Thibault Charbonnier thibaultcha

Nimrod Notes

Links

Reference

How to have local versions of tracked config files in git

This is a fairly common question, and there isn't a One True Answer.

These are the most common techniques:

If you can modify your application

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

	echo 'export PATH=$HOME/local/bin:$PATH' >> ~/.bashrc
	. ~/.bashrc
	mkdir ~/local
	mkdir ~/node-latest-install
	cd ~/node-latest-install
	curl http://nodejs.org/dist/node-latest.tar.gz \| tar xz --strip-components=1
	./configure --prefix=~/local
	make install # ok, fine, this step probably takes more than 30 seconds...
	curl https://www.npmjs.org/install.sh \| sh

	#!/bin/sh
	# ------------------------------------------------------------------------------
	# SOME INFOS : fairly standard (debian) init script.
	# Note that node doesn't create a PID file (hence --make-pidfile)
	# has to be run in the background (hence --background)
	# and NOT as root (hence --chuid)
	#
	# MORE INFOS : INIT SCRIPT http://www.debian.org/doc/debian-policy/ch-opersys.html#s-sysvinit
	# INIT-INFO RULES http://wiki.debian.org/LSBInitScripts
	# INSTALL/REMOVE http://www.debian-administration.org/articles/28

	package forma;

	import forma.WholeFileInputFormat;
	import cascading.scheme.Scheme;
	import cascading.tap.Tap;
	import cascading.tuple.Fields;
	import cascading.tuple.Tuple;
	import cascading.tuple.TupleEntry;
	import java.io.IOException;
	import org.apache.hadoop.mapred.JobConf;

	vendor(prop, args)
	-webkit-{prop} args
	-moz-{prop} args
	-ms-{prop} args
	-o-{prop} args
	{prop} args

	border-radius()
	vendor('border-radius', arguments)

	/*
	File: KeychainItemWrapper.h
	Abstract:
	Objective-C wrapper for accessing a single keychain item.

	Version: 1.2 - ARCified

	Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple
	Inc. ("Apple") in consideration of your agreement to the following
	terms, and your use, installation, modification or redistribution of

	for (var i = 0; i < 1024 * 1024; i++) {
	process.nextTick(function () { Math.sqrt(i) } )
	}

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD