Re: mlockall and mmap of IO devices don't mix

Andi Kleen
2003-10-04T07:03:11Z

Joe Korty <joe.korty@ccur.com> writes:

>
> I do not believe that the above constitutes a correct fix. The
> problem is that follow_pages() is fundamentally not able to handle a
> mapping which does not have a 'struct page' backing it up, and a
> mapping to IO memory by definition has no 'struct page' structure to
> back it up.

The 2.4 vm scanner handles this by always checking VALID_PAGE().

Maybe follow_pages() should do that too?

-Andi