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Date: Sat, 15 Feb 2014 16:37:46 +0200
From: Eli Zaretskii <eliz AT gnu DOT org>
Subject: Re: __dpmi_int() or int86() ?
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> From: "Rod Pemberton" <dont_use_email AT xnohavenotit DOT cnm>
> Date: Sat, 15 Feb 2014 05:03:46 -0500
> 
> But, which is _actually_ faster with CWSDPMI for calling
> RM interrupts?  PMODEDJ?  Is it faster to use __dpmi_int()
> or to use int86()?  Has anyone actually timed this, in the
> past perhaps?  I.e., how does the combined overhead of each
> DJGPP call and DPMI portion compare for both?

I didn't time this, but I don't think the differences matter much.
Any way you do it, there's a need for two mode switches.  A mode
switch eats up thousands of CPU cycles, which is orders of magnitude
more than any overhead incurred by an extra function call.