Re: client-side memory buffers

[Joshua Stratton]

On Wed, Apr 2, 2008 at 12:25 AM, Neal H. Walfield <neal@walfield.org> wrote:

At Tue, 1 Apr 2008 18:01:25 -0600,

Joshua Stratton wrote:
> On Tue, Apr 1, 2008 at 3:50 PM, Neal H. Walfield <neal@walfield.org> wrote:
>
> > Please don't top post.
> >
> > At Tue, 1 Apr 2008 10:48:02 -0600,
> > Joshua Stratton wrote:
> > >
> > > The problem you described was the client owning the memory object,
> > sending
> > > it to the server, and the server having the ability to unmap the memory
> > > because it has ownership, if I understand correctly.
> >
> > No.  The client has the ability to DoS the server because it manages
> > the memory object.
>
>
> What exactly is the difference between manages and owns?

I was using ownership as a synonym for accounted to, and manage as a
synonym for being able to control (e.g., schedule).  So if the server
is accounted the memory but the client can control the memory, then
the server is susceptible to destructive interference from the client.

> Do you think the client-side
> memory model is worthwhile?  And would the server allocating the memory
> passing it to the client using the Mach semantics allow this client-side
> memory model while avoiding the ability for clients to unmap the
> data?

Yes, I think such accounting is worthwhile, it is what I am doing with
Viengoos, however, I question the ability to realize it using Mach's
interfaces.

 

What's Viengoos?  Is that a new microkernel? 
 

Neal