[FreeVMS] pager question

[Guido]

On Saturday 29 June 2013 12:44:23 BERTRAND Joël wrote:
> 	I agree. For kernel itself, sys_pagefault always returns new
> ressources. For an unprivilegied process, pager has to save a list of
> allocated pages for this process. Pagefault handler only has to return
> new pages when process is loaded in memory, when stack is growing or
> when process uses something like mmap() or brk(). In all other cases,
> pagefault has to raise a new syscall to kill process.

OK, but could you explain why a page fault (essentially a hardware generated 
error condition) and a memory allocation request (software generated, on 
purpose) are handled by the same function (the pagefault handler) when they 
are to be handled differently? Wouldn't it be easier to have separate IPC calls 
and handlers?

> 	No, I don't think. In a first time, I propose that task pager doesn't
> use swapped memory as we need disk I/O drivers to handle swap and as
> these drivers require task pager.

Agreed. My suggestion was more an ultimate goal. At first don't bother with 
swap and disk I/O, physical memory should be more than adequate for now.

Regards,
Guido