Re: User space out of memory approach

From: Bodo Eggert <7eggert@gmx.de>
To: Edjard Souza Mota <edjard@gmail.com>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Ilias Biris <xyz.biris@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: User space out of memory approach
Date: Sun, 16 Jan 2005 17:28:26 +0100	[thread overview]
Message-ID: <E1CqDGM-0000wi-00@be1.7eggert.dyndns.org> (raw)
In-Reply-To: fa.ht4gei4.1g5odia@ifi.uio.no

Edjard Souza Mota wrote:

> What do you think about the point we are trying to make, i.e., moving the
> ranking of PIDs to be killed to user space?

If my system needs the OOM killer, it's usurally unresponsive to most
userspace applications. A normal daemon would be swapped out before the
runaway dhcpd grows larger than the web cache. It would have to be a mlocked
RT task started from early userspace. It would be difficult to set up (unless
you upgrade your distro), and almost nobody will feel like tweaking it to
take the benefit (OOM == -ECANNOTHAPPEN).

What about creating a linked list of (stackable) algorhithms which can be
extended by loading modules and resorted using {proc,sys}fs? It will avoid
the extra process, the extra CPU time (and task switches) to frequently
update the list and I think it will decrease the typical amount of used
memory, too.