Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!icdoc!qmw-cs!rabin From: rabin@cs.qmw.ac.uk (Rabin Ezra) Newsgroups: comp.sys.acorn Subject: Re: Program for virtual memory? Keywords: virtual memory Message-ID: <3303@sequent.cs.qmw.ac.uk> Date: 4 Feb 91 14:30:18 GMT References: <1682@abekrd.UUCP> Organization: Computer Science Dept, QMW, University of London, UK. Lines: 22 Summary: Expires: Sender: Followup-To: Distribution: It strikes me this shoudn't be too hard. Major problems include IRQ service etc, but if you only page the application area, and have your IRQ's in modules, it would be ok. I thought you might hack the task launch stuff, so that if an application flagged itself as pagable, the task managment stuff would provide vm. Remember though that vm performance on an ARM is poor due to the massive page size, so you would need to group often called code together, with less used code in other pages. This can't be done easily. Also note that the BSD trick of paging code from binaries won't work either, as most code tends to be delivered squeezed, so you can't trivially tell where the page you need is. (I gather that RISCiX squeezes swapped stuff though) Rabin Ezra -- Rabin Ezra UUCP: rabin@qmw-cs.UUCP PhD Student, JANET: rabin@uk.ac.qmw.cs Dept of Computer Science, Internet: rabin@cs.qmw.ac.uk Queen Mary and Westfield College, London E1 4NS. If you have problems try qmc in place of qmw. U.K.