[Xorp-hackers] Update FEA patch for one-socket per descriptor.

[Ben Greear]

Pavlin Radoslavov wrote:
> Ben Greear <greearb at candelatech.com> wrote:
> 
>> An updated patch is attached.  This patch also includes
>> logic to clean up multicast bindings on interface removal
>> and code to set the rx buffer for the tx-only socket very
>> small.
> 
> Now that we have the pif_index optimized search in place, what are
> the performance numbers with and without the "one socket per
> interface" patch?

I'll try to run these sometime soon.

>> The multicast changes fix a race in interface removal
>> (iface is removed before OSPF notices and removes the
>> multicast binds, and since the iface is gone, fea can no
>> longer run the unbind logic.)  This is probably less
>> critical when running one socket per iface, since the
>> entire socket will already be cleaned up.
> 
> Is this a race that is in the vanilla FEA?
> If yes, what is the sequence of events/commands we can use to
> reproduce it?

Yes.  I think all you have to do is remove an interface
that was previously configured via xorpsh from the interface
cfg, commit, then remove it from ospf config.  When
you remove it from ospf, it tries to unregister the multicast
addrs, but fea has already deleted the iface, so it cannot
figure out how to unregister.

We discussed this months ago..I'll try to find those emails,
as the above scenario is just from memory....

> In any case, as discussed previously, please create a Bugzilla entry
> and add your patch to it.
> There will be more refactoring in the FEA, so during that
> refactoring your patch can be considered as well.

Sounds good.

Thanks,
Ben

> 
> Thanks,
> Pavlin


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com