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

appden

# put this in your bash profile (change the line below if you use .bash_profile)

# refresh profile on USR1 signal
trap 'eval $(PATH= /usr/libexec/path_helper -s) && source ~/.profile' USR1

# send USR1 signal to all bash instances
reload() {
	ps -xo pid,command | grep ' \-bash' | awk '{print $1}' | while read pid; do
		kill -USR1 $pid
	done