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Re: [f-cpu] More on Interrupts

On Fri, Jan 18, 2002 at 08:28:50AM -0700, Ben Franchuk wrote:
> richard hartny wrote:
> Nowdays 32 interrupt vectors should be standard.

For 32-bit CPUs, yes.

> Also since most modern OS do a task swap after
> a interrupt a fast way of of setting task priorities
> and getting the next sorted task would be useful.

Since interrupts tend to arrive frequently, interrupt service routines
should return to the interrupted task as soon as possible. A task
switch, on the other hand, is rather expensive -- a lot of state has
to be saved and reloaded, even with SRB.

Most interrupts deal with I/O - they indicate that data has arrived or
can be sent, or that some device has changed its state. Usually, none
of these events triggers an automatic task switch.

 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
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