[doc] updated installation command (#5389)

README.md

@@ -398,10 +398,10 @@ pip install colossalai
 
 **Note: only Linux is supported for now.**
 
-However, if you want to build the PyTorch extensions during installation, you can set `CUDA_EXT=1`.
+However, if you want to build the PyTorch extensions during installation, you can set `BUILD_EXT=1`.
 
 ```bash
-CUDA_EXT=1 pip install colossalai
+BUILD_EXT=1 pip install colossalai
 ```
 
 **Otherwise, CUDA kernels will be built during runtime when you actually need them.**
@@ -429,7 +429,7 @@ By default, we do not compile CUDA/C++ kernels. ColossalAI will build them durin
 If you want to install and enable CUDA kernel fusion (compulsory installation when using fused optimizer):
 
 ```shell
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
 For Users with CUDA 10.2, you can still build ColossalAI from source. However, you need to manually download the cub library and copy it to the corresponding directory.
@@ -445,7 +445,7 @@ unzip 1.8.0.zip
 cp -r cub-1.8.0/cub/ colossalai/kernel/cuda_native/csrc/kernels/include/
 
 # install
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
 <p align="right">(<a href="#top">back to top</a>)</p>

docs/source/en/get_started/installation.md

@@ -23,7 +23,7 @@ pip install colossalai
 If you want to build PyTorch extensions during installation, you can use the command below. Otherwise, the PyTorch extensions will be built during runtime.
 
 ```shell
-CUDA_EXT=1 pip install colossalai
+BUILD_EXT=1 pip install colossalai
 ```
 
 
@@ -39,7 +39,7 @@ cd ColossalAI
 pip install -r requirements/requirements.txt
 
 # install colossalai
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
 If you don't want to install and enable CUDA kernel fusion (compulsory installation when using fused optimizer), just don't specify the `CUDA_EXT`:
@@ -61,7 +61,7 @@ unzip 1.8.0.zip
 cp -r cub-1.8.0/cub/ colossalai/kernel/cuda_native/csrc/kernels/include/
 
 # install
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
 <!-- doc-test-command: echo "installation.md does not need test" -->

docs/source/zh-Hans/get_started/installation.md

@@ -20,10 +20,10 @@ pip install colossalai
 
 **注：现在只支持Linux。**
 
-如果你想同时安装PyTorch扩展的话，可以添加`CUDA_EXT=1`。如果不添加的话，PyTorch扩展会在运行时自动安装。
+如果你想同时安装PyTorch扩展的话，可以添加`BUILD_EXT=1`。如果不添加的话，PyTorch扩展会在运行时自动安装。
 
 ```shell
-CUDA_EXT=1 pip install colossalai
+BUILD_EXT=1 pip install colossalai
 ```
 
 ## 从源安装
@@ -38,10 +38,10 @@ cd ColossalAI
 pip install -r requirements/requirements.txt
 
 # install colossalai
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
-如果您不想安装和启用 CUDA 内核融合（使用融合优化器时强制安装），您可以不添加`CUDA_EXT=1`：
+如果您不想安装和启用 CUDA 内核融合（使用融合优化器时强制安装），您可以不添加`BUILD_EXT=1`：
 
 ```shell
 pip install .
@@ -60,7 +60,7 @@ unzip 1.8.0.zip
 cp -r cub-1.8.0/cub/ colossalai/kernel/cuda_native/csrc/kernels/include/
 
 # install
-CUDA_EXT=1 pip install .
+BUILD_EXT=1 pip install .
 ```
 
 <!-- doc-test-command: echo "installation.md does not need test" -->