Supported and Tested on FreeBSD 13 on Intel x86 (64-bit mode)

Building:
# scons

Cleaning:
# scons -c

Measure the pthread_kill and end-to-end signal latency
# ./ipitest

Measure the local exception latency (int3)
# ./sigtest

Both of the previous programs are in units of cycles while DTrace reports units 
of nanoseconds, convert by reading the TSC frequency from sysctl.
# sysctl machdep.tsc_freq"

You can breakdown the kernel timing using DTrace.  Given the low cost of some 
of the functions the DTrace FBT probes add measureable error.  I would run with 
and without to see how much overheads the probes add.

Run the following command while running the ipitest above
# ./ipi.d