[ofa-general] Re: [patch 1/9] EMM Notifier: The notifier calls

[Christoph Lameter]

On Wed, 2 Apr 2008, Andrea Arcangeli wrote:

> > Hmmm... Okay that is one solution that would just require a BUG_ON in the 
> > registration methods.
> 
> Perhaps you didn't notice that this solution can't work if you call
> range_begin/end not in the "current" context and try_to_unmap_cluster
> does exactly that for both my patchset and yours. Missing an _end is
> ok, missing a _begin is never ok.

If you look at the patch you will see a requirement of holding a 
writelock on mmap_sem which will keep out get_user_pages().