TensorFlow Python2.7环境下的源码编译(二)安装配置
源代码树的根目录中包含了一个名为 configure 的 bash 脚本。
$ ./configure
接下来，配置系统会给出各种询问，以确认编译时的配置参数。
一、重要参数解释
Do you wish to build TensorFlow with jemalloc as malloc support? [Y/n]:
jemalloc as malloc support will be enabled for TensorFlow.
上面的选项表示是否使用jemalloc代替传统的malloc来管理内存？Jemalloc是杰森·埃文斯（Jason Evans）于2006年开发的用以取代传统低性能的malloc内存管理模块而开发的一款内存管理模块[4]。埃文斯并非等闲之辈，他是FreeBSD项目（一种类UNIX操作系统）的重要维护者之一。
Jemalloc先被Firefox浏览器采用，后来又被Facebook在其自己的各类应用上广泛使用，一战成名。好技术当然要用！直接按回车，确认默认值Y。
Do you wish to build TensorFlow with Google Cloud Platform support? [Y/n]: n
No Google Cloud Platform support will be enabled for TensorFlow.
这个选项是询问是否采用Google云平台来支持TensorFlow。这个云平台国内通常无法访问，建议输入“n”。有条件的读者，可直接按回车确认使用。
Do you wish to build TensorFlow with Hadoop File System support? [Y/n]: n
No Hadoop File System support will be enabled for TensorFlow.
这个选项是询问是否使用Hadoop 文件系统（HDFS）来支持TensorFlow。如果搭建了Hadoop集群，有读取HDFS数据需求的用户，可以回车确认。如果没有需求，手动输入“n”。
Do you wish to build TensorFlow with Amazon S3 File System support? [Y/n]: n
No Amazon S3 File System support will be enabled for TensorFlow.
类似的，这个选项是询问TensorFlow是否支持亚马逊的S3文件系统。读者根据自己的需要来确定“Y”或“n”。如果用不着，建议选择“n”。
Do you wish to build TensorFlow with Apache Kafka Platform support? [y/N]:
No Apache Kafka Platform support will be enabled for TensorFlow.
Kafka是由Apache软件基金会开发的一个开源流处理平台，是一种高吞吐量的分布式发布订阅消息系统。如果没有这个需要，建议选择默认值“N”。
Do you wish to build TensorFlow with XLA JIT support? [y/N]: n
No XLA JIT support will be enabled for TensorFlow.
这个选项是询问是否开启XLA JIT编译支持。XLA（Accelerated Linear Algebra/加速线性代数）目前还是TensorFlow的实验项目，XLA 使用 JIT（Just in Time，即时编译）技术来分析用户在运行时（runtime）创建的 TensorFlow 图，专门用于实际运行时的维度和类型。作为新技术，这项编译技术还不成熟，爱折腾的“极客”读者可以选“y”，否则选择默认值“N”。
Do you wish to build TensorFlow with CUDA support? [y/N]:
No CUDA support will be enabled for TensorFlow.
这个选项是询问是否使用CUDA。CUDA是一种由NVIDIA推出的通用并行计算架构，该架构使GPU能够解决复杂的计算问题。如果用户配备有NVIDIA的GPU，可以选择“y”，如果仅使用TensorFlow的CPU版本，回车确认“N”。
Do you wish to build TensorFlow with MPI support? [y/N]:
No MPI support will be enabled for TensorFlow.
这个选项是询问是否使用MPI。MPI(Message-Passing-Interface 消息传递接口)是实现进程级别的并行程序的通信协议，它通过在进程之间进行消息传递。如果不是基于TensorFlow做并行程序开发，建议回车确认选择默认值“N”。
Please specify optimization flags to use during compilation when bazel option "--config=opt" is specified [Default is -march=native]:
这个选项是指定CPU编译优化选项。默认值就是“-march=native”。这里“m”表示“machine（机器）”，“arch”就是“architecture”简写。“march”合在一起表示机器的结构，如果选择“-march=native”，则表示选择本地（native）CPU，如果本地CPU比较高级，就可以支持SSE4.2、AVX等选项。这里建议选择默认值。
Would you like to interactively configure ./WORKSPACE for Android builds? [y/N]:
这个选项是问是否进入Android的工作空间配置，如果不用手机版的TensorFlow开发，则选择默认值“N”。
之后，当显示“Configuration finished”（配置完成）字样，则表示配置顺利完成。
二、在同一个源代码树中的不同配置之间进行切换时运行 bazel clean。
三、实际配置全过程
➜ tensorflow git:(master) ./configure
WARNING: Running Bazel server needs to be killed, because the startup options are different.
WARNING: --batch mode is deprecated. Please instead explicitly shut down your Bazel server using the command "bazel shutdown".
You have bazel 0.15.2-homebrew installed.
Please specify the location of python. [Default is /usr/local/opt/python@2/bin/python2.7]:
Found possible Python library paths:
/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
Please input the desired Python library path to use. Default is [/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages]
Do you wish to build TensorFlow with Google Cloud Platform support? [Y/n]: n
No Google Cloud Platform support will be enabled for TensorFlow.
Do you wish to build TensorFlow with Hadoop File System support? [Y/n]: n
No Hadoop File System support will be enabled for TensorFlow.
Do you wish to build TensorFlow with Amazon AWS Platform support? [Y/n]: n
No Amazon AWS Platform support will be enabled for TensorFlow.
Do you wish to build TensorFlow with Apache Kafka Platform support? [Y/n]: n
No Apache Kafka Platform support will be enabled for TensorFlow.
Do you wish to build TensorFlow with XLA JIT support? [y/N]: n
No XLA JIT support will be enabled for TensorFlow.
Do you wish to build TensorFlow with GDR support? [y/N]: n
No GDR support will be enabled for TensorFlow.
Do you wish to build TensorFlow with VERBS support? [y/N]: n
No VERBS support will be enabled for TensorFlow.
Do you wish to build TensorFlow with OpenCL SYCL support? [y/N]: n
No OpenCL SYCL support will be enabled for TensorFlow.
Do you wish to build TensorFlow with CUDA support? [y/N]: n
No CUDA support will be enabled for TensorFlow.
Do you wish to download a fresh release of clang? (Experimental) [y/N]: n
Clang will not be downloaded.
Do you wish to build TensorFlow with MPI support? [y/N]: n
No MPI support will be enabled for TensorFlow.
Please specify optimization flags to use during compilation when bazel option "--config=opt" is specified [Default is -march=native]:
Would you like to interactively configure ./WORKSPACE for Android builds? [y/N]: n
Not configuring the WORKSPACE for Android builds.
Preconfigured Bazel build configs. You can use any of the below by adding "--config=<>" to your build command. See tools/bazel.rc for more details.
--config=mkl # Build with MKL support.
--config=monolithic # Config for mostly static monolithic build.
Configuration finished
