在gradle.properties，开启gradle单独的守护进程
同时这些参数也可以配置到前面的用户目录下的gradle.properties文件里，那样就不是针对一个项目生效，而是针对所有项目生效。
配置文件主要就是做， 增大gradle运行的java虚拟机的大小，让gradle在编译的时候使用独立进程，让gradle可以平行的运行。
# Project-wide Gradle settings.
# IDE (e.g. Android Studio) users:
# Settings specified in this file will override any Gradle settings
# configured through the IDE.
# For more details on how to configure your build environment visit
# http://www.gradle.org/docs/current/userguide/build_environment.html
# The Gradle daemon aims to improve the startup and execution time of Gradle.
# When set to true the Gradle daemon is to run the build.
# TODO: disable daemon on CI, since builds should be clean and reliable on servers
org.gradle.daemon=true
# Specifies the JVM arguments used for the daemon process.
# The setting is particularly useful for tweaking memory settings.
# Default value: -Xmx10248m -XX:MaxPermSize=256m
org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
# When configured, Gradle will run in incubating parallel mode.
# This option should only be used with decoupled projects. More details, visit
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
org.gradle.parallel=true
# Enables new incubating mode that makes Gradle selective when configuring projects.
# Only relevant projects are configured which results in faster builds for large multi-projects.
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:configuration_on_demand
org.gradle.configureondemand=truetasks.whenTaskAdded { task ->
if (task.name.equals("lint")) {
task.enabled = false
}
}这还是一个实验性的功能，但是还是推荐打开试试 在项目主Module下build.grade的Android中加入
dexOptions {
incremental true
}
这是官方的速度对比，据说下一代编译速度更快
Gradle对执行性能有很大的优化，但Android Studio现在默认使用的是Gradle 2.2, 所以我们需要手动让Android Studio使用Gradle，在项目根目录下的 build.grade中加入，如加入2.8
task wrapper(type: Wrapper) {
gradleVersion = '2.8'
}
然后打开终端执行 ./gradlew wrapper，就可以下载Gradle 2.8了，下载完成后，我们需要在Android Studio让我们的项目使用Gradle 2.8。
注意gradle和android gradle for android plugin版本对应
