目录
主页：
https://github.com/uber/horovod
例如：
/home/work/tools/python-2.7.8-tf1.4-gpu
下载地址： https://www.open-mpi.org/software/ompi/v3.0/
解压后
./configure --prefix=/home/work/tools/openmpi
make && make install
确保PATH里有gcc48，以及/home/work/tools/openmpi/bin/
如果是GPU的，确保export LD_LIBRARY_PATH=/home/work/cudnnv6/cuda/lib64/:$LD_LIBRARY_PATH
因为安装时要用到-lpython2.7，如果没有root权限，去报错的gcc命令里找-L的路径，发现最简单粗暴的方法就是
cp /home/work/tools/python-2.7.8-tf1.4-gpu/lib/libpython2.7.so* /home/work/tools/openmpi/lib
或者
cp /home/work/tools/python-2.7.8-tf1.4-gpu/lib/ /home/work/tools/python-2.7.8-tf1.4-gpu/lib/python2.7/site-packages/tensorflow
然后pip安装：
/home/work/tools/python-2.7.8-tf1.4-gpu/bin/python /home/work/tools/python-2.7.8-tf1.4-gpu/bin/pip install horovod