add flashinfer to cuda device

doc/en/balance-serve.md

@@ -100,10 +100,8 @@ git submodule update --init --recursive
 
 # Install single NUMA dependencies
 USE_BALANCE_SERVE=1  bash ./install.sh
-pip install third_party/custom_flashinfer/
 # For those who have two cpu and 1T RAM（Dual NUMA）:
 USE_BALANCE_SERVE=1 USE_NUMA=1 bash ./install.sh
-pip install third_party/custom_flashinfer/
 ```
 
 ## Running DeepSeek-R1-Q4KM Models

doc/en/install.md

@@ -117,13 +117,11 @@ Download source code and compile:
 
     ```shell
     USE_BALANCE_SERVE=1 bash ./install.sh
-    pip install third_party/custom_flashinfer/
     ```
   - For Multi-concurrency with two cpu and 1T RAM:
 
     ```shell
     USE_BALANCE_SERVE=1 USE_NUMA=1 bash ./install.sh
-    pip install third_party/custom_flashinfer/
     ```
 - For Windows (Windows native temporarily deprecated, please try WSL)
 

doc/en/llama4.md

@@ -68,10 +68,8 @@ pip3 install torch torchvision torchaudio --index-url https://download.pytorch.o
 ```bash
 # Install single NUMA dependencies
 USE_BALANCE_SERVE=1  bash ./install.sh
-pip install third_party/custom_flashinfer/
 # For those who have two cpu and 1T RAM（Dual NUMA）:
 USE_BALANCE_SERVE=1 USE_NUMA=1 bash ./install.sh
-pip install third_party/custom_flashinfer/
 ```
 
 ### 4. Use our custom config.json

doc/zh/DeepseekR1_V3_tutorial_zh.md

@@ -127,10 +127,8 @@ cd ktransformers
 git submodule update --init --recursive
 # 如果使用双 numa 版本
 USE_BALANCE_SERVE=1 USE_NUMA=1 bash ./install.sh
-pip install third_party/custom_flashinfer/
 # 如果使用单 numa 版本
 USE_BALANCE_SERVE=1 bash ./install.sh
-pip install third_party/custom_flashinfer/
 # 启动命令
 python ktransformers/server/main.py --model_path <your model path> --gguf_path <your gguf path> --cpu_infer 62 --optimize_config_path <inject rule path> --port 10002 --chunk_size 256 --max_new_tokens 1024 --max_batch_size 4 --port 10002 --cache_lens 32768 --backend_type balance_serve
 ```

install.sh

@@ -38,6 +38,10 @@ fi
 echo "Installing ktransformers"
 KTRANSFORMERS_FORCE_BUILD=TRUE pip install -v . --no-build-isolation
 
+if [[ "$DEV_BACKEND" == "cuda" ]]; then
+    echo "Installing custom_flashinfer for CUDA backend"
+    pip install third_party/custom_flashinfer/
+fi
 # SITE_PACKAGES=$(python -c "import site; print(site.getsitepackages()[0])")
 # echo "Copying thirdparty libs to $SITE_PACKAGES"
 # cp -a csrc/balance_serve/build/third_party/prometheus-cpp/lib/libprometheus-cpp-*.so* $SITE_PACKAGES/