Re: OOM notifications

Rene Herman
2007-10-18T20:40:54Z

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.