mashingan

Source: man syscall

Architecture calling conventions

Every architecture has its own way of invoking and passing arguments to the kernel. The details for various architectures are listed in the two tables below.

The first table lists the instruction used to transition to kernel mode, (which might not be the fastest or best way to transition to

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Orthodox C++

This article has been updated and is available here.

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

	;; Simple TCP echo server in x86_64 assembly, using Linux syscalls
	;;
	;; nasm -felf64 -o server.o server.asm
	;; ld server.o -o server
	;; ./server
	;;

	global _start

	;; Data definitions

	// Traverses an arbitrary struct and translates all stings it encounters
	//
	// I haven't seen an example for reflection traversing an arbitrary struct, so
	// I want to share this with you. If you encounter any bugs or want to see
	// another example please comment.
	//
	// The MIT License (MIT)
	//
	// Copyright (c) 2014 Heye Vöcking
	//

	package main

	import (
	"bytes"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"os"

	#!/bin/bash
	### BEGIN INIT INFO
	# Provides: <service name>
	# Required-Start: $remote_fs $syslog
	# Required-Stop: $remote_fs $syslog
	# Default-Start: 2 3 4 5
	# Default-Stop: 0 1 6
	# Short-Description: <service description>
	### END INIT INFO

	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

	wget --no-check-certificate --content-disposition https://github.com/joyent/node/tarball/v0.7.1
	# --no-check-cerftificate was necessary for me to have wget not puke about https
	curl -LJO https://github.com/joyent/node/tarball/v0.7.1