Re: [Qemu-devel] [PATCH v2 1/5] net: spread hub on AioContexts

[Paolo Bonzini]

Il 13/03/2013 03:26, liu ping fan ha scritto:
>>> >> +        qemu_net_queue_append(port->nc.peer->send_queue, &port->nc,
>>> >> +                            QEMU_NET_PACKET_FLAG_NONE, buf, len, NULL);
>>> >> +        event_notifier_set(&port->e);
>> >
>> > Why are the context and the EventNotifier a property of the port, rather
>> > than applicable to the NetClientState?
>> >
> Yes, embed context into NetClientState is more reasonable, but as for
> EventNotifier, considering about if we port tap onto context, the tap
> do not have EventNotifier.
> 

There doesn't even need to be an EventNotifier, instead you can pass the
NetClientState's AioContext to the queue and use a bottom half on the
AioContext.

Furthermore, the bottom half should be completely transparent.  Callers
can keep using qemu_net_queue_flush, qemu_net_queue_flush schedules the
bottom half (perhaps, with an optimization, it only does that if the
queue is not empty), the handler actually performs the flush.

Paolo