Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!think.com!samsung!usc!elroy.jpl.nasa.gov!ncar!gatech!ncsuvx!news From: cocoiii@hobbes.ncsu.edu (John Vestal) Newsgroups: comp.sys.amiga.misc Subject: Re: How do we change the scheduler? (Was Re: Multitasking at home...) Message-ID: <1991Jan14.200405.19816@ncsuvx.ncsu.edu> Date: 14 Jan 91 20:04:05 GMT References: <17210@cbmvax.commodore. <7504@sugar.hackercorp.com> <42459@ut-emx.uucp> <7511@sugar.hackercorp.com> Sender: news@ncsuvx.ncsu.edu (USENET News System) Reply-To: cocoiii@hobbes.ncsu.edu (John Vestal) Organization: NCSU Computing Center Lines: 33 I've been watching this very interesting discussion about multitasking, and would like to make a few comments. I don't know about how the kernals in MAC OS, AmigaDOS, OS/2, UNIX, or OS-9 work, but I've used them all but OS/2. The Mac does a decent job of 'kludging multitasking'. You can't (or I haven't found a way) of changing tasks priority's on the Mac though. AmigaDOS does multitasking very smoothly, but I have seen (mainly games) that will not let anything else run. Well, at least not get too them, I don't know that they aren't running, but to me they're not there. If you change a very CPU intensive task to a higher priority, other tasks can 'stop'. On UNIX you can run a lot of programs and you can never 'stop' a process, without killing it, or setting it's priority as low as possible. The difference between the two, if I have a compile that (for fun) takes all of the CPU, and a shell running. The compile is one above the shell. On AmigaDOS, the shell gets no time, until the compile is done. On UNIX, the shell gets a certain percentage less then the compile. It still gets some though. This is also how OS-9 works. Tasks age, and after they are so old, according to the priority, they get a CPU cycle. They also get any 'leftover' CPU, but AmigaDOS does this too. Now, for me as a user, I want any process that I am running to get some time. I should tell it at least how often I want it to run. It can run more often, but at least this often. OS-9 does this, and it doen't give up 'real-time response'. As a matter for fact, it the OS of choice for realtime work. At least from what I've seen and heard. Anyway that's my 2 cents worth. cocoiii (John Vestal) -- ****************************************************************************** * cocoiii@catt.ncsu.edu Phone: (919) 831-2890 North Carolina State * * John Vestal P.O. Box 21537 Raleigh, NC 27607 University * ******************************************************************************