Bharathi Ramana Joshi iambrj

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

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

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

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

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

How to Debug Chez Scheme Programs

R. Kent Dybvig

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.

Fundamentals

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


	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'

	# 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