[dpdk-dev] [dpdk-users] RSS Hash not working for XL710/X710 NICs for some RX mbuf sizes

Take Ceara dumitru.ceara at gmail.com
Fri Jul 22 14:31:40 CEST 2016


Hi Beilei,

On Fri, Jul 22, 2016 at 11:04 AM, Xing, Beilei <beilei.xing at intel.com> wrote:
> Hi Ceara,
>
>> -----Original Message-----
>> From: Take Ceara [mailto:dumitru.ceara at gmail.com]
>> Sent: Thursday, July 21, 2016 6:58 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
>>
>>
>> Following your testpmd example run I managed to replicate the problem on
>> my dpdk 16.04 setup like this:
>>
>> I have two X710 adapters connected back to back:
>> $ ./tools/dpdk_nic_bind.py -s
>>
>> Network devices using DPDK-compatible driver
>> ============================================
>> 0000:01:00.3 'Ethernet Controller X710 for 10GbE SFP+' drv=igb_uio unused=
>> 0000:81:00.3 'Ethernet Controller X710 for 10GbE SFP+' drv=igb_uio unused=
>>
>> The firmware of the two adapters is up to date with the latest
>> version: 5.04 (f5.0.40043 a1.5 n5.04 e24cd)
>>
>> I run testpmd with mbuf-size 1152 and txpktsize 1024 such that upon receival
>> the whole mbuf (except headroom) is filled.
>> I enabled RX IP checksum in hw and RX RSS hashing for UDP.
>> With test-pmd forward mode "rxonly" and verbose 1 I see that incoming
>> packets have PKT_RX_RSS_HASH set but the hash value is 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 [...]
>> 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=0x0 - 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
>>   src=68:05:CA:38:6D:63 - dst=02:00:00:00:00:01 - type=0x0800 -
>> length=1024 - nb_segs=1 - RSS hash=0x0 - 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
>
> What's the source ip address and destination ip address of the packet you sent to port 0? Could you try to change ip address or port number to observe if hash value changes? I remember I saw hash value was 0 before, but with different ip address, there'll be different hash values.

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.

>
>>
>> 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?

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
>> >>


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