Xref:	news2.mv.net comp.os.msdos.djgpp:2323
From:	lmm <lrms AT vortex DOT ufrgs DOT br>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Locking Memory?...
Date:	1 Apr 1996 17:04:10 GMT
Organization:	Laboratorio de Medicoes Mecanicas
Lines:	12
Message-ID:	<4jp2aa$o2@prelo.ufrgs.br>
References:	<4isq3j$s73 AT news DOT csus DOT edu>
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To:	rpope AT saclink1 DOT csus DOT edu
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

   Locking memory is used to make a memory block not pagenable, that is,
it will not be swapped to disk. This is done because in real-time
aplications (using hardware interrupts, etc) the data and code must
residy in RAM. If the data was swapped to disk when the interrupts occur
the process of reading that page again would  require to much time.
   I don't understand much of 386 protect-mode descriptor's but i guess
that function just toggles some bit in the descriptor to tell the 
processor that the block is not paginable. If you read the dpmi specs,
you can find a better explanation about that. 

Luciano R. M. Silva

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