Re: [patch 7/7] powerpc: lockless get_user_pages_fast

[Nick Piggin <npiggin@suse.de>]

On Tue, Jun 10, 2008 at 12:00:48PM -0700, Christoph Lameter wrote:
> On Thu, 5 Jun 2008, npiggin@suse.de wrote:
> 
> > Index: linux-2.6/include/linux/mm.h
> > ===================================================================
> > --- linux-2.6.orig/include/linux/mm.h
> > +++ linux-2.6/include/linux/mm.h
> > @@ -244,7 +244,7 @@ static inline int put_page_testzero(stru
> >   */
> >  static inline int get_page_unless_zero(struct page *page)
> >  {
> > -	VM_BUG_ON(PageTail(page));
> > +	VM_BUG_ON(PageCompound(page));
> >  	return atomic_inc_not_zero(&page->_count);
> >  }
> 
> This is reversing the modification to make get_page_unless_zero() usable 
> with compound page heads. Will break the slab defrag patchset.

Is the slab defrag patchset in -mm? Because you ignored my comment about
this change that assertions should not be weakened until required by the
actual patchset. I wanted to have these assertions be as strong as
possible for the lockless pagecache patchset.