Ben, Sorry for the delay.
In the struct dp_netdev, there are two members, struct dp_netdev_port
*ports[MAX_PORTS] and struct list port_list, which mean the ports of this
datapath, also a switch. And in the snippet code of function
dpif_netdev_run():
--------------------------------------------------------------------
LIST_FOR_EACH (port, node, &dp->port_list)
--------------------------------------------------------------------
so dp->port_list represents the input ports of the datapath. Then following
the call stack, here is the code of function dp_netdev_output_port():
-------------------------------------------------------------------
struct dp_netdev_port *p = dp->ports[out_port];
if (p) {
netdev_send(p->netdev, packet);
}
------------------------------------------------------------------
So this dp->ports represent the output ports of the datapath. Is that
correct?
Cheers,
Jfhu
2012/3/9 Ben Pfaff <b...@nicira.com>
> What is "the output ports list" and "the input ports list"? I don't
> know what list (lists?) you mean.
>
> On Thu, Mar 08, 2012 at 08:35:38PM +0800, HuJingfei wrote:
> >
> > Thanks, Ben,Exactly speaking, it's the loop of function
> > dpif_netdev_run() that does the packets scheduling. Now, I know that
> > the next procedure of normal process is: dpif_netdev_run() ->
> > dp_netdev_port_input() -> dp_netdev_execute_actions() ->
> > dp_netdev_output_port()But what confuses me is that why the output
> > ports list is the same with input ports list? Is that scan?
> > Cheers,
> > Jfhu
> > > Date: Wed, 7 Mar 2012 08:00:06 -0800
> > > From: b...@nicira.com
> > > To: hujingfei...@msn.com
> > > CC: discuss@openvswitch.org
> > > Subject: Re: [ovs-discuss] Switch architecture of OVS userspace switch
> > >
> > > Since you are specifically interested in the userspace OVS switch, you
> > > can just follow the process of the loop in dpif_run(). Each iteration
> > > of the loop fully processes one packet.
> > >
> > > On Wed, Mar 07, 2012 at 03:56:03PM +0800, HuJingfei wrote:
> > > >
> > > > Thanks, Ben, I appreciate your help very much.Is there any
> > > > documentation or schematic diagram that describes the process that a
> > > > packet entering the switch's input ports, scheduling, and departing
> > > > from the switch's output ports? Or there is no such stuff in OVS？
> > > > Cheers,
> > > > Jfhu> Date: Tue, 6 Mar 2012 21:37:32 -0800
> > > > > From: b...@nicira.com
> > > > > To: hujingfei...@msn.com
> > > > > CC: discuss@openvswitch.org
> > > > > Subject: Re: [ovs-discuss] Switch architecture of OVS userspace
> switch
> > > > >
> > > > > On Wed, Mar 07, 2012 at 11:35:57AM +0800, HuJingfei wrote:
> > > > > >
> > > > > >
> > > > > > Thanks, Ben, All right. However, at least there is a mapping
> from the
> > > > > > software implementation of a switch to its real component. Is
> that
> > > > > > right? For example,The struct, dp_netdev, may be mapped to a
> switch,
> > > > > > because of following mappings:1. member struct dp_netdev_queue
> > > > > > queues[N_QUEUES] corresponds to actual buffer of a switch, every
> > > > > > packet from input ports will enter this buffer first, then will
> be
> > > > > > scheduled to go to its destined output port.
> > > > >
> > > > > No, that's wrong, that's not at all how these queues are used.
> These
> > > > > queues are used to respond to dpif_recv(). Please read the
> > > > > documentation for that function to obtain more insight.
> > > > >
> > > > > > 2. member struct dp_netdev_port *ports[MAX_PORTS] corresponds to
> > > > > > actual ports of a switch.
> > > > >
> > > > > Yes, that is correct.
> > > > >
> > > > > > Please correct me if I am wrong. Cheers,Jfhu
> > > > > > > Date: Tue, 6 Mar 2012 14:17:57 -0800
> > > > > > > From: b...@nicira.com
> > > > > > > To: hujingfei...@msn.com
> > > > > > > CC: discuss@openvswitch.org
> > > > > > > Subject: Re: [ovs-discuss] Switch architecture of OVS
> userspace switch
> > > > > > >
> > > > > > > On Tue, Mar 06, 2012 at 11:35:42AM +0800, HuJingfei wrote:
> > > > > > > >
> > > > > > > > Hi, all,I'm newbie to OVS. I know there are quite a lot of
> switch
> > > > > > > > architectures such as Shared Memory, Shared Medium,
> Crossbar, Banyan
> > > > > > > > and so on. Could anyone tell me the userspace OVS switch's
> > > > > > > > architecture please? Forgive me for my stupid question.
> Cheers, Jfhu
> > > > > > >
> > > > > > > It's a piece of software, not a piece of hardware, so it's not
> > > > > > > meaningful to try to classify it in terms of hardware designs.
> > > > > >
> > > >
> >
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>
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