Am 30.07.2015 um 16:02 schrieb Paolo Bonzini: > > > On 30/07/2015 15:57, Christian Borntraeger wrote: >>>>>> + /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case >>>>>> + * the caller has read kvm->online_vcpus before (as is the case >>>>>> + * for kvm_for_each_vcpu, for example). >>>>>> + */ >> is somewhat distracting because of "read" and "before". So something like >> >> /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, to serialize the setting >> of kvm->vcpus and setting kvm->online_vcpus.... >> >> might be better. > > What you are suggesting would go in kvm_vm_ioctl_create_vcpu, e.g. > rewriting: > > /* Pairs with smp_rmb() in kvm_get_vcpu. */ > smp_wmb(); > > like this: > > /* > * Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus > * before kvm->online_vcpu's incremented value. > */ > smp_wmb(); > > Instead, kvm_get_cpu has: > > /* > * Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case > * the caller has read kvm->online_vcpus before (as is the case > * for kvm_for_each_vcpu, for example). > */ > smp_rmb(); > > which already describes which loads are serialized here. > > Is this correct? Right you are. -- 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
