Subject: Re: Driver and thread model
To: Manuel Bouyer <>
From: Thorbj=F6rn_Jemander <>
List: tech-kern
Date: 09/12/2000 07:28:29
Hello again, Manuel:

>> 1. How does NetBSD schedule threads with different
>> priorities? Is there any (soft) 'real-time level' as in
>> e.g. BeOS? If not, is there some legal way for a thread
>> to run uniterrupted for a 'longer' period of time (i.e. longer
>> than the scheduler time quanta)?
>You mean, in kernel or userland ?


>The kernel isn't preemptive yet, so

Sureley the scheduler preempts the processes (is that the term
used in NetBSD?) in userland? Do you mean that processes in
the kernel run uninterrupted? Does that go for modules loaded
into the kernel, too?

>once you're in kernel you run until you return from syscall or you call
>tlseep(), or a highter priority interrupt occurs.

Where can I find out more about the kernel internals (without figuring
it out from the source), any papers or books covering the subject?
I think I saw that NetBSD implements POSIX-threads somewhere,
I wonder how they are implemented: as mapped to some sort of
'native' threads or adopted and implementeted as /the/ thread

Thorbj=F6rn Jemander