On Mon, Sep 24, 2012 at 03:24:47PM +0900, Takuya Yoshikawa wrote: > This is an RFC since I have not done any comparison with the approach > using for_each_set_bit() which can be seen in Avi's work. > > Takuya > --- > > We did a simple test to see which requests we would get at the same time > in vcpu_enter_guest() and got the following numbers: > > |...........|...............|........|...............|.| > (N) (E) (S) (ES) others > 22.3% 30.7% 16.0% 29.5% 1.4% > > (N) : Nothing > (E) : Only KVM_REQ_EVENT > (S) : Only KVM_REQ_STEAL_UPDATE > (ES): Only KVM_REQ_EVENT and KVM_REQ_STEAL_UPDATE > > * Note that the exact numbers can change for other guests. > Yes, for guests that do not enable steal time KVM_REQ_STEAL_UPDATE should be never set, but currently it is. The patch (not tested) should fix this. diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 901ad00..01572f5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1544,6 +1544,8 @@ static void accumulate_steal_time(struct kvm_vcpu *vcpu) delta = current->sched_info.run_delay - vcpu->arch.st.last_steal; vcpu->arch.st.last_steal = current->sched_info.run_delay; vcpu->arch.st.accum_steal = delta; + + kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); } static void record_steal_time(struct kvm_vcpu *vcpu) @@ -1673,8 +1675,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) accumulate_steal_time(vcpu); preempt_enable(); - kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); - break; case MSR_KVM_PV_EOI_EN: if (kvm_lapic_enable_pv_eoi(vcpu, data)) @@ -2336,7 +2336,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) } accumulate_steal_time(vcpu); - kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
