page-up problem/question

[John Cornelius]

The 2 extremes of the problem you articulate are:
	1)	bring in the initial startup page and page fault everything
		else in

	2)	bring the entire text into memory (if possible) and allow pages
		to be replaced arbitrarily by the demand paged system as other
		requirements for the space occur.

In the first case you get an arbitrary collection of pages scattered throughout
memory and every time there's a page fault you pay with the time required to
service it. In the second case you pay on the front end by bringing in
everything at once and then you pay again as small chunks (pages) get
deallocated by the requirements of others. 

It's funny how some things never change. We still, after 30 years in this
business, have to trade off speed, money, and memory. 

The whole discussion becomes moot if one has adequate memory for all
requirements but that only encourages more (Parkinsonian) requirements for the
available resources. One has to start with whatever is a given, use whatever
gimmicks one has to overcome the starting limitations, and then go ahead and
have a homebrew because there isn't any best solution.

John Cornelius
Western Scientific