(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
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 |
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
#!/bin/sh | |
### | |
# SOME COMMANDS WILL NOT WORK ON macOS (Sierra or newer) | |
# For Sierra or newer, see https://github.com/mathiasbynens/dotfiles/blob/master/.macos | |
### | |
# Alot of these configs have been taken from the various places | |
# on the web, most from here | |
# https://github.com/mathiasbynens/dotfiles/blob/5b3c8418ed42d93af2e647dc9d122f25cc034871/.osx |
FILE SPACING: | |
# double space a file | |
sed G | |
# double space a file which already has blank lines in it. Output file | |
# should contain no more than one blank line between lines of text. | |
sed '/^$/d;G' |
This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).
Matrix multiplication is a mathematical operation that defines the product of
#!/bin/bash | |
# Might as well ask for password up-front, right? | |
sudo -v | |
# Keep-alive: update existing sudo time stamp if set, otherwise do nothing. | |
while true; do sudo -n true; sleep 60; kill -0 "$$" || exit; done 2>/dev/null & | |
# Example: do stuff over the next 30+ mins that requires sudo here or there. | |
function wait() { |
require 'rubygems' | |
require 'yaml' | |
# A demonstration of YAML anchors, references and handling of nested values | |
# For more info, see: | |
# http://atechie.net/2009/07/merging-hashes-in-yaml-conf-files/ | |
stooges = YAML::load( File.read('stooges.yml') ) | |
# => { | |
# "default" => { |