While KDBUS tried to be included for Linux 4.1, it was ultimately rejected for this current Linux kernel development cycle. However, it looks like developers might be gearing up to try to push it into the Linux 4.2 kernel.

David Herrmann, one of the very active systemd and KDBUS developers, sent in a pull request today of KDBUS updates for Linux 4.2. The KDBUS cleanups for Linux 4.2 include changes for meta-data collection and management, translating CAPS between namespaces, notification changes, and other fixes/improvements.

In response, there's still more changes pending to speed-up KDBUS by several percent over its current form.

The KDBUS Git code continues to evolve, but it's still not clear yet whether it's in good enough shape to be accepted for the Linux 4.2 kernel as a new feature... We'll see in a few weeks time when Linux 4.2 gets underway.