What's new in the OpenJ9 project

Eclipse OpenJ9 version 0.26.0 released

April 2021

We're pleased to announce the availability of Eclipse OpenJ9 v0.26.0.

It's been little more than a month since our last release, which supported the OpenJDK 16 feature release. We can confirm that the following features first announced in OpenJ9 v0.25.0 are now available in OpenJ9 v0.26.0 for OpenJDK 8 and 11:

• For easier adoption and deployment, compressed and non-compressed object reference support is now combined in a single binary of OpenJDK with OpenJ9 0.26.0 rather than two distinct binaries (standard and large heap). The object reference mode is selected at run time based on the Java object heap size or by specifying the mode you want to use on the command line.
• Improved hardware acceleration is implemented for AIX systems that contain the Nest accelerator (NX) co-processor by using the zlibNX library.

Performance highlights

Eclipse OpenJ9 v0.26.0 also contains a number of performance improvements.

• When the OpenJ9 VM is run in debug mode, startup time is improved significantly. This achievement is possible because the JIT can now generate AOT-compiled code for this mode. The AOT-compiled code is stored in the shared classes cache and is transparently accessible to an application that uses the cache at startup.
• Throughput performance improvements of 10-20% are seen on AArch64 platforms due to the addition of inlined write barrier support.
• On OpenJDK 11 and later releases, improvements are made for String performance by fixing a JIT issue that enables an optimization for accelerating String concatenations.

To read more about the changes for v0.25.0 and v.0.26.0, see the OpenJ9 user documentation.