[ovs-dev] [PATCH v2 08/15] connmgr: Make connmgr_wants_packet_in_on_miss() lock-free.

[Jarno Rajahalme]

> On Sep 1, 2016, at 4:35 PM, Jarno Rajahalme <jarno at ovn.org> wrote:
> 
> 
>> On Aug 29, 2016, at 2:49 PM, Ben Pfaff <blp at ovn.org> wrote:
>> 
>> On Mon, Aug 22, 2016 at 04:31:34PM -0700, Jarno Rajahalme wrote:
>>> Make connmgr_wants_packet_in_on_miss() use an atomic int instead of a
>>> list traversal taking the 'ofproto_mutex'.  This allows
>>> connmgr_wants_packet_in_on_miss() to be called also when
>>> 'ofproto_mutex' is already held, and makes it faster, too.
>>> 
>>> Remove unused ofproto_dpif_wants_packet_in_on_miss().
>>> 
>>> Signed-off-by: Jarno Rajahalme <jarno at ovn.org>
>> 
>> The logic doesn't seem right to me.  In ofconn_create() below,
>> ofconn_flush() always sets the protocol to OFPUTIL_P_NONE, so
>> update_want_packet_in_on_miss() will always treat the connection as one
>> that wants packet-ins.  Later on, the true OpenFlow version of the
>> connection will be learned (unless it drops quickly), but the count
>> won't be updated, but the call to update_want_packet_in_on_miss() from
>> ofconn_destroy() will behave differently depending on the version.
>> 
>>   ofconn_flush(ofconn);
>> 
>>   update_want_packet_in_on_miss(ofconn, true);
> 
> Oops, I totally missed the dynamic nature of this the first time around. I think I nailed it for the v2, though, updating the status after each ofconn_set_protocol() and ofconn_set_controller_id() change.
> 
>  Jarno
> 

Make that v3.

  Jarno