SCHEDSTATS provide a precise source of information about time tasks spent on a runqueue, but not running (among other things). It is specially useful for the steal time implementation, because it doesn't record halt time at all.
To avoid a hard dependency on schedstats, since it is possible one won't want to record statistics about all processes running, the previous method of time measurement on put/load vcpu is kept for !SCHEDSTATS. Signed-off-by: Glauber Costa <[email protected]> CC: Rik van Riel <[email protected]> CC: Jeremy Fitzhardinge <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Avi Kivity <[email protected]> CC: Anthony Liguori <[email protected]> CC: Eric B Munson <[email protected]> CC: Marcelo Tosatti <[email protected]> --- arch/x86/kvm/x86.c | 22 ++++++++++++++++++---- 1 files changed, 18 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index df9d274..7e87159 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1502,7 +1502,13 @@ static void record_steal_time(struct kvm_vcpu *vcpu) &vcpu->arch.st.steal, sizeof(struct kvm_steal_time)))) return; - delta = (get_kernel_ns() - vcpu->arch.st.this_time_out); +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) + if (likely(sched_info_on())) { + delta = current->sched_info.run_delay - vcpu->arch.st.this_time_out; + vcpu->arch.st.this_time_out = current->sched_info.run_delay; + } else +#endif + delta = (get_kernel_ns() - vcpu->arch.st.this_time_out); vcpu->arch.st.steal.steal += delta; vcpu->arch.st.steal.version += 2; @@ -1607,9 +1613,14 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) data & KVM_STEAL_VALID_BITS)) return 1; - vcpu->arch.st.this_time_out = get_kernel_ns(); - record_steal_time(vcpu); +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) + if (likely(sched_info_on())) + vcpu->arch.st.this_time_out = current->sched_info.run_delay; + else +#endif + vcpu->arch.st.this_time_out = get_kernel_ns(); + record_steal_time(vcpu); break; case MSR_IA32_MCG_CTL: @@ -2220,7 +2231,10 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_x86_ops->vcpu_put(vcpu); kvm_put_guest_fpu(vcpu); kvm_get_msr(vcpu, MSR_IA32_TSC, &vcpu->arch.last_guest_tsc); - vcpu->arch.st.this_time_out = get_kernel_ns(); +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) + if (unlikely(!sched_info_on())) +#endif + vcpu->arch.st.this_time_out = get_kernel_ns(); } static int is_efer_nx(void) -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
