Xref:	news2.mv.net comp.os.msdos.djgpp:6091
From:	Charles Sandmann <sandmann AT clio DOT rice DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Interrupt overhead with DJGPP's extender
Date:	Wed, 17 Jul 1996 15:08:38 CDT
Organization:	Rice University, Houston, Texas
Lines:	13
Message-ID:	<31ed4846.sandmann@clio.rice.edu>
References:	<31EC2DD4 DOT 7A94 AT ee DOT ubc DOT ca>
Reply-To:	sandmann AT clio DOT rice DOT edu
NNTP-Posting-Host:	clio.rice.edu
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> In particular, I'd like to know what overhead is imposed by DJGPP's DOS 
> extender for interrupt handling (in GNAT Ada - although I can't see why 

The interrupt handling overhead is a function of the DPMI provider you are
using, so there isn't any single answer here.  The overhead is also 
dependent on if a hardware interrupt happens while you are in protected
mode, or real mode, and if you have hooked the interrupt (in either mode).

The fastest case would be using either CWSDPR0 or PMODE/DJ - both of which
are ring 0 providers which don't swap interrupt stacks - and to have all
interrupts handled in the mode which they happen (no mode swaps).  In
this case there is no additional overhead vs the standard "real mode"
type interrupt handlers.

- Raw text -