Re: [patch 4/6] mm: merge populate and nopage into fault (fixes nonlinear)

Nick Piggin
2007-03-07T10:04:36Z

On Wed, Mar 07, 2007 at 10:45:03AM +0100, Nick Piggin wrote:
> On Wed, Mar 07, 2007 at 10:32:22AM +0100, Peter Zijlstra wrote:
> >
> > Can recollect as much, I modelled it after page_referenced() and can't
> > find any VM_NONLINEAR specific code in there either.
> >
> > Will have a hard look, but if its broken, then page_referenced if
> > equally broken it seems, which would make page reclaim funny in the
> > light of nonlinear mappings.
>
> page_referenced is just an heuristic, and it ignores nonlinear mappings
> and the page which will get filtered down to try_to_unmap.
>
> Page reclaim is already "funny" for nonlinear mappings, page_referenced
> is the least of its worries ;) It works, though.

Or, to be more helpful, unmap_mapping_range is what it should be
modelled on.