Path: utzoo!yunexus!geac!daveb
From: daveb@geac.UUCP (David Collier-Brown)
Newsgroups: comp.arch
Subject: Re: Random thoughts on paging.
Summary: Sidebar on stereotyped initial page-faults.
Message-ID: <2789@geac.UUCP>
Date: 30 May 88 13:30:02 GMT
Article-I.D.: geac.2789
Posted: Mon May 30 09:30:02 1988
References: <338@piring.cwi.nl> <413@m3.mfci.UUCP>
Reply-To: daveb@geac.UUCP (David Collier-Brown)
Organization: The Geac "I Think the Computer Should Do that" Department
Lines: 28


In article <338@piring.cwi.nl> jack@cwi.nl (Jack Jansen) writes:
=I have the feeling that a lot of programs will go through a fixed
=sequence of page faults during startup. This is especially true of
=programs like editors, that will always read your startup script and
=execute numerous commands before finally entering interactive mode.
=
=Now, it seems it would be worthwhile to build a list of the first,
=say, 50 pages in the order of need, and attach that to the program so
=that the OS can immedeately start paging in the next page...

A side point: one should do such with at least a semi-automatic facility,
like a profiler.  A facility to automatically collect page-fault lists for a
particular program and turn them into preload lists at a later date
would be useful, and conceptually straightforward:

 for the first N executions:
	collect the first 100 page faults
 for the N+1th execution
	find the longest common subsequence
	make that the preload list.

--dave
-- 
 David Collier-Brown.  {mnetor yunexus utgpu}!geac!daveb
 Geac Computers Ltd.,  | "His Majesty made you a major 
 350 Steelcase Road,   |  because he believed you would 
 Markham, Ontario.     |  know when not to obey his orders"