Re: [PATCH] KVM: MMU: increment stats after event occurrence

Takuya Yoshikawa
2012-01-13T01:22:58Z

(2012/01/13 10:08), Davidlohr Bueso wrote:
> From: Davidlohr Bueso<dave@gnu.org>
>
> It makes more sense to actually increment statistics for tlb flushes and page table entry updates after such _events_ occur, instead of before.

Why?

Takuya

>
> Signed-off-by: Davidlohr Bueso<dave@gnu.org>
> ---
> arch/x86/kvm/mmu.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 2a2a9b4..0b7008e 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -3130,8 +3130,8 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu,
>
> void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
> {
> - ++vcpu->stat.tlb_flush;
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
> + ++vcpu->stat.tlb_flush;
> }
>
> static void paging_new_cr3(struct kvm_vcpu *vcpu)
> @@ -3486,8 +3486,8 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
> return;
> }
>
> - ++vcpu->kvm->stat.mmu_pte_updated;
> vcpu->arch.mmu.update_pte(vcpu, sp, spte, new);
> + ++vcpu->kvm->stat.mmu_pte_updated;
> }
>
> static bool need_remote_flush(u64 old, u64 new)