[ovs-dev] [PATCH v3 0/4] dpcls subtable miniflow optimizations

[Van Haaren, Harry]

> -----Original Message-----
> From: Ilya Maximets [mailto:i.maximets at samsung.com]
> Sent: Wednesday, November 21, 2018 10:14 PM
> To: Van Haaren, Harry <harry.van.haaren at intel.com>; ovs-dev at openvswitch.org
> Cc: Stokes, Ian <ian.stokes at intel.com>; echaudro at redhat.com; Wang, Yipeng1
> <yipeng1.wang at intel.com>
> Subject: Re: [PATCH v3 0/4] dpcls subtable miniflow optimizations
> 
> On 21.11.2018 4:39, Harry van Haaren wrote:
> > Hi Folks,
> >

<snip>

> >
> > Performance:
> > Patches 1, 2 and 3 are performance neutral in testing here. The
> > fourth patch provides a significant performance improvement when
> > dpcls or SMC are processing packets.
> >
> > Feedback, reviews, performance numbers weclomed! -Harry
> 
> Hi Harry,
> Thanks for your work on this.
> I didn't look at the code yet. Just wanted to make some preliminary tests.
> By the first impression this patch set improves my usual scenario by 5-8%.
> That is good result. But I observed the issue when I tried to enable SMC.
> 
> My case is the VM(vhu0) --> balanced_tcp_bond(ens1f0, ens1f1).
> Usually, If I'm sending 8 flows from the VM I have following flows installed:

Hi Ilya,

<snip away rules>

> But, from time to time, If I enable SMC with:
> # ovs-vsctl set Open_vSwitch . other_config:smc-enable=true
> 
> all the packets starts to match with a single installed flow:
> 
> flow-dump from pmd on cpu core: 2
> recirc_id(0x1),dp_hash(0xe46d47f9/0xff),in_port(vhu0),packet_type(ns=0,id=0),e
> th_type(0x8100),vlan(vid=2055,pcp=0),encap(eth_type(0x0800),ipv4(frag=no)),
> packets:215076660, bytes:108510095624, used:0.000s, actions:ens1f0
> 
> All other flows expired.
> 
> And it's definitely not right thing to happen. i.e. all packets starts
> matching
> with a single rule ignoring the recirculation id, vlan tag and the dp_hash
> field.
> That leads to sending them directly to one of the physical ports without
> pushing
> vlan tag and without recirculation.
> And I actually see these packets on the physical network.
> 
> When the SMC disabled back, traffic becomes normal again.

Thanks for reporting - I'll make a similar test setup here and try to
reproduce.

I've looked at making a set of unit tests for dpcls / miniflow extract,
which would be quiet useful to verify the dpcls_rule_matches_key() changes
here. Perhaps it makes to include them in this patchset too!

Thanks again, -Harry