On Sat May 27, 2023 at 9:44 AM AEST, Yu Zhao wrote:
> Add mmu_notifier_ops->test_clear_young() to supersede test_young()
> and clear_young().
>
> test_clear_young() has a fast path, which if supported, allows its
> callers to safely clear the accessed bit without taking
> kvm->mmu_lock.
>
> The
On Fri, May 26, 2023, Yu Zhao wrote:
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 0e571e973bc2..374262545f96 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -258,6 +258,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
> #ifdef
On 5/31/23 21:17, Jason Gunthorpe wrote:
+ int (*test_clear_young)(struct mmu_notifier *mn, struct mm_struct *mm,
+ unsigned long start, unsigned long end,
+ bool clear, unsigned long *bitmap);
+
Why leave clear_young behind?
On Tue, Jun 6, 2023 at 2:34 AM Tzung-Bi Shih wrote:
>
> On Fri, May 26, 2023 at 05:44:26PM -0600, Yu Zhao wrote:
> > +/*
> > + * Architectures that implement kvm_arch_test_clear_young() should override
> > + * kvm_arch_has_test_clear_young().
> > + *
> > + * kvm_arch_has_test_clear_young() is
On Fri, May 26, 2023 at 05:44:26PM -0600, Yu Zhao wrote:
> +/*
> + * Architectures that implement kvm_arch_test_clear_young() should override
> + * kvm_arch_has_test_clear_young().
> + *
> + * kvm_arch_has_test_clear_young() is allowed to return false positive,
> i.e., it
> + * can return true if
On Fri, May 26, 2023 at 05:44:26PM -0600, Yu Zhao wrote:
> @@ -122,6 +124,10 @@ struct mmu_notifier_ops {
> struct mm_struct *mm,
> unsigned long address);
>
> + int (*test_clear_young)(struct mmu_notifier *mn, struct mm_struct *mm,
> +
Add mmu_notifier_ops->test_clear_young() to supersede test_young()
and clear_young().
test_clear_young() has a fast path, which if supported, allows its
callers to safely clear the accessed bit without taking
kvm->mmu_lock.
The fast path requires arch-specific code that generally relies on
RCU
