As requested by Glauber, do not update kvmclock area on vcpu->pcpu migration, in case the host has stable TSC. This is to reduce cacheline bouncing. Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Index: vsyscall/arch/x86/kvm/x86.c =================================================================== --- vsyscall.orig/arch/x86/kvm/x86.c +++ vsyscall/arch/x86/kvm/x86.c @@ -2615,7 +2615,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu kvm_x86_ops->write_tsc_offset(vcpu, offset); vcpu->arch.tsc_catchup = 1; } - kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); + /* + * On a host with synchronized TSC, there is no need to update + * kvmclock on vcpu->cpu migration + */ + if (!vcpu->kvm->arch.use_master_clock || vcpu->cpu == -1) + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); if (vcpu->cpu != cpu) kvm_migrate_timers(vcpu); vcpu->cpu = cpu; -- 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
