Sometimes benchmark tests may need to output some useful information per trial, per iteration or per invocation (given the known issues with that) that augments the JMH output for warmups and iterations.

It's easy to use System.out.println but that will ignore the JMH verbosity option and may not line up very well with JMHs own output.

Perhaps it should be possible to obtain a PrintWriter so the benchmark can log it's own information, in addition to the verbosity level.