[dpdk-dev] [dpdk-users] RSS Hash not working for XL710/X710 NICs for some RX mbuf sizes
Take Ceara
dumitru.ceara at gmail.com
Tue Jul 26 10:38:22 CEST 2016
Hi Beilei,
On Mon, Jul 25, 2016 at 12:04 PM, Take Ceara <dumitru.ceara at gmail.com> wrote:
> Hi Beilei,
>
> On Mon, Jul 25, 2016 at 5:24 AM, Xing, Beilei <beilei.xing at intel.com> wrote:
>> Hi,
>>
>>> -----Original Message-----
>>> From: Take Ceara [mailto:dumitru.ceara at gmail.com]
>>> Sent: Friday, July 22, 2016 8:32 PM
>>> To: Xing, Beilei <beilei.xing at intel.com>
>>> Cc: Zhang, Helin <helin.zhang at intel.com>; Wu, Jingjing <jingjing.wu at intel.com>;
>>> dev at dpdk.org
>>> Subject: Re: [dpdk-dev] [dpdk-users] RSS Hash not working for XL710/X710 NICs
>>> for some RX mbuf sizes
>>>
>>> I was using the test-pmd "txonly" implementation which sends fixed UDP
>>> packets from 192.168.0.1:1024 -> 192.168.0.2:1024.
>>>
>>> I changed the test-pmd tx_only code so that it sends traffic with incremental
>>> destination IP: 192.168.0.1:1024 -> [192.168.0.2,
>>> 192.168.0.12]:1024
>>> I also dumped the source and destination IPs in the "rxonly"
>>> pkt_burst_receive function.
>>> Then I see that packets are indeed sent to different queues but the
>>> mbuf->hash.rss value is still 0.
>>>
>>> ./testpmd -c ffff1 -n 4 -w 0000:01:00.3 -w 0000:81:00.3 -- -i
>>> --coremask=0xffff0 --rxq=16 --txq=16 --mbuf-size 1152 --txpkts 1024
>>> --enable-rx-cksum --rss-udp
>>>
>>> [...]
>>>
>>> - Receive queue=0xf
>>> PKT_RX_RSS_HASH
>>> src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - type=0x0800 -
>>> length=1024 - nb_segs=1 - RSS queue=0xa - (outer) L2 type: ETHER -
>>> (outer) L3 type: IPV4_EXT_UNKNOWN SIP=C0A80001 DIP=C0A80006 - (outer)
>>> L4 type: UDP - Tunnel type: Unknown - RSS hash=0x0 - Inner L2 type:
>>> Unknown - RSS queue=0xf - RSS queue=0x7 - (outer) L2 type: ETHER -
>>> (outer) L3 type: IPV4_EXT_UNKNOWN SIP=C0A80001 DIP=C0A80007 - (outer)
>>> L4 type: UDP - Tunnel type: Unknown - Inner L2 type: Unknown - Inner
>>> L3 type: Unknown - Inner L4 type: Unknown
>>> - Receive queue=0x7
>>> PKT_RX_RSS_HASH
>>> src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - (outer) L2 type:
>>> ETHER - (outer) L3 type: IPV4_EXT_UNKNOWN SIP=C0A80001 DIP=C0A80009 -
>>> type=0x0800 - length=1024 - nb_segs=1 - Inner L3 type: Unknown - Inner
>>> L4 type: Unknown - RSS hash=0x0 - (outer) L4 type: UDP - Tunnel type:
>>> Unknown - Inner L2 type: Unknown - Inner L3 type: Unknown - RSS
>>> queue=0x7 - Inner L4 type: Unknown
>>>
>>> [...]
>>>
>>> testpmd> stop
>>> ------- Forward Stats for RX Port= 0/Queue= 0 -> TX Port= 1/Queue= 0 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 1 -> TX Port= 1/Queue= 1 -------
>>> RX-packets: 59 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 2 -> TX Port= 1/Queue= 2 -------
>>> RX-packets: 48 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 3 -> TX Port= 1/Queue= 3 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 4 -> TX Port= 1/Queue= 4 -------
>>> RX-packets: 59 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 5 -> TX Port= 1/Queue= 5 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 6 -> TX Port= 1/Queue= 6 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 7 -> TX Port= 1/Queue= 7 -------
>>> RX-packets: 48 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 8 -> TX Port= 1/Queue= 8 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue= 9 -> TX Port= 1/Queue= 9 -------
>>> RX-packets: 59 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=10 -> TX Port= 1/Queue=10 -------
>>> RX-packets: 48 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=11 -> TX Port= 1/Queue=11 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=12 -> TX Port= 1/Queue=12 -------
>>> RX-packets: 59 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=13 -> TX Port= 1/Queue=13 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=14 -> TX Port= 1/Queue=14 -------
>>> RX-packets: 0 TX-packets: 32 TX-dropped: 0
>>> ------- Forward Stats for RX Port= 0/Queue=15 -> TX Port= 1/Queue=15 -------
>>> RX-packets: 48 TX-packets: 32 TX-dropped: 0
>>> ---------------------- Forward statistics for port 0 ----------------------
>>> RX-packets: 428 RX-dropped: 84 RX-total: 512
>>> TX-packets: 0 TX-dropped: 0 TX-total: 0
>>> ----------------------------------------------------------------------------
>>>
>>> ---------------------- Forward statistics for port 1 ----------------------
>>> RX-packets: 0 RX-dropped: 0 RX-total: 0
>>> TX-packets: 512 TX-dropped: 0 TX-total: 512
>>> ----------------------------------------------------------------------------
>>>
>>> +++++++++++++++ Accumulated forward statistics for all
>>> ports+++++++++++++++
>>> RX-packets: 428 RX-dropped: 84 RX-total: 512
>>> TX-packets: 512 TX-dropped: 0 TX-total: 512
>>>
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> +++++++++++++++
>>>
>>> I checked all the RSS hash values for all the 10 different incoming streams and
>>> they're all 0. Also, the fact that the traffic is actually distributed seems to suggest
>>> that RSS itself is working but the mbuf hash field is (I guess) either not written or
>>> corrupted.
>>>
>>
>> I tried to reproduce the problem with the same steps you used on 16.04 and 16.07, but I really didn't replicate it.
>> I think you can try follow ways:
>> 1. apply the patch I told you last time and check if the problem still exists.
>
> I applied the changes in the patch manually to 16.04. The RSS=0
> problem still exists while the FDIR issue is fixed.
>
>> 2. update the codebase and check if the problem still exists.
>
> I updated the codebase to the latest version on
> http://dpdk.org/git/dpdk. I still see the RSS=0 issue.
>
>> 3. disable vector when you run testpmd, and check if the problem still exists.
>
> I recompiled the latest dpdk code with
> CONFIG_RTE_LIBRTE_I40E_INC_VECTOR=n and the RSS=0 issue is still
> there.
>
> My current command line is:
> ./testpmd -c ffff1 -n 4 -w 0000:01:00.3 -w 0000:81:00.3 -- -i
> --coremask=0xffff0 --rxq=16 --txq=16 --mbuf-size 1152 --txpkts 1024
> --rss-udp
>
> Not sure if relevant but I'm running kernel 4.2.0-27:
> $ uname -a
> Linux jspg2 4.2.0-27-generic #32~14.04.1-Ubuntu SMP Fri Jan 22
> 15:32:26 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
>
> Is there anything else that might help you identify the cause of the problem?
>
> Thanks,
> Dumitru
After some debugging in the i40e DPDK driver I figured out the problem
When receiving packets with i40e_recv_scattered_pkts, which gets
called in my case because the incoming packet is bigger than 1 full
mbuf (the 4 bytes CRC goes in the second mbuf of the chain), the
pkt_flags, hash, etc are set only when processing the last mbuf in the
packet chain. However, when the hash.rss field is set, instead of
setting it in the first mbuf of the packet it gets set in the current
mbuf (rxm). This can also cause a lot of unpredictable behavior if the
last mbuf only contained the CRC that was stripped as rxm would have
already been freed by then. The line I'm referring to is:
if (pkt_flags & PKT_RX_RSS_HASH)
rxm->hash.rss =
rte_le_to_cpu_32(rxd.wb.qword0.hi_dword.rss);
I changed it to setting the rss field in first_seg instead of rxm and
it works fine now.
As far as I see this is the only place where we can receive scattered
packets and all the other places where the RSS hash is set seem to be
fine.
Should I submit a proper patch for this or will you do it as you're
more familiar to the code?
Thanks,
Dumitru
>
>>
>>> >
>>> >>
>>> >> If I use a different mbuf-size, for example 2048, everything is fine:
>>> >>
>>> >> ./testpmd -c ffff1 -n 4 -w 0000:01:00.3 -w 0000:81:00.3 -- -i
>>> >> --coremask=0xffff0 --rxq=16 --txq=16 --mbuf-size 2048 --txpkts 1024
>>> >> -- enable-rx-cksum --rss-udp [...]
>>> >> testpmd> set verbose 1
>>> >> Change verbose level from 0 to 1
>>> >> testpmd> set fwd rxonly
>>> >> Set rxonly packet forwarding mode
>>> >> testpmd> start tx_first
>>> >> rxonly packet forwarding - CRC stripping disabled - packets/burst=32
>>> >> nb forwarding cores=16 - nb forwarding ports=2
>>> >> RX queues=16 - RX desc=128 - RX free threshold=32
>>> >> RX threshold registers: pthresh=8 hthresh=8 wthresh=0
>>> >> TX queues=16 - TX desc=512 - TX free threshold=32
>>> >> TX threshold registers: pthresh=32 hthresh=0 wthresh=0
>>> >> TX RS bit threshold=32 - TXQ flags=0xf01 port 0/queue 1: received
>>> >> 32 packets
>>> >> src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - type=0x0800 -
>>> >> length=1024 - nb_segs=1 - RSS hash=0x5263c3f2 - RSS queue=0x1 -
>>> >> (outer) L2 type: ETHER - (outer) L3 type: IPV4_EXT_UNKNOWN - (outer)
>>> >> L4 type: UDP - Tunnel type: Unknown - Inner L2 type: Unknown - Inner
>>> >> L3 type: Unknown - Inner L4 type: Unknown
>>> >> - Receive queue=0x1
>>> >> PKT_RX_RSS_HASH
>>> >>
>>> >
>>> > Did you send the same packet as before to port 0?
>>> >
>>> >> Another weird thing I noticed is when I run test-pmd without
>>> >> --enable-rx- cksum (which is the default mode) then the RSS flag doesn get
>>> set at all.
>>> >> Instead the PKT_RX_FDIR flag gets set. This happens even though
>>> >> fdir_mode is set to RTE_FDIR_MODE_NONE in the device
>>> >> configuration:
>>> >>
>>> >> ./testpmd -c ffff1 -n 4 -w 0000:01:00.3 -w 0000:81:00.3 -- -i
>>> >> --coremask=0xffff0 --rxq=16 --txq=16 --mbuf-size 1152 --txpkts 1024
>>> >> --rss- udp [...]
>>> >> testpmd> set verbose 1
>>> >> Change verbose level from 0 to 1
>>> >> testpmd> set fwd rxonly
>>> >> Set rxonly packet forwarding mode
>>> >> testpmd> start tx_first
>>> >> rxonly packet forwarding - CRC stripping disabled - packets/burst=32
>>> >> nb forwarding cores=16 - nb forwarding ports=2
>>> >> RX queues=16 - RX desc=128 - RX free threshold=32
>>> >> RX threshold registers: pthresh=8 hthresh=8 wthresh=0
>>> >> TX queues=16 - TX desc=512 - TX free threshold=32
>>> >> TX threshold registers: pthresh=32 hthresh=0 wthresh=0
>>> >> TX RS bit threshold=32 - TXQ flags=0xf01 port 0/queue 1: received
>>> >> 16 packets
>>> >> src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - type=0x0800 -
>>> >> length=1024 - nb_segs=2 - FDIR matched hash=0xc3f2 ID=0x5263 Unknown
>>> >> packet type
>>> >> - Receive queue=0x1
>>> >> PKT_RX_FDIR
>>> >> src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - type=0x0800 -
>>> >> length=1024 - nb_segs=2 - FDIR matched hash=0xc3f2 ID=0x5263 Unknown
>>> >> packet type
>>> >> - Receive queue=0x1
>>> >> PKT_RX_FDIR
>>> >>
>>> >
>>> > For this issue, I think following patch can solve your problem, please apply this
>>> patch.
>>> > http://dpdk.org/dev/patchwork/patch/13593/
>>> >
>>>
>>> I tried to apply it directly on 16.04 but it can't be applied. I see it's been applied to
>>> dpdk-next-net/rel_16_07. Do you happen to have one that would work on the
>>> latest stable 16.04 release?
>>
>> Sorry, I haven't. If there's conflict with R16.04, I think you can resolve it by going through the patch.
>>
>> Beilei
>>
>>>
>>> Thanks,
>>> Dumitru
>>>
>>> > Beilei
>>> >
>>> >> Please let me know if there's more debug info that might be of
>>> >> interest in troubleshooting the RSS=0 issue.
>>> >>
>>> >> Thanks,
>>> >> Dumitru
>>> >>
>>> >> > /Beilei
>>> >> >
>>> >> >> Thanks,
>>> >> >> Dumitru
>>> >> >>
>
>
>
> --
> Dumitru Ceara
--
Dumitru Ceara
More information about the dev
mailing list