Re: unused swap offset / bad page map.

[Dave Jones <davej@redhat.com>]

On Tue, Aug 27, 2013 at 12:37:18PM +0400, Cyrill Gorcunov wrote:
 > On Mon, Aug 26, 2013 at 06:28:33PM -0400, Dave Jones wrote:
 > >  > 
 > >  > I've not tried matching up bits with Dave's reports, and just going
 > >  > into a meeting now, but this patch looks worth a try: probably Cyrill
 > >  > can improve it meanwhile to what he actually wants there (I'm
 > >  > surprised anything special is needed for just moving a pte).
 > >  > 
 > >  > Hugh
 > >  > 
 > >  > --- 3.11-rc7/mm/mremap.c	2013-07-14 17:10:16.640003652 -0700
 > >  > +++ linux/mm/mremap.c	2013-08-26 14:46:14.460027627 -0700
 > >  > @@ -126,7 +126,7 @@ static void move_ptes(struct vm_area_str
 > >  >  			continue;
 > >  >  		pte = ptep_get_and_clear(mm, old_addr, old_pte);
 > >  >  		pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
 > >  > -		set_pte_at(mm, new_addr, new_pte, pte_mksoft_dirty(pte));
 > >  > +		set_pte_at(mm, new_addr, new_pte, pte);
 > >  >  	}
 > > 
 > > I'll give this a shot once I'm done with the bisect.
 > 
 > I managed to trigger the issue as well. The patch below fixes it.
 > Dave, could you please give it a shot once time permit?

Seems to do the trick.

Tested-by: Dave Jones <davej@fedoraproject.org>

	Dave