JB julienbenjamin

Raspberry Pi general optimization

Use a class 10 SD card for best speed. The USB bus can't come much higher than 30MB/s so you don't have to buy any extremely fast ones though. Not all cards are compatible, check the compatibility list: http://elinux.org/RPi_SD_cards
Use the HardFloat version of Raspbian instead of the SoftFloat. HF has much faster floating point operations - however SF is required for running Java. So it's either Java or performance, like normal.
The official Raspbian image gives low network speeds: http://elinux.org/RPi_Performance#NIC
A graphics driver by Simon / teh_orph is using hardware acceleration for some instructions: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=28294 installation instructions: http://elinux.org/RPi_Xorg_rpi_Driver
The firmware can be upgraded which gives, among other things, better GPU performance.

git cheat-sheet

The git command-line utility has plenty of inconsistencies http://steveko.wordpress.com/2012/02/24/10-things-i-hate-about-git/

A GUI like http://sourcetreeapp.com is often helpful, but staying on the command line usually quicker. This is a list of the commands I use most frequently, listed by functional category:

Current state

git status list which (unstaged) files have changed

To limit a CPU to a certain C-state, you can pass the processor.max_cstate=X option in the kernel line of /boot/grub/grub.conf.

Here we limit the system to only C-State 1:

    kernel /vmlinuz-2.6.18-371.1.2.el5 ... processor.max_cstate=1

On some systems, the kernel can override the BIOS setting, and the parameter intel_idle.max_cstate=0 may be required to ensure sleep states are not entered:

To remove a submodule you need to:

Delete the relevant section from the .gitmodules file.
Stage the .gitmodules changes git add .gitmodules
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Run rm -rf .git/modules/path_to_submodule (no trailing slash).
Commit git commit -m "Removed submodule "
Delete the now untracked submodule files rm -rf path_to_submodule

Don't use VPN services.

No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.

Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.

A Russian translation of this article can be found here, contributed by Timur Demin.
A Turkish translation can be found here, contributed by agyild.
There's also this article about VPN services, which is honestly better written (and has more cat pictures!) than my article.

Orthodox C++

What is Orthodox C++?

Orthodox C++ (sometimes referred as C+) is minimal subset of C++ that improves C, but avoids all unnecessary things from so called Modern C++. It's exactly opposite of what Modern C++ suppose to be.

	#!/usr/bin/perl

	# Ref: Calculating CPU Usage from /proc/stat
	# (http://colby.id.au/node/39)

	use strict;
	use warnings 'all';
	use utf8;

	use List::Util qw(sum);

	// this file is an example of how to intercept a C++ method by using the
	// LD_PRELOAD environment variable of the GNU dynamic linker.
	//
	// it works like this:
	//
	// 1) define a method that will have the same symbol as the intercepted
	// method when compiled. For example, the method Foo::getValue()
	// defined here has the mangled symbol "_ZNK3Foo8getValueEv".
	// tools like nm, objdump or readelf can display the symbols of
	// binaries. note that depending on compiler and linker options,

	#!/bin/bash

	# https://gist.github.com/robwierzbowski/5430952/
	# Create and push to a new github repo from the command line.
	# Grabs sensible defaults from the containing folder and `.gitconfig`.
	# Refinements welcome.

	# Gather constant vars
	CURRENTDIR=${PWD##*/}
	GITHUBUSER=$(git config github.user)

	10-Bit H.264

	For all those who haven’t heard of it already, here’s a quick rundown about the
	newest trend in making our encodes unplayable on even more systems: So-called
	high-bit-depth H.264. So, why another format, and what makes this stuff
	different from what you know already?

	First off: What is bit depth?
	In short, bit depth is the level of precision that’s available for storing color
	information. The encodes you’re used to have a precision of 8 bits (256 levels)