Steven Yan wenshin

程序员都应该知道的延迟时间

CPU L1 缓存引用 .......................... 0.5 ns
CPU 分支错误预测 ............................ 5 ns
CPU L2 缓存引用 ............................ 7 ns
互斥锁 加锁/解锁 ........................... 25 ns
内存引用 ................................. 100 ns             
Zip 压缩 1K bytes ..................... 3,000 ns  =   3 µs
1 Gbps 网络发送 2K bytes .............. 20,000 ns  =  20 µs
SSD 随机读 ........................... 150,000 ns  = 150 µs

内存连续读 1 MB 数据 .................. 250,000 ns = 250 µs

	#!/bin/sh

	##
	# Install autoconf, automake and libtool smoothly on Mac OS X.
	# Newer versions of these libraries are available and may work better on OS X
	#
	# This script is originally from http://jsdelfino.blogspot.com.au/2012/08/autoconf-and-automake-on-mac-os-x.html
	#

	export build=~/devtools # or wherever you'd like to build