The regular LWN kernel development stats have been posted here for version 4.1 (if you really don’t have a subscription, email me for a free link). In this, Jon Corbet notes:
over 60% of the changes going into this kernel passed through the hands of developers working for just five companies. This concentration reflects a simple fact: while many companies are willing to support developers working on specific tasks, the number of companies supporting subsystem maintainers is far smaller. Subsystem maintainership is also, increasingly, not a job for volunteer developers..
As most folks reading this would know, I lead the mainline Linux Kernel team at Oracle. We do have several people on the team who work in leadership roles in the kernel community (myself included), and what I’d like to make clear is that we are actively looking to support more such folk.
If you’re a subsystem maintainer (or acting in a comparable leadership role), please always feel free to contact me directly via email to discuss employment possibilities. You can also contact Oracle kernel folk who may be presenting or attending Linux conferences.