Re: some other memory considerations.

[Marcus Brinkmann]

At Wed, 27 Oct 2004 00:27:13 +0200,
Bas Wijnen <address@hidden> wrote:
> 
> [1  <text/plain; ISO-8859-1 (7bit)>]
> Marcus Brinkmann wrote:
> > At Tue, 26 Oct 2004 12:13:56 -0400,
> > Rian Hunter <address@hidden> wrote:
> > 
> >>I'm assuming that the pagers are notified (either by the kernel 
> >>or in some user protocol) whenever maps are granted to its client, or 
> >>something like that.
> > 
> > 
> > No.  If you need to manage the mapping in any way, then it is entirely
> > up to you.  Ie, your RPC stub generator could register the mapping, if
> > there is any use (ie, if it can be reestablished in case it goes
> > away).  There is no L4-way to inspect the page tables of a task or to
> > get notified of changes.
> 
> I don't think this answers the question.
> There is no need for a notification of a mapping, because it doesn't 
> happen unexpectedly.  You can only receive mappings (or grants) via an 
> IPC operation.  So you must be prepared to receive IPC from the task 
> which maps the memory to you (in case of the Hurd, physmem), and you 
> must have set the "I am prepared to receive mappings"-flag.  So you 
> never get a mapping without knowing it.

Oh yes, good point.  In fact, you can limit mappings and grants to a
specific receive window, which location and size you can set.

Thanks,
Marcus