on by default.
The default is to wait after each counter is tested. Since the prompt
would go to stdout you won't see it if you're redirecting the output
of the executed sub-program to /dev/null, so just press return to
continue or Ctrl-D to stop.
system and then execute a program with pmcstat in counting mode.
The program will verify that all counters fire and that the code neither
panics the system nor locks it up. This should be considered a first pass
conformance test for new sets of counters being added to hwpmc(4).