On Tue, Jul 17, 2012 at 07:59:16AM -0600, Alex Williamson wrote: > On Tue, 2012-07-17 at 13:21 +0300, Michael S. Tsirkin wrote: > > On Mon, Jul 16, 2012 at 02:33:55PM -0600, Alex Williamson wrote: > > > + if (args->flags & KVM_EOIFD_FLAG_LEVEL_IRQFD) { > > > + struct _irqfd *irqfd = _irqfd_fdget_lock(kvm, args->irqfd); > > > + if (IS_ERR(irqfd)) { > > > + ret = PTR_ERR(irqfd); > > > + goto fail; > > > + } > > > + > > > + gsi = irqfd->gsi; > > > + level_irqfd = eventfd_ctx_get(irqfd->eventfd); > > > + source = _irq_source_get(irqfd->source); > > > + _irqfd_put_unlock(irqfd); > > > + if (!source) { > > > + ret = -EINVAL; > > > + goto fail; > > > + } > > > + } else { > > > + ret = -EINVAL; > > > + goto fail; > > > + } > > > + > > > + INIT_LIST_HEAD(&eoifd->list); > > > + eoifd->kvm = kvm; > > > + eoifd->eventfd = eventfd; > > > + eoifd->source = source; > > > + eoifd->level_irqfd = level_irqfd; > > > + eoifd->notifier.gsi = gsi; > > > + eoifd->notifier.irq_acked = eoifd_event; > > > > OK so this means eoifd keeps a reference to the irqfd. > > And since this is the case, can't we drop the reference counting > > around source ids now? Everything is referenced through irqfd. > > Holding a reference and using it as a reference count are not the same > thing. What if another module holds a reference to this eventfd? How > do we do anything on release? We don't as there is no release, and using kref on source id does not help: it just never gets invoked. -- MST -- 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