Re: [PATCH mm-unstable v2 00/10] mm/kvm: locklessly clear the accessed bit

Paolo Bonzini
2023-06-09T09:18:25Z

On 5/27/23 01:44, Yu Zhao wrote:
> TLDR
> ====
> This patchset adds a fast path to clear the accessed bit without
> taking kvm->mmu_lock. It can significantly improve the performance of
> guests when the host is under heavy memory pressure.
>
> ChromeOS has been using a similar approach [1] since mid 2021 and it
> was proven successful on tens of millions devices.
>
> This v2 addressed previous requests [2] on refactoring code, removing
> inaccurate/redundant texts, etc.
>
> [1]https://crrev.com/c/2987928
> [2]https://lore.kernel.org/r/20230217041230.2417228-1-yuzhao@google.com/

From the KVM point of view the patches look good (though I wouldn't
mind if Nicholas took a look at the ppc part). Jason's comment on the
MMU notifier side are promising as well. Can you send v3 with Oliver's
comments addressed?

Thanks,

Paolo