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Latency Comparison Numbers

Note: "Forked" from Latency Numbers Every Programmer Should Know

Event Nanoseconds Microseconds Milliseconds Comparison
L1 cache reference 0.5 - - -
Branch mispredict 5.0 - - -
L2 cache reference 7.0 - - 14x L1 cache
Mutex lock/unlock 25.0 - - -

Keybase proof

I hereby claim:

  • I am lenciel on github.
  • I am lenciel ( on keybase.
  • I have a public key ASAdpEB6qCAu--QM2AurwajcSOdLJ0NCda7NCK9RYsX6iAo

To claim this, I am signing this object:

lenciel / supervisord.conf
Created September 4, 2014 16:03
supervisor configuration file for sentry
; - Shell expansion ("~" or "$HOME") is not supported. Environment
; variables can be expanded using this syntax: "%(ENV_HOME)s".
; - Comments must have a leading space: "a=b ;comment" not "a=b;comment".
; Put this file in /etc/supervisord.conf
file=/tmp/supervisor.sock ; (the path to the socket file)
lenciel / supervisord
Created September 4, 2014 14:41
/etc/init.d/ script for supervisor on ubuntu
#! /bin/sh
# Makre sure you have the correct path set for:
# DAEMON=/usr/local/bin/supervisord
# SUPERVISORCTL=/usr/local/bin/supervisorctl
# Provides: supervisor
# Required-Start: $remote_fs $network $named
lenciel /
Created September 4, 2014 14:37
sentry configuration file
# This is the configuration file for sentry used by
# It's actually nothing special but a django settings file so you may put items like "ALLOWED_HOSTS" in it.
from sentry.conf.server import *
import os.path
CONF_ROOT = os.path.dirname(__file__)
lenciel / autossh.lenciel.plist
Last active December 6, 2022 07:59
autossh plist file
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">
lenciel / _syntax.diff
Last active August 29, 2015 14:01
diff before and after gist render sass fix
diff --git a/46501e4:sass/partials/_syntax.scss b/02b0441:sass/partials/_syntax.scss
index 137d475..5465286 100644
--- a/46501e4:sass/partials/_syntax.scss
+++ b/02b0441:sass/partials/_syntax.scss
@@ -22,10 +22,6 @@
@include border-radius(0);
-.line-data {
- font-size: 13px;


  • 计算机软硬件基础
  • 计算机网络
  • 操作系统
  • 数据结构和算法
  • 设计模式
  • 以及其他各种你应该懂的东西


  • 前端标准/规范
lenciel / Useful netcat examples on
Last active February 16, 2024 04:12
Useful netcat examples on Linux

Often referred to as the "swiss army of knife" for TCP/IP networking, [Netcat][1] is an extremely versatile Linux utility that allows you to do anything under the sun using TCP/UDP sockets. It is one of the most favorite tools for system admins when they need to do networking related troubleshooting and experimentation.

In this tutorial, I am sharing a few useful netcat examples, although the sky is the limit when it comes to possible netcat use cases. If you are using netcat regularly, feel free to share your use case.

Note that when you are binding to well-known ports (0-1023) with nc, you need root privilege. Otherwise, run nc as a normal user.

1. Test if a particular TCP port of a remote host is open.

$ nc -vn 5000
lenciel / vertical align
Created January 15, 2014 18:19
vertical align anything
%vertical-align {
position: relative;
top: 50%;
-webkit-transform: translateY(-50%);
-ms-transform: translateY(-50%);
transform: translateY(-50%);
.element p {
@extend %vertical-align;