hellerbarde

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

ssstonebraker

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'

sloria

The Best of the Best Practices (BOBP) Guide for Python

A "Best of the Best Practices" (BOBP) guide to developing in Python.

In General

Values

• "Build tools for others that you want to be built for you." - Kenneth Reitz
• "Simplicity is alway better than functionality." - Pieter Hintjens

bertvv

# Generate PDFs from the Markdown source files
#
# In order to use this makefile, you need some tools:
# - GNU make
# - Pandoc
# - LuaLaTeX
# - DejaVu Sans fonts

# Directory containing source (Markdown) files
source := src

justbuchanan

This project has moved to https://github.com/justbuchanan/i3scripts

j-jith

How to flash MIUI Fastboot ROM from Linux

• Download the fastboot ROM suitable for your device from the MIUI site and extract the downloaded archive [edit: MIUI page is dead. Use Xiaomi Firmware Updater]
• Download and extract the Android SDK Platform Tools
• Make sure adb and fastboot (components of platform-tools) are in your

stereobooster

• http://blog.felipe.rs/2017/07/07/where-do-type-systems-come-from/
• http://tomasp.net/academic/papers/against-types/
• Against a universal definition of ‘type’
• The Triumph of Types: Principia Mathematica’s Impact on Computer Science
• Function and Concept
• https://www.cs.uoregon.edu/research/summerschool/summer15/curriculum.html

nadavrot

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

andregrigon

How to Debug Chez Scheme Programs

R. Kent Dybvig

August 2002

1. Basic debugging techniques
   1. Kinds of failure
   2. Understanding error messages
   3. Staring at the code
2. Simplifying the code and input

stettix

Things I believe

This is a collection of the things I believe about software development. I have worked for years building backend and data processing systems, so read the below within that context.

Agree? Disagree? Feel free to let me know at @JanStette. See also my blog at www.janvsmachine.net.

Fundamentals

Keep it simple, stupid. You ain't gonna need it.