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

chetanmeh

source ~/path/to/tabs.sh

load-dev(){
    #Create sessi data format '<Tab Name/Title>    <Profile Name>   <Working Directory>'
    local sessions=(
        oak           Shell        'clear; cd ~/git/apache/oak'
        sling         Shell        'clear; cd ~/git/apache/sling'
        felix         Shell        'clear; cd ~/git/apache/felix'
     )
    start_sessions sessions[@]

cabal95

#!/bin/bash
#

BACKUPDEST="$1"
DOMAIN="$2"
MAXBACKUPS="$3"

if [ -z "$BACKUPDEST" -o -z "$DOMAIN" ]; then
    echo "Usage: ./vm-backup <backup-folder> <domain> [max-backups]"
    exit 1

null-dev

<?php
if(!isset($_GET['a'])) {
	die('<form action="" method="get"><input type="text" name="a"/><input type="submit"/></form>');
}

$url = "https://1fichier.com/?" . urlencode($_GET['a']) . "?auth=1&inline";
stream_context_set_default(array(
			'http' => array(
				'method' => 'GET',
				'header' => 'Authorization: Basic ' . '[BASE64 encoded login credentials. Format: "user:pass" (without quotes)]'

harrykipper

diff -rupN linux-4.10-orig/drivers/acpi/pci_root.c linux-4.10/drivers/acpi/pci_root.c
--- linux-4.10-orig/drivers/acpi/pci_root.c	2017-04-03 11:16:04.296665638 +0200
+++ linux-4.10/drivers/acpi/pci_root.c	2017-04-03 11:17:21.696665034 +0200
@@ -494,13 +494,13 @@ static void negotiate_os_control(struct
 			 * it's unsupported. Leave existing configuration
 			 * intact and prevent the OS from touching it.
 			 */
-			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
-			*no_aspm = 1;
+			dev_info(&device->dev, "FADT indicates ASPM is unsupported, not caring and keeping ASPM\n");

pigeonhill

--HHB Script Release 1.75

--[[
********************************************************************************************
This script attempts to capture 'the best' bracket sequence when hand holding.
The bracketing scheme is based on ISO shifting as well as time shifting.
The general strategy being to time shift from the highlights at the lowst ISO you can, and ISO shift from the shadows from the lowest Tv you can, at ISO 100. That is try and maximise photon capture, ie for the highest DR.
Note pushing ISO too far is pointless, as once above a critical level, Canon cameras go into ISO invariant zone (varies with camera) and overall DR falls with no increase in (read) noise.
You should also be high enough to be above the 'pattern noise', but not too high.
On a 5D3 a figure of 6400 seems to work well, on an EOSM, say, maybe try 1600 or 3200.

droM4X

#!/bin/bash
HOSTNAME=${COLLECTD_HOSTNAME:-localhost};
INTERVAL=${COLLECTD_INTERVAL:-60};

while sleep "$INTERVAL"
do

for filter in active all downloading
    do
	url="http://localhost:8080/api/v2/torrents/info?filter=$filter"

AndrewLipscomb

How to set up static nspawn IP address networking without a bridge

Note - this article assumes you have reasonable familiarity with systemd, networkd and nspawn/machinectl

What is this guide for

There seem to be a lot of references on the internet for nspawn networking with a bridge - but not on simply using the stock veth networking with static addresses. The default behaviour of nspawn (as of 24/03/20 and systemd:245 on Arch) is to:

• Make a virtual ethernet port on the host (defined by /lib/systemd/network/80-container-ve.network)
• Make a virtual ethernet port in the container (defined by /lib/systemd/network/80-container-host0.network)
• Based on those configurations, serve the host port a random IP from the local network ranges with a 28 bit subnet, and a DHCP server for the host port serves a random IP in the subnet to the container

aelk00

1- Go to: https://www.facebook.com/{your_id_or_username}/allactivity/?category_key=LIKEDPOSTS&filter_hidden=ALL&filter_privacy=NONE You can use Filter to choose year or month.
2- Open the console and run the following JavaScript code and wait:

setInterval(() => {
  for (const Button of document.querySelectorAll('div[aria-label="Action options"]')) {
    Button.click()
    document.querySelector('div[role="menuitem"]').click()
  }
}, 1000)

nicman23

#! /bin/bash -e
if [ -z "$1" ]; then
  echo 'usage: [OPTIONS] <file>|<dir>'
  echo 'same as btrfs filesystem defrag (look at its --help)'
  exit
fi
if [ ! "$(id -u)" -eq 0 ]; then
  echo 'This probably needs root, if not edit' "$0"
  echo 'Remove line 10: sed -e '\''10d'\'' -i' "$0"
  exit 2