Microsecond accurate (or better) process timing in Linux

Question

I need a very accurate way to time parts of my program. I could use the regular high-resolution clock for this, but that will return wallclock time, which is not what I need

Answer 1

try the CPU's timestamp counter? Wikipedia seems to suggest using clock_gettime().

Answer 2

If you need very small time units to for (I assume) testing the speed of your software, I would reccomend just running the parts you want to time in a loop millions of times, take the time before and after the loop and calculate the average. A nice side-effect of doing this (apart from not needing to figure out how to use nanoseconds) is that you would get more consistent results because the random overhead caused by the os sceduler will be averaged out.

Of course, unless your program doesn't need to be able to run millions of times in a second, it's probably fast enough if you can't measure a millisecond running time.