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? Paolo -- 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
