Re: How to measure performance inside Kernel?

Hi! On 19:47 Fri 10 Feb , Peter Senna Tschudin wrote: ...

#include <linux/time.h>

getnstimeofday (ts_start); /*stopwatch start*/ ... getnstimeofday (ts_end); /*stopwatch stop*/

diff = timespec_sub(end, begin);

printk ("%lu,", diff.tv_nsec );

Am I doing anything wrong? Can mysterious stuff like out of order execution engine, brake the stopwatch?

Why don't you print the tv_sec part? You might also want to replace getnstimeofday with getrawmonotonic or any other monotonic time source. If ntp or something else decides to change system time during the measurement, you would probably get weird results. -Michi -- programing a layer 3+4 network protocol for mesh networks see http://michaelblizek.twilightparadox.com