Subject: Re: userid partitioned swap spaces.
To: None <tech-kern@netbsd.org>
From: Guenther Grau <Guenther.Grau@bk.bosch.de>
List: tech-kern
Date: 12/15/1998 13:23:16
Hi,

Ignatios Souvatzis wrote:
> 
> On Tue, Dec 15, 1998 at 01:13:12PM +0200, Jukka Marin wrote:
> > I know there isn't a simple a perfect solution to this, but I would rather
> > have a Netscape process killed by the system than have the whole server die
> > or lock up.  I guess this isn't much of a problem on a single-user machine
> > with 256 MB of RAM and 4 GB of swap.. but it seems to be a problem on a
> > smallish single-user system already, not to mention public shell systems.
> 
> The problem is when the shortage happens, you simply don't know who the "right"
> culprit to kill is.
> 
> Netscape might get N-20 pages of swap, then, say, some small cron job might
> need 25. It might be possible to implement to kill the last process needing
> swap, but this wouldn't be necessarily right.

Maybe we need a priority level assigned to processes which indicates to 
the kernel which processes should be killed first in situations with
otherwise unresolvable memory shortage. System processes would have
higher priorities, users could choose from a lower range. This makes
it still not easy to treat all users/users processes equal, but it
would at least offer the user a chance to say, hey, if I run out of
memory, my netscape is too big a memory hog, so rather kill it than my
X Server.

What about it?

  Guenther