Re: [PATCH RFC V3 2/3] kvm: Note down when cpu relax interceptedor pause loop exited

From: Christian Borntraeger
Date: Thu Jul 12 2012 - 16:02:43 EST


On 12/07/12 21:18, Raghavendra K T wrote:
> +#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
[...]
> + struct {
> + bool cpu_relax_intercepted;
> + bool dy_eligible;
> + } ple;
> +#endif
[...]
> }
> vcpu->run = page_address(page);
> + vcpu->ple.cpu_relax_intercepted = false;
> + vcpu->ple.dy_eligible = false;

This struct is only defined if CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT is set, but here it
is always accessed. Will break on !x86 && !s390.
>
> r = kvm_arch_vcpu_init(vcpu);
> if (r < 0)
> @@ -1577,6 +1579,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
> int pass;
> int i;
>
> + me->ple.cpu_relax_intercepted = true;

dito
> /*
> * We boost the priority of a VCPU that is runnable but not
> * currently running, because it got preempted by something
> @@ -1602,6 +1605,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
> }
> }
> }
> + me->ple.cpu_relax_intercepted = false;

again.

maybe define static inline access functions in kvm_host.h that are no-ops
if CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT is not set.

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