Re: Out of memory kernel deat

Sam Mortimer (
Mon, 12 May 1997 16:16:25 +0100 (BST)

On Mon, 12 May 1997, Thomas Koenig wrote:
> I'd propose a fairly simple solution: send a SIGURG signal to
> whatever process has a signal handler for it installed.
> This process could then do whatever it wants to, such as allocating
> more swap, killing off an errant process or send an E-Mail to
> the admin to go out and buy more RAM.
> Policy is for userland.

By far the best proposal I've seen so far.

We've seen many different example methods of how to choose which processes
to kill. Moving the algorithm out of the kernel and into a userland
daemon would provide a means by which each and every one of these methods
could be implemented.

We could implement this simply by extending the capabilities of kerneld.
Naturally, kerneld (or a separate kerneld thread), would have to take
special precautions to make sure it is always runnable and also give
itself a higher priority.