4.4.1. Can Linux handle real-time requirements?

• Linux is multiuser, timesharing system

• Kernels up until 2.4 are not preemptible (2.5 started to integrate low latency and kernel preemption patches)

• Alternatives are
  1. Enhance linux kernel performance (Timesys patch + proprietary modules)
  2. Introduce new lower, real-time level
     • RT-Linux (Victor Yodaiken FSM Labs) is patented . Not clear if patent would stand up in court.
     • RTAI (Paolo Montegazza) is GPLd

• Two-level structure is faster but more complicated