Andrei Dragomir adragomir

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
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 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 4X memory

Operational PGP

This is a guide on how to email securely.

There are many guides on how to install and use PGP to encrypt email. This is not one of them. This is a guide on secure communication using email with PGP encryption. If you are not familiar with PGP, please read another guide first. If you are comfortable using PGP to encrypt and decrypt emails, this guide will raise your security to the next level.

Channels Are Not Enough

... or Why Pipelining Is Not That Easy

Golang Concurrency Patterns for brave and smart.

By @kachayev

Intro

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

http://mvdirona.com/jrh/talksandpapers/jamesrh_lisa.pdf

Basic tenets

Does the design expect failures to happen regularly and handle them gracefully?
Have we kept things as simple as possible?

	nnoremap <silent> y :<C-U>call MarkAndSetOpfunc()<CR>g@
	vnoremap <silent> y :<C-U>call MarkYankAndJump()<CR>

	function! MarkAndSetOpfunc()
	let g:save_cursor = getpos(".")
	set opfunc=YankAndJumpBack
	endfunction

	function! MarkYankAndJump()
	let g:save_cursor = getpos(".")

	OSX Apps
	- Total Spaces, for keeping X11 in different space and faster switching
	- MenuAndDockless for hidding topbar menu

	X11 - Macports
	- sudo port install xorg-server
	- sudo port install xinit
	- sudo port install terminus-font dejavu-fonts bitstream-fonts

	Suckless - suckless.org

	# /etc/fstab

	LABEL=cloudimg-rootfs / ext4 defaults 0 0
	/dev/xvdb /mnt/is0 auto defaults,nobootwait,comment=instancestore0 0 2
	/dev/xvdc /mnt/is1 auto defaults,nobootwait,comment=instancestore1 0 2
	/mnt/is0/tmp /tmp none bind,noauto 0 0
	/mnt/is0/var/tmp /var/tmp none bind,noauto 0 0

	(Chapters marked with * are already written. This gets reorganized constantly
	and 10 or so written chapters that I'm on the fence about aren't listed.)

	Programmer Epistemology
	* Dispersed Cost vs. Reduced Cost
	* Verificationist Fallacy
	* Mistake Metastasis
	The Overton Window
	Epicycles All The Way Down
	The Hyperspace Gates Were Just There

	require "erb"
	require "pathname"

	DOT_TEMPLATE=<<-END
	digraph {
	size="20,20";
	overlap=false;
	sep=0.4;
	graph [fontname=Helvetica,fontsize=10];
	node [fontname=Helvetica,fontsize=10];