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chendotjs / latency.txt
Created March 29, 2024 01:48 — forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
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
@chendotjs
chendotjs / sysctl.conf
Created April 1, 2021 07:50 — forked from voluntas/sysctl.conf
Sysctl configuration for high performance
### KERNEL TUNING ###
# Increase size of file handles and inode cache
fs.file-max = 2097152
# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2
@chendotjs
chendotjs / simple-drop-kp.bt
Last active January 14, 2021 06:05 — forked from florianl/flow.bt
simple bpftrace script to print out drop packet
#!/bin/bpftrace
#include <linux/skbuff.h>
#include <linux/ip.h>
BEGIN
{
printf("follow the white rabbit\n");
}