Subject: Re: Interrupt, interrupt threads, continuations, and kernel lwps
To: Andrew Doran <ad@netbsd.org>
From: Jason Thorpe <thorpej@shagadelic.org>
List: tech-kern
Date: 02/21/2007 10:05:00
On Feb 21, 2007, at 2:09 AM, Andrew Doran wrote:

> Conversely, the changes I have to handle
> interrupts using LWPs add 29 instructions to a typical interrupt  
> chain on
> x86, to swap stack and curlwp. It works, and it's a solution that  
> can just
> be "dropped in".

The problem is I don't think it CAN be "dropped in" on a platform like  
VAX, m68k, or SPARC.  It's easy on x86 because of how simple its  
interrupt model is.  But I don't think that's true on platforms that  
have processor-defined interrupt levels and auto-vectored interrupts.

-- thorpej