when to mark reserved low memory pages

[John Rose]

On Fri, 2004-09-24 at 21:15, Benjamin Herrenschmidt wrote:
> Why ? because they get freed when you mmap them and later quit the
> userland process ? In this case, the option of marking them reserved
> might lead to an ever increasing page count (or not), make very sure
> of that, as get_page() will increase count but free_page() will not
> decrease it for a reserved page.

Ok retry :)  If you were in a hypothetical situation where page count
wasn't the issue, and you specifically needed the pages marked reserved,
where would you do it?

And how to handle the discontig case?

Thanks-
John