Following mainline with PREEMPT_RT

This proposal has been accepted as a session.


One Line Summary

Pitfalls you step in while porting PREEMPT_RT to a new mainline version.


The -RT patch is an out-of-tree patch and contains currently roughly about 300 individual patches. Porting them from one major Linux release to another is a challenging work. There are usually a lot of changes in the core code between one release to another. Those changes are usually transparent to the remaining part of the kernel. Even if functions are removed, then the remaining in-tree code is updated.
For the -RT patchset however, this means that someone has to look at this changes and see how to integrate them within the -RT patch. Since the -RT patch touches every critical piece of the kernel, there is plenty of oprtunity to do something wrong.
This “wrong” is either noticed immediatelly or very very late during the first boot of the new -RT version.


preempt_rt, following mainling, out-of-tree code

Presentation Materials