Re: [RFC PATCH] mm/rmap: do not call mmu_notifier_invalidate_page() v3

[Jerome Glisse]

On Tue, Aug 29, 2017 at 12:09:45PM -0700, Linus Torvalds wrote:
> On Tue, Aug 29, 2017 at 12:05 PM, Jérôme Glisse <jglisse@xxxxxxxxxx> wrote:
> > Some MMU notifier need to be able to sleep during callback. This was
> > broken by c7ab0d2fdc84 ("mm: convert try_to_unmap_one() to use
> > page_vma_mapped_walk()").
> 
> No. No no no.
> 
> Didn't you learn *anything* from the bug?
> 
> You cannot replace "mmu_notifier_invalidate_page()" with
> "mmu_notifier_invalidate_range()".
> 
> KVM implements mmu_notifier_invalidate_page().
> 
> IT DOES NOT IMPLEMENT THAT RANGE CRAP AT ALL.
> 
> So any approach like this is fundamentally garbage. Really. Stop
> sending crap. This is exactly tehe same thing that we already reverted
> because it was broken shit. Why do you re-send it without actually
> fixing the fundamental problems that were pointed out?
> 

Sorry i missed the kvm not implementing the range() only callback so
i am gonna respin with start/end.

Jérôme