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Mail Archives: djgpp/1997/07/13/05:44:29

Message-ID: <33C8A01A.E8E@mcs.nl>
Date: Sun, 13 Jul 1997 11:30:03 +0200
From: Peter Zijlstra <peter AT mcs DOT nl>
Reply-To: home AT somewhere DOT world DOT mcs DOT nl
Organization: Zembla
MIME-Version: 1.0
To: DJGPP mailing list <djgpp AT delorie DOT com>
Subject: Q: interrupts and segment changes.

Hi y'all,

I was reading through some interrrupt sample code and noticed that
almost everybody changed at least 1 segment register, some for custom
stacks, other for custom ds, es, fs and gs's. My question is why is this
done ? All my int. handlers in Watcom used the default stack and default
ds, es etc.. and I do want to avoid switching segment registers because
I write for a Pentium Pro.

Another question which popped into mind is, why is it nessecairy to lock
your int. handler data + code. Any desent vitrual memory manager
wouldn't dare touching memory that is as often used as those are not
even in memory tight situations, or am I wrong here ?

Hope someone has something usefull to say about all this :)

greetinx,

-----------------------------------
Peter Zijlstra
aka. The Mage / ZeMBLA - Main Coder
E-Mail: peter at mcs dot nl
-----------------------------------

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