The author asserts, that "it's virtually impossible to write allocation-free idiomatic Java code, so we still allocate... 20 bytes on average per forwarded packet". This sounds questionable, — does that mean, that he actually performs a JVM memory allocation for _every_ packet?! Furthermore, the specifics of memory management look murky. One implementation uses "volatile" C writes [1] (simply storing data to memory). Another implementations of the same thing uses a full CPU memory barrier [2]. Which one is right?
In my opinion, significant inconsistencies between implementations render any comparison between them invalid. And when a whole cross-language test suite is written by one person, you can be sure, that they don't really excel in many of those languages.
This is why I like Benchmark Game — all benchmarks are submitted by users, so they are a lot closer to how a real-world decent programmers can solve the problem. Still not perfect, but at least that counts as an attempt.
1: https://github.com/ixy-languages/ixy.java/blob/fcad50339e537...
2: https://github.com/ixy-languages/ixy.java/blob/fcad50339e537...