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Article #2922Re: paging and loading
From: Jim Giles
Date: Thu, 25 Sep 1986 18:08
Date: Thu, 25 Sep 1986 18:08
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In article <389@cci632.UUCP> rb@ccird1.UUCP (Rex Ballard) writes: >Most applications spend 90% of their time executing only 10% of their >code. Interactive and transaction processing applications spend >nearly 95% of their time in a "wait for I/O, parse, loop" with an >occaisional "do special purpose 'case' processing". There are more >than a few stories of such applications where swapping that involved >a loop smaller than 2K caused serious degradation due to the 64K to >1Mb "tails" that would get swapped in with them. > I've seen codes that spend 99% of their time in just 1-2% of the code. So what? The code only occupies 2% of the memory image of the program. The rest of the memory image is data, and 90% of it is being processed repeatedly by that tight loop in the code. Yes, when you job mix is composed mainly of small and/or interactive processes, by all means you should have a VM system. I question the need for VM in contexts where this is not true. J. Giles Los Alamos
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!cmcl2!lanl!jlg From: jlg@lanl.ARPA (Jim Giles) Newsgroups: net.arch Subject: Re: paging and loading Message-ID: <7963@lanl.ARPA> Date: Thu, 25-Sep-86 14:08:03 EDT Article-I.D.: lanl.7963 Posted: Thu Sep 25 14:08:03 1986 Date-Received: Fri, 26-Sep-86 00:57:13 EDT References: <832@hou2b.UUCP> <389@cci632.UUCP> Reply-To: jlg@a.UUCP (Jim Giles) Organization: Los Alamos National Laboratory Lines: 20