        }
+        return from_torch(storage.at(key));
+    }
+
+private:
+    std::map<std::string, at::Tensor> storage;
+};
\ No newline at end of file