Re: Changing from L4 to something else...

[Jonathan S. Shapiro]

On Fri, 2005-10-28 at 14:55 +0200, Yoshinori K. Okuji wrote:

> > If we have resource accountability, we give a user a certain amount of
> > resources, and then we don't care anymore.
> 
> As for the memory, I agree. But some resources are exclusive in nature. For 
> example, if one starts a player with a horrible music on your computer, what 
> do you want to do? One way is to mute the speaker. But, generally speaking, 
> it is nicer to be able to kill it, isn't it?

No. What you want is to cut off access to the sound system. Killing the
process is something that an administrator should not have the right to
do. And frankly, the administrator probably shouldn't have the right to
cut off the sound system either. The *user* definitely *does* need both
options (cut off and kill).

It is true that exclusively allocated resources don't need much in the
way of accounting. The two resources that you really want accountability
for are storage and CPU time.

But I would like something more than just killing the process. I also
want to be able to let the user log out, log back in later, and still
have their music player do something sane. In between, a second user
should be able to log in and use the audio subsystem.

Think of this as sort of like a console switch for audio -- then extend
the idea to the entire pool of exclusive hardware resources that are
associated with the console (sound, microphone, display, keyboard,
mouse, etc). All of these should be part of the login session, and the
session should be reconnectable.


shap