[ros-kernel] mdl patch

[Vizzini]

On Thu, 2004-06-17 at 11:40, Hartmut Birr wrote:

First off, I guess I hadn't actually typed 'make' before I sent this
patch in.  I've eliminated a lot of stuff, so what's left is very basic
return val checking.  My bad for not testing this better before I posted
it for review...

> there was some changes within the mdl implementation:    
> - The caller is responsible for freeing a mdl for a paging io request.
>   This made it possible to allocate the mdl for a short number of pages
>   from the stack. This is used to read/write from swap file and to
>   read/write of cache segments.   

Yeah, I found that when I couldn't get the patched OS to compile.

> - MmWriteToSwapPage and MmReadFromSwapPage has changed. The caller does 
>   only pass the physical page to this functions. This functions are 
>   responsible for allocating the mdl. It is used the feature from above.

Ditto.  I think the changes were a good idea, for what it's worth.

 -Vizzini