Re: OOM notifications

[Rene Herman <rene.herman@keyaccess.nl>]

On 10/18/2007 10:25 PM, Marcelo Tosatti wrote:

> AIX contains the SIGDANGER signal to notify applications to free up some
> unused cached memory:
> 
> http://www.ussg.iu.edu/hypermail/linux/kernel/0007.0/0901.html
> 
> There have been a few discussions on implementing such an idea on Linux,
> but nothing concrete has been achieved.
> 
> On the kernel side Rik suggested two notification points: "about to
> swap" (for desktop scenarios) and "about to OOM" (for embedded-like
> scenarios).
> 
> With that assumption in mind it would be necessary to either have two
> special devices for notification, or somehow indicate both events
> through the same file descriptor.
> 
> Comments are more than welcome.

Given the desktop/embedded distinction you made, do you need both scenarios 
active at the same time? If not, it seems something like a

	echo -n <level> >/proc/sys/vm/danger

could do with just one sigdanger notification point? (with <level> suitably 
defined as or in terms of the used threshold value).

Rene.