Hi,

Why is Linux kernel considered a (hard) realtime OS? I already

Linux kernel is never considered a real time OS.
A real time OS should be predictable.The general linux kernel is not predictable because of many reasons. A few are it uses virtual memory. when there is virtual memory there will be page swaps which are un predictable.
And the linux scheduler is not a deterministic one.
There is a scheduler project which provides a deternistic behaviour to the scheduler.This scheduler is called O(1) scheduler. This gives a constant scheduling latency. This is used in many embedded linux to make it a real time OS. Ex: motavista

understand the basic reason is that the linux kernel does not
guarantee that a task will be completed on time. But I would
appreciate answers in terms of more of kernel jargons.

What stops us from classifying kernel as hard RTOS? Is it because at

An RTOS is just a facilitator to build Real time systems. A Real time system developer should analyse a RTOS wether is will be useful for his system. If some body is holding spin lock and making it non-preemptive its a bad design. So even a RTOS linux has spin locks. Its the designer who should take care.

times the kernel is non-preemptive (for e.g. while holding spinlocks)?
Has it got something to do with interrupt latency / scheduling latency
etc?

Is the behaviour of the kernel (when it is preemptive) similar to hard
real time OS ??

Thanks,

Rick
-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs

Reply via email to