POS

Fare Rideau rideau@ens.fr
Tue, 13 May 1997 11:19:28 +0200 (MET DST)


>: Chris Bitmead

> Everybody on this list seems to want 1 address space. I can't see how
> you will know how much your http server is taking up without killing
> it, doing a gc and finding out.
>
As I already explained,
(1 physical address space) != (1 logical address space)

Here is what I've just added to my page:
http://www.eleves.ens.fr:8080/home/rideau/Tunes/LLL/storage.html

<DT>Resource tracking and quotas
<DD>
<UL>
<LI>No need to have multiple <em>physical</em> address spaces
	to achieve multiple <em>logical</em> address spaces.
	To achieve quotas in resource usage,
	you just need keep track of how much resources are used
	by the current resource user(s).
<LI>An efficient implementation would:
	<UL>
	<LI>keep track of usage synchronously for seldom used resources;
	<LI>just update global counters at user-switch time
		for resources that are constantly evolving
	<LI>When there are recursive users,
		either they might all be updated at user-switch time,
		or only the deepest users are, and the counters for the
		others are (implicitly or explicitly) invalidated.
<LI>All this can be done by reflectively modifying the GC/threading code,
	without any special OS support besides generic reflection.
</UL>

Regards,

== Fare' -- rideau@ens.fr -- Franc,ois-Rene' Rideau -- DDa(.ng-Vu~ Ba^n ==
Join the TUNES project for a computing system based on computing freedom !
                TUNES is a Useful, Not Expedient System
URL: "http://www.eleves.ens.fr:8080/home/rideau/Tunes/"