[$] The hierarchical constant bandwidth server scheduler

The POSIX
realtime model, which is implemented in the Linux kernel, can ensure
that a realtime process obtains the CPU time it needs to get its job done.
It can be less effective, though, when there are multiple realtime
processes competing for the available CPU resources. The hierarchical
constant bandwidth server patch series, posted by Yuri Andriaccio with
work by Luca Abeni, Alessio Balsini, and Andrea Parri, is a modification to
the Linux scheduler intended to make it possible to configure systems with
multiple realtime tasks in a deterministic and correct manner.