Kazuhiro Konno has been an active contributor to the Eclipse OpenJ9 project since 2017. He has deep knowledge of both the ARMv7 and ARMv8 instruction set architectures and environments hosted on ARM processors. While his early contributions to OpenJ9 were fixes to the 32-bit ARM just-in-time (JIT) compiler, Konno-san's primary contribution to the OpenJ9 project is a port of the OpenJ9 Java Virtual Machine (JVM) to the AArch64 architecture, functionally completed and committed in early 2019. He successfully ported and committed key components such as the port library, interpreter, garbage collector, shared classes cache, class libraries, and build configuration and makefiles to build and run natively on AArch64. He has also contributed a Docker file and documentation describing how to build and configure OpenJ9 for AArch64. Of late, he has made a number of contributions toward providing a functional JIT compiler for AArch64. These commits involve extending the Eclipse OMR compiler for AArch64 (which he was instrumental in developing) to provide the needed functionality for Java, and developing the JIT runtime that is the interface between JITed code and the JVM. As a result of his many development contributions, Konno-san has acquired deep skills in different OpenJ9 components, especially the JIT compiler and runtime. The Eclipse OpenJ9 project would benefit from a committer with this depth of experience.
Konno-san has contributed over 114 pull requests to the project, and has repeatedly demonstrated thoroughness in his implementation and quality of those commits. He has also participated in the review of 21 pull requests from other contributors. His comments always reflect respect for contributors and professionalism. When his ARM expertise is explicitly sought during a code review or through a question on Slack in the community workspace, his responses are timely and helpful.
I believe Konno-san is an excellent candidate to be a committer in the Eclipse OpenJ9 project.