lalyos

The new Docker daemon uses port: 2376 with TLS enable by default. Sometimes I want to play with curl on the old plain http port 2375. The trick is: use socat in a container to proxy the unix socket to a real port.

docker run -d \
  --volume /var/run/docker.sock:/var/run/docker.sock \
  --name docker-http \
  deb socat -d -d TCP-L:2375,fork UNIX:/var/run/docker.sock

probonopd

#include <IRremote.h>

/*

 Send infrared commands from the Arduino to the iRobot Roomba
 by probono
 
 2013-03-17 Initial release
 

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

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