jboner

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

wumpz

git shortlog -e -s -n

nicowilliams

I recently happened upon a very interesting implementation of popen() (different API, same idea) called popen-noshell using clone(2), and so I opened an issue requesting use of vfork(2) or posix_spawn() for portability. It turns out that on Linux there's an important advantage to using clone(2). I think I should capture the things I wrote there in a better place. A gist, a blog, whatever.

This is not a paper. I assume reader familiarity with fork() in particular and Unix in general, though, of course, I link to relevant wiki pages, so if the unfamiliar reader is willing to go down the rabbit hole, they should be able to come ou

elizarov

import kotlin.coroutines.experimental.*
import kotlin.coroutines.experimental.intrinsics.*

fun main(args: Array<String>) {
    enumerate {
        if (flip("A")) {
            if (flip("B")) 1 else 2
        } else {
            if (flip("C")) 3 else if (flip("D")) 4 else 5
        }

AdelDima

# If you come from bash you might have to change your $PATH.
export PATH=$HOME/bin:/usr/local/bin:$PATH

# Path to your oh-my-zsh installation.
export ZSH=$HOME/.oh-my-zsh

# Set name of the theme to load. Optionally, if you set this to "random"
# it'll load a random theme each time that oh-my-zsh is loaded.
# See https://github.com/robbyrussell/oh-my-zsh/wiki/Themes
ZSH_THEME="agnoster"

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

kunalkushwaha

Software Versions

$ runc --version
runc version 1.0.0-rc4+dev
commit: f53ad9cec928821a25c2a74eb8bd95558f8cf152-dirty
spec: 1.0.0

$ containerd --version
containerd github.com/containerd/containerd v1.0.0-beta.3-86-g9649a42 9649a428e8c470cddc0d5a3c394f36111f940adc

rexlow

##
# This is an adoption from Oh My Zsh for Google Cloud Shell
# author - bobvanluijt
# source - https://github.com/bobvanluijt/google-cloud-shell-pro-zsh
##

main() {

  # Install zsh
  sudo apt-get -qq update 

abhijeet2096

%% Topic  : Binary Search Tree Implementation in Prolog 
%% Author : Abhijeet Sharma | Akhil Singhal
%% Date   : 26/03/2018
%% Course : Paradigms of Programming

%% Sample Inputs 

%% Input inl([3,6,1,2,4,7,9],nil,X).
%% X = t(3, t(1, nil, t(2, nil, nil)), t(6, t(4, nil, nil), t(7, nil, t(9, nil, nil))))

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