This is a jitter benchmark based on the hourglass published by John Regehr, 2002.

John Regehr: "Inferring Scheduling Behavior with Hourglass". Proceedings of the 2002 USENIX Technical Conference FREENIX Track. Online.

The code is C11 and warning-free (except unused parameters) and should be compatible with UNIX systems. Tested only on Linux (OpenSUSE 13.1).

The calibration (ticks per second of the CPU's time-stamp counter) is not very stable. This could be due to the power governor changing the frequency during run-time. The program should be executed in the performance mode. So far, this is not implemented in the setup. For all CPUs, issue (as root):

:::bash
# echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

(Undo with ondemand or whatever was in these files before.)

Georg Wassen georg.wassen@gmail.com