[PATCH 00/13] mmu_notifier kill invalidate_page callback

[Jerome Glisse]

On Thu, Aug 31, 2017 at 07:19:19PM -0400, Felix Kuehling wrote:
> On 2017-08-31 03:00 PM, Jerome Glisse wrote:
> > I was not saying you should not use mmu_notifier. For achieving B you need
> > mmu_notifier. Note that if you do like ODP/KVM then you do not need to
> > pin page.
> I would like that. I've thought about it before. The one problem I
> couldn't figure out is, where to set the accessed and dirty bits for the
> pages. Now we do it when we unpin. If we don't pin the pages in the
> first place, we don't have a good place for this.
> 
> Our hardware doesn't give us notifications or accessed/dirty bits, so we
> have to assume the worst case that the pages are continuously
> accessed/dirty.
> 
> I'd appreciate any advice how to handle that. (Sorry, I realize this is
> going a bit off topic.) A pointer to a document or source code would be
> great. :)

In invalidate_range_start() ie same place as where you unpin but instead
of unpining you would just call set_page_dirty()

Jérôme