Re: currency based virtual memory

[Farid Hajji]

> As for Johannes' concerns in a reply to that message, the human mind
> will be available if users can allocate the "currency" among programs
> as they wish. They'll seldomly have to do this as this could be
> automated by programs (by using good default values, for example). For
> example, I seldomly set/change the nice values of processes on my
> GNU/Linux today (unless I'm writing a CD). I've heard users of the old
> Mac OS were able to change some variable of "how much memory
> applications were allowed to use" or something similar, but I don't
> have much knowledge about how that worked in practice.

some processes exhibit a behaviour that you can predict with
somewhat good accuracy. Others are highly dynamic and if you
want to preallocate resources, you'll most likely end up
overallocating (thus wasting resources) or underallocating
(thus falling back to the current behaviour of VM systems).

The user should IMO not bother fiddling with such parameters.
At most, I could imagine that the system collects stats about
different (program, process, user) pairs and use those stats
as a heuristical hint to "probably needed resources in typical
situations". But as stats go, it depends on the stddeviation
and other factors.

Predictive heuristics may help somewhat, but they could also
end up being highly counterproductive (IMHO).

-Farid.

-- 
Farid Hajji -- Unix Systems and Network Admin | Phone: +49-2131-67-555
Broicherdorfstr. 83, D-41564 Kaarst, Germany  | address@hidden
- - - - - - - - - - - - - - - - - - - - - - - + - - - - - - - - - - - -
Due to budget cuts, light at end of tunnel will be out. --Unknown.