> On Thu, 18 Oct 2007 22:38:21 +0200
> Rene Herman <rene.herman@keyaccess.nl> wrote:
>
>> 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).
>
> If you do that, how are applications to know which of the two
> scenarios is happening when they get a signal?