Re: mapping pages into new address spaces

> Hi Josh,
>
>> Here's the only solution I can see: start the new thread executing on
>> a page that I *know* is unmapped, let it page fault on the first
>> instruction, and then map the page on demand.  Is this the right way
>> to do it?  Am I thinking about this in the right way?
>
> Yes, you're right (except that I don't understand why you want a page of
> which you know that it's not mapped, in a newly created address space,
> this should be the case for every (user) page, I think).
> Once the new thread's state is set to active, it waits for a startup IPC
> from its pager. This IPC contains IP and SP for the thread. Upon receiving
> the IPC, the thread will start running at the specified IP and raise a
> page fault. The pager can now reply with the needed page.

Thanks for the replies -- I 'm glad to know I'm thinking about this right.
 My next question would be: why couldn't the kernel automatically accept
any maps/grants that a thread receives from its pager, like it does with
maps/grants that are sent in reply to page faults?  It seems a bit
roundabout that a pager can't proactively map pages into a thread's
address space without cooperation from the thread in question.

It seems logical that the maps sent in response to page faults should
behave like unsolicited maps from a thread's pager.

Josh