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@jboner
jboner / latency.txt
Last active May 6, 2024 07:06
Latency Numbers Every Programmer Should Know
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
@staltz
staltz / introrx.md
Last active May 6, 2024 01:44
The introduction to Reactive Programming you've been missing
@brandonb927
brandonb927 / osx-for-hackers.sh
Last active May 5, 2024 13:30
OSX for Hackers: Yosemite/El Capitan Edition. This script tries not to be *too* opinionated and any major changes to your system require a prompt. You've been warned.
#!/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
@ssstonebraker
ssstonebraker / sed cheatsheet
Created August 2, 2013 14:06 — forked from un33k/sed cheatsheet
Sed Cheatsheet
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'
@nadavrot
nadavrot / Matrix.md
Last active May 5, 2024 08:37
Efficient matrix multiplication

High-Performance Matrix Multiplication

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).

Intro

Matrix multiplication is a mathematical operation that defines the product of

@bishboria
bishboria / springer-free-maths-books.md
Last active April 25, 2024 06:27
Springer made a bunch of books available for free, these were the direct links
@asukakenji
asukakenji / 0-go-os-arch.md
Last active April 24, 2024 06:51
Go (Golang) GOOS and GOARCH

Go (Golang) GOOS and GOARCH

All of the following information is based on go version go1.17.1 darwin/amd64.

GOOS Values

GOOS Out of the Box
aix
android
@cowboy
cowboy / sudo-keepalive-example.sh
Created July 15, 2012 20:55
Bash: Sudo keep-alive (good for long-running scripts that need sudo internally but shouldn't be run with sudo)
#!/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() {
@bowsersenior
bowsersenior / stooge_loader.rb
Created May 18, 2011 23:18
A demo of YAML anchors, references and nested values
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" => {