Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/17/84; site opus.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!hao!cires!nbires!opus!rcd From: rcd@opus.UUCP (Dick Dunn) Newsgroups: net.arch,net.unix-wizards Subject: page-up problem/question Message-ID: <895@opus.UUCP> Date: Fri, 12-Oct-84 04:40:47 EDT Article-I.D.: opus.895 Posted: Fri Oct 12 04:40:47 1984 Date-Received: Sat, 13-Oct-84 06:41:49 EDT Distribution: net Organization: NBI,Inc, Boulder CO Lines: 22 By "page-up", I mean the process of getting the initial chunk of pages loaded for a program to do useful work in a demand-paged system. If you have any good direct info on this, I'd like to see it and it might be of sufficient general interest to post it. If you have references, please mail them to me and I'll try to chase them and summarize. A little more on the nature of the problem: When starting a program which is demand-paged, the obvious (but naive) approach is to load the page containing the starting address and begin execution. From there, it will page-fault itself up to a reasonable set of useful pages. However, the page up happens in a somewhat haphazard fashion, particularly with programs which have large collections of utility routines. It's somewhat as if the program were being swapped in in near-entirety, except that the pages are being loaded in a rather random pattern. This can be waved away in a big system with fast disks, many users, and a fair number of commonly-used programs with shared code space. However, it hurts a lot on a small, single-user system with a slow disk. Obviously, if the program is below a certain size threshold it's better to swap in the whole thing and save the disk seek time. Other than this--Any thoughts? -- Dick Dunn {hao,ucbvax,allegra}!nbires!rcd (303)444-5710 x3086 ...Relax...don't worry...have a homebrew.