Re: [RFC PATCH 2/2] mm: mmu_notifier fix for tlb_end_vma

From: Catalin Marinas
Date: Thu Aug 23 2018 - 08:46:58 EST


On Thu, Aug 23, 2018 at 06:47:09PM +1000, Nicholas Piggin wrote:
> The generic tlb_end_vma does not call invalidate_range mmu notifier,
> and it resets resets the mmu_gather range, which means the notifier
> won't be called on part of the range in case of an unmap that spans
> multiple vmas.
>
> ARM64 seems to be the only arch I could see that has notifiers and
> uses the generic tlb_end_vma. I have not actually tested it.

We only care about notifiers for KVM but I think it only makes use of
mmu_notifier_invalidate_range_(start|end) which are not affected by the
range reset in mmu_gather.

Your patch looks ok from an arm64 perspective (it would be good if Will
has a look as well since he was the last to touch this part for arm64).

--
Catalin