I wrote: > There is also Ingo Molnar's (and probably others') RT-PREEMPT patches > currenty under development. These really do try to get nearly every > point preemtible. Drivers should synchronise with semaphores, mutexes > (which both do priority inheritance), and completions. I think that's a bit wrong. It doesn't make sense for a semaphore to do priority inheritance as the whole point of a semaphore is that things are supposed to receive notification when something has finished, and the thing that does the notifying does not try to make progress for the waiters. While a mutex identifies a critical section and the process/thread holding the mutex moves out of the way quickly when a high priority thread/process is waiting (essentially starts making rapid progress for the benefit of the waiter, since the waiter has important things to do). -- Tristan Wibberley Opinions expressed are my own and do not necessarily coincide with those of my employer, etc. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
