:In this context, what is a task? Something similar to a kernel thread? :If there are N (user-level POSIX) threads in an application, how many :tasks are there?

N. A task is simply an execution context for the scheduler. That's it, nothing special. The scheduler need only know about tasks and doesn't really have to know about meta-data such as (except for the MMU context) data stored in Processes, nor does it really need to know what *kind* of task it is messing with.

Simplicity is the best solution.

:> complicates the code. We can trivially use the existing priority :> scheme to schedule interrupt tasks (threads). : :The kernel doesn't know at what priority the threads run, so how can :it effectively schedule them? : :Dan Eischen

If you have one Task == one Thread, the priority is in the Task structure, so the kernel would know. Obviously the scheduler must know or it can't properly schedule the execution context.