Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!mimsy!jds
From: jds@mimsy.UUCP (James da Silva)
Newsgroups: comp.os.minix
Subject: Swapping (was Re: Blitter with fork)
Message-ID: <17198@mimsy.UUCP>
Date: 30 Apr 89 16:54:12 GMT
References: <1162@uvm-gen.UUCP> <2972@sun.soe.clarkson.edu>
Reply-To: jds@mimsy.umd.edu (James da Silva)
Organization: University of Maryland Computer Science Department
Lines: 38

In article <2972@sun.soe.clarkson.edu> jk0@sun.soe.clarkson.edu
(Jason Coughlin) writes:
>From article <1162@uvm-gen.UUCP>, by ackerman@kira.uvm.edu (Steve Ackerman):
>> My friend and I have been working on a swapper for Minix 1.3 PC.
>
>	My understanding of the situation is that swapping doesn't have
>anything to do with process SIZE on the PC (probably different on the
>ST).  It will only allow you to run MORE processes.  VM anyone?
>

>	Personally, I wouldn't want to run more processes in Minix. ...
[because it gets SLOW]

It's true that swapping won't allow bigger processes in PC Minix.  It's
also true that Minix performs badly with N processes running, N > 2, due
(in my opinion) mostly to the fact that FS is single-tasking.  This could
be fixed, by the way.

But, swapping to a hard disk would still be a big win.  Consider the common
(at least for me) case where you want to run a make in the background and
do some editing and poking around in the foreground.  You have to be very
careful now because if you use up too much memory in the foreground, the
make will die a horrible death.  Ooops.  The same thing happens if you
actually want to hang a terminal on one of your tty ports and log in that
way.  Uucp anyone?  Cron?  Degraded performance in these cases is
infinitely preferable to dying processes.

To Steve Ackerman: I'm sure I speak for many others when I say please
please oh please post your swapper!  Even if you run out of free time and
can't finish it or you win the Pennsylvania lottery and move to Rio, post
what you have!  Nations will sing your praise!

Ahem, ok.  I've regained my composure.  Minix needs a swapper.

Jaime
...........................................................................
: domain: jds@mimsy.umd.edu				     James da Silva
: path:   uunet!mimsy!jds