Update the installation of MMCV (#1226)

.github/workflows/build.yml

@@ -41,22 +41,22 @@ jobs:
         torch: [1.5.0+cu101, 1.6.0+cu101, 1.7.0+cu101, 1.8.0+cu101]
         include:
           - torch: 1.5.0+cu101
-            torch_version: torch1.5.0
+            torch_version: torch1.5
             torchvision: 0.6.0+cu101
             mmcv_link: "torch1.5.0"
             cuda_arch: "7.0"
           - torch: 1.6.0+cu101
-            torch_version: torch1.6.0
+            torch_version: torch1.6
             mmcv_link: "torch1.6.0"
             torchvision: 0.7.0+cu101
             cuda_arch: "7.0"
           - torch: 1.7.0+cu101
-            torch_version: torch1.7.0
+            torch_version: torch1.7
             mmcv_link: "torch1.7.0"
             torchvision: 0.8.1+cu101
             cuda_arch: "7.0"
           - torch: 1.8.0+cu101
-            torch_version: torch1.8.0
+            torch_version: torch1.8
             mmcv_link: "torch1.8.0"
             torchvision: 0.9.0+cu101
             cuda_arch: "7.0"

docs/en/getting_started.md

@@ -84,6 +84,13 @@ Please replace `{cu_version}` and `{torch_version}` in the url to your desired o
 pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu110/torch1.7.0/index.html
 ```
 
+mmcv-full is only compiled on PyTorch 1.x.0 because the compatibility usually holds between 1.x.0 and 1.x.1. If your PyTorch version is 1.x.1, you can install mmcv-full compiled with PyTorch 1.x.0 and it usually works well.
+
+```shell
+# We can ignore the micro version of PyTorch
+pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu110/torch1.7/index.html
+```
+
 See [here](https://github.com/open-mmlab/mmcv#install-with-pip) for different versions of MMCV compatible to different PyTorch and CUDA versions.
 Optionally, you could also build the full version from source:
 

docs/zh_cn/getting_started.md

@@ -76,6 +76,13 @@ pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/{cu_version}/{
 pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu110/torch1.7.0/index.html
 ```
 
+PyTorch 在 1.x.0 和 1.x.1 之间通常是兼容的，故 mmcv-full 只提供 1.x.0 的编译包。如果你的 PyTorch 版本是 1.x.1，你可以放心地安装在 1.x.0 版本编译的 mmcv-full。
+
+```
+# 我们可以忽略 PyTorch 的小版本号
+pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu110/torch1.7/index.html
+```
+
 请参考 [MMCV](https://mmcv.readthedocs.io/en/latest/#installation) 获取不同版本的 MMCV 所兼容的的不同的 PyTorch 和 CUDA 版本。同时，也可以通过以下命令行从源码编译 MMCV：
 
 ```shell