Malisa malisas

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

Markdown and reStructuredText

GitHub supports several lightweight markup languages for documentation; the most popular ones (generally, not just at GitHub) are Markdown and reStructuredText. Markdown is sometimes considered easier to use, and is often preferred when the purpose is simply to generate HTML. On the other hand, reStructuredText is more extensible and powerful, with native support (not just embedded HTML) for tables, as well as things like automatic generation of tables of contents.

	<?
	/////////////////////
	// slack2html
	// by @levelsio
	/////////////////////
	//
	/////////////////////
	// WHAT DOES THIS DO?
	/////////////////////
	//

	sudo apt-get remove scala-library scala
	sudo wget www.scala-lang.org/files/archive/scala-2.10.4.deb
	sudo dpkg -i scala-2.10.4.deb
	sudo apt-get update
	sudo apt-get install scala
	wget http://scalasbt.artifactoryonline.com/scalasbt/sbt-native-packages/org/scala-sbt/sbt/0.12.4/sbt.deb
	sudo dpkg -i sbt.deb
	sudo apt-get update
	sudo apt-get install sbt