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From: trl@cbrma.UUCP (Tom Lanning)
Newsgroups: net.lang.c++
Subject: C++ and demand paging, i.e. locality
Message-ID: <4668@cbrma.UUCP>
Date: Tue, 24-Jun-86 12:51:19 EDT
Article-I.D.: cbrma.4668
Posted: Tue Jun 24 12:51:19 1986
Date-Received: Sat, 28-Jun-86 05:56:38 EDT
Organization: AT&T-BL, RMAS, Columbus
Lines: 18
Keywords: locality paging


	I am new at tuning software for a demand paging operating
system, but it seems that heavy use of derived classes with virtual
functions could really cause a decrease in locality of reference
if each class is implemented in a single source file.  Since a
function of derived class "C" calls functions implemented in class
"B", (which uses some functions implemented in class "A"), any hope
of keeping heavily used routines together in the same page would
result in wacky source arrangments.  If "true" hidding of implementation
is done then nothing can really be done to group the functions so
paging is minimized.

	Does anyone have any input on this subject?  Are there things
that I can do with/without C++ that would aid performance on a paging
OS?  Any comments or suggestions are invited.
-- 

  Tom Lanning   AT&T Bell Laboratories   Columbus OH   43213     614-860-4153