[ovs-discuss] Fwd: [ovs-dpdk] bandwidth issue of vhostuserclient virtio ovs-dpdk

LIU Yulong liuyulong.xa at gmail.com
Fri Nov 30 02:07:24 UTC 2018


Hi,

Thanks for the reply, please see my inline comments below.


On Thu, Nov 29, 2018 at 6:00 PM Lam, Tiago <tiago.lam at intel.com> wrote:

> On 29/11/2018 08:24, LIU Yulong wrote:
> > Hi,
> >
> > We recently tested ovs-dpdk, but we met some bandwidth issue. The
> bandwidth
> > from VM to VM was not close to the physical NIC, it's about 4.3Gbps on a
> > 10Gbps NIC. For no dpdk (virtio-net) VMs, the iperf3 test can easily
> > reach 9.3Gbps. We enabled the virtio multiqueue for all guest VMs. In the
> > dpdk vhostuser guest, we noticed that the interrupts are centralized to
> > only one queue. But for no dpdk VM, interrupts can hash to all queues.
> > For those dpdk vhostuser VMs, we also noticed that the PMD usages were
> > also centralized to one no matter server(tx) or client(rx). And no matter
> > one PMD or multiple PMDs, this behavior always exists.
> >
> > Furthuremore, my colleague add some systemtap hook on the openvswitch
> > function, he found something interesting. The function
> > __netdev_dpdk_vhost_send will send all the packets to one
> virtionet-queue.
> > Seems that there are some algorithm/hash table/logic does not do the hash
> > very well.
> >
>
> Hi,
>
> When you say "no dpdk VMs", you mean that within your VM you're relying
> on the Kernel to get the packets, using virtio-net. And when you say
> "dpdk vhostuser guest", you mean you're using DPDK inside the VM to get
> the packets. Is this correct?


Sorry for the inaccurate description. I'm really new to DPDK.
No DPDK inside VM, all these settings are for host only.
(`host` means the hypervisor physical machine in the perspective of
virtualization.
On the other hand `guest` means the virtual machine.)
"no dpdk VMs" means the host does not setup DPDK (ovs is working in
traditional way),
the VMs were boot on that. Maybe a new name `VMs-on-NO-DPDK-host`?

If so, could you also tell us which DPDK app you're using inside of
> those VMs? Is it testpmd? If so, how are you setting the `--rxq` and
> `--txq` args? Otherwise, how are you setting those in your app when
> initializing DPDK?
>

Inside VM, there is no DPDK app, VM kernel also
does not set any config related to DPDK. `iperf3` is the tool for bandwidth
testing.

The information below is useful in telling us how you're setting your
> configurations in OvS, but we are still missing the configurations
> inside the VM.
>
> This should help us in getting more information,
>
>
Maybe you have noticed that, we only setup one PMD in the pasted
configurations.
But VM has 8 queues. Should the pmd quantity match the queues?

Tiago.
>
> > So I'd like to find some help from the community. Maybe I'm missing some
> > configrations.
> >
> > Thanks.
> >
> >
> > Here is the list of the environment and some configrations:
> > # uname -r
> > 3.10.0-862.11.6.el7.x86_64
> > # rpm -qa|grep dpdk
> > dpdk-17.11-11.el7.x86_64
> > # rpm -qa|grep openvswitch
> > openvswitch-2.9.0-3.el7.x86_64
> > # ovs-vsctl list open_vswitch
> > _uuid               : a6a3d9eb-28a8-4bf0-a8b4-94577b5ffe5e
> > bridges             : [531e4bea-ce12-402a-8a07-7074c31b978e,
> > 5c1675e2-5408-4c1f-88bc-6d9c9b932d47]
> > cur_cfg             : 1305
> > datapath_types      : [netdev, system]
> > db_version          : "7.15.1"
> > external_ids        : {hostname="cq01-compute-10e112e5e140",
> > rundir="/var/run/openvswitch",
> > system-id="e2cc84fe-a3c8-455f-8c64-260741c141ee"}
> > iface_types         : [dpdk, dpdkr, dpdkvhostuser, dpdkvhostuserclient,
> > geneve, gre, internal, lisp, patch, stt, system, tap, vxlan]
> > manager_options     : [43803994-272b-49cb-accc-ab672d1eefc8]
> > next_cfg            : 1305
> > other_config        : {dpdk-init="true", dpdk-lcore-mask="0x1",
> > dpdk-socket-mem="1024,1024", pmd-cpu-mask="0x100000",
> > vhost-iommu-support="true"}
> > ovs_version         : "2.9.0"
> > ssl                 : []
> > statistics          : {}
> > system_type         : centos
> > system_version      : "7"
> > # lsmod |grep vfio
> > vfio_pci               41312  2
> > vfio_iommu_type1       22300  1
> > vfio                   32695  7 vfio_iommu_type1,vfio_pci
> > irqbypass              13503  23 kvm,vfio_pci
> >
> > # ovs-appctl dpif/show
> > netdev at ovs-netdev: hit:759366335 missed:754283
> > br-ex:
> > bond1108 4/6: (tap)
> > br-ex 65534/3: (tap)
> > nic-10G-1 5/4: (dpdk: configured_rx_queues=8,
> > configured_rxq_descriptors=2048, configured_tx_queues=2,
> > configured_txq_descriptors=2048, mtu=1500, requested_rx_queues=8,
> > requested_rxq_descriptors=2048, requested_tx_queues=2,
> > requested_txq_descriptors=2048, rx_csum_offload=true)
> > nic-10G-2 6/5: (dpdk: configured_rx_queues=8,
> > configured_rxq_descriptors=2048, configured_tx_queues=2,
> > configured_txq_descriptors=2048, mtu=1500, requested_rx_queues=8,
> > requested_rxq_descriptors=2048, requested_tx_queues=2,
> > requested_txq_descriptors=2048, rx_csum_offload=true)
> > phy-br-ex 3/none: (patch: peer=int-br-ex)
> > br-int:
> > br-int 65534/2: (tap)
> > int-br-ex 1/none: (patch: peer=phy-br-ex)
> > vhu76f9a623-9f 2/1: (dpdkvhostuserclient: configured_rx_queues=8,
> > configured_tx_queues=8, mtu=1500, requested_rx_queues=8,
> > requested_tx_queues=8)
> >
> > # ovs-appctl dpctl/show -s
> > netdev at ovs-netdev:
> > lookups: hit:759366335 missed:754283 lost:72
> > flows: 186
> > port 0: ovs-netdev (tap)
> > RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:0 errors:0 dropped:0 aborted:0 carrier:0
> > collisions:0
> > RX bytes:0  TX bytes:0
> > port 1: vhu76f9a623-9f (dpdkvhostuserclient: configured_rx_queues=8,
> > configured_tx_queues=8, mtu=1500, requested_rx_queues=8,
> > requested_tx_queues=8)
> > RX packets:718391758 errors:0 dropped:0 overruns:? frame:?
> > TX packets:30372410 errors:? dropped:719200 aborted:? carrier:?
> > collisions:?
> > RX bytes:1086995317051 (1012.3 GiB)  TX bytes:2024893540 (1.9 GiB)
> > port 2: br-int (tap)
> > RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:1393992 errors:0 dropped:4 aborted:0 carrier:0
> > collisions:0
> > RX bytes:0  TX bytes:2113616736 (2.0 GiB)
> > port 3: br-ex (tap)
> > RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:6660091 errors:0 dropped:967 aborted:0 carrier:0
> > collisions:0
> > RX bytes:0  TX bytes:2451440870 (2.3 GiB)
> > port 4: nic-10G-1 (dpdk: configured_rx_queues=8,
> > configured_rxq_descriptors=2048, configured_tx_queues=2,
> > configured_txq_descriptors=2048, mtu=1500, requested_rx_queues=8,
> > requested_rxq_descriptors=2048, requested_tx_queues=2,
> > requested_txq_descriptors=2048, rx_csum_offload=true)
> > RX packets:36409466 errors:0 dropped:0 overruns:? frame:?
> > TX packets:718371472 errors:0 dropped:20276 aborted:? carrier:?
> > collisions:?
> > RX bytes:2541593983 (2.4 GiB)  TX bytes:1089838136919 (1015.0 GiB)
> > port 5: nic-10G-2 (dpdk: configured_rx_queues=8,
> > configured_rxq_descriptors=2048, configured_tx_queues=2,
> > configured_txq_descriptors=2048, mtu=1500, requested_rx_queues=8,
> > requested_rxq_descriptors=2048, requested_tx_queues=2,
> > requested_txq_descriptors=2048, rx_csum_offload=true)
> > RX packets:5319466 errors:0 dropped:0 overruns:? frame:?
> > TX packets:0 errors:0 dropped:0 aborted:? carrier:?
> > collisions:?
> > RX bytes:344903551 (328.9 MiB)  TX bytes:0
> > port 6: bond1108 (tap)
> > RX packets:228 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:5460 errors:0 dropped:18 aborted:0 carrier:0
> > collisions:0
> > RX bytes:21459 (21.0 KiB)  TX bytes:341087 (333.1 KiB)
> >
> > # ovs-appctl dpif-netdev/pmd-stats-show
> > pmd thread numa_id 0 core_id 20:
> > packets received: 760120690
> > packet recirculations: 0
> > avg. datapath passes per packet: 1.00
> > emc hits: 750787577
> > megaflow hits: 8578758
> > avg. subtable lookups per megaflow hit: 1.05
> > miss with success upcall: 754283
> > miss with failed upcall: 72
> > avg. packets per output batch: 2.21
> > idle cycles: 210648140144730 (99.13%)
> > processing cycles: 1846745927216 (0.87%)
> > avg cycles per packet: 279554.14 (212494886071946/760120690)
> > avg processing cycles per packet: 2429.54 (1846745927216/760120690)
> > main thread:
> > packets received: 0
> > packet recirculations: 0
> > avg. datapath passes per packet: 0.00
> > emc hits: 0
> > megaflow hits: 0
> > avg. subtable lookups per megaflow hit: 0.00
> > miss with success upcall: 0
> > miss with failed upcall: 0
> > avg. packets per output batch: 0.00
> >
> > # ovs-appctl dpif-netdev/pmd-rxq-show
> > pmd thread numa_id 0 core_id 20:
> > isolated : false
> > port: nic-10G-1       queue-id:  0pmd usage:  0 %
> > port: nic-10G-1       queue-id:  1pmd usage:  0 %
> > port: nic-10G-1       queue-id:  2pmd usage:  0 %
> > port: nic-10G-1       queue-id:  3pmd usage:  0 %
> > port: nic-10G-1       queue-id:  4pmd usage:  0 %
> > port: nic-10G-1       queue-id:  5pmd usage:  0 %
> > port: nic-10G-1       queue-id:  6pmd usage:  0 %
> > port: nic-10G-1       queue-id:  7pmd usage:  0 %
> > port: nic-10G-2       queue-id:  0pmd usage:  0 %
> > port: nic-10G-2       queue-id:  1pmd usage:  0 %
> > port: nic-10G-2       queue-id:  2pmd usage:  0 %
> > port: nic-10G-2       queue-id:  3pmd usage:  0 %
> > port: nic-10G-2       queue-id:  4pmd usage:  0 %
> > port: nic-10G-2       queue-id:  5pmd usage:  0 %
> > port: nic-10G-2       queue-id:  6pmd usage:  0 %
> > port: nic-10G-2       queue-id:  7pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  0pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  1pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  2pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  3pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  4pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  5pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  6pmd usage:  0 %
> > port: vhu76f9a623-9f  queue-id:  7pmd usage:  0 %
> >
> >
> > # virsh dumpxml instance-5c5191ff-c1a2-4429-9a8b-93ddd939583d
> > ...
> >     <interface type='vhostuser'>
> >       <mac address='fa:16:3e:77:ab:fb'/>
> >       <source type='unix' path='/var/lib/vhost_sockets/vhu76f9a623-9f'
> > mode='server'/>
> >       <target dev='vhu76f9a623-9f'/>
> >       <model type='virtio'/>
> >       <driver name='vhost' queues='8'/>
> >       <alias name='net0'/>
> >       <address type='pci' domain='0x0000' bus='0x00' slot='0x03'
> > function='0x0'/>
> >     </interface>
> > ...
> >
> > # ovs-vsctl show
> > a6a3d9eb-28a8-4bf0-a8b4-94577b5ffe5e
> >     Manager "ptcp:6640:127.0.0.1"
> >         is_connected: true
> >     Bridge br-int
> >         Controller "tcp:127.0.0.1:6633 <http://127.0.0.1:6633>"
> >             is_connected: true
> >         fail_mode: secure
> >         Port int-br-ex
> >             Interface int-br-ex
> >                 type: patch
> >                 options: {peer=phy-br-ex}
> >         Port br-int
> >             Interface br-int
> >                 type: internal
> >         Port "vhu76f9a623-9f"
> >             tag: 1
> >             Interface "vhu76f9a623-9f"
> >                 type: dpdkvhostuserclient
> >                 options: {n_rxq="8",
> > vhost-server-path="/var/lib/vhost_sockets/vhu76f9a623-9f"}
> >     Bridge br-ex
> >         Controller "tcp:127.0.0.1:6633 <http://127.0.0.1:6633>"
> >             is_connected: true
> >         fail_mode: secure
> >         Port dpdkbond
> >             Interface "nic-10G-1"
> >                 type: dpdk
> >                 options: {dpdk-devargs="0000:01:00.0", n_rxq="8",
> n_txq="8"}
> >             Interface "nic-10G-2"
> >                 type: dpdk
> >                 options: {dpdk-devargs="0000:05:00.1", n_rxq="8",
> n_txq="8"}
> >         Port phy-br-ex
> >             Interface phy-br-ex
> >                 type: patch
> >                 options: {peer=int-br-ex}
> >         Port br-ex
> >             Interface br-ex
> >                 type: internal
> >
> > # numactl --hardware
> > available: 2 nodes (0-1)
> > node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
> > node 0 size: 130978 MB
> > node 0 free: 7539 MB
> > node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
> > node 1 size: 131072 MB
> > node 1 free: 6886 MB
> > node distances:
> > node   0   1
> >   0:  10  21
> >   1:  21  10
> >
> > # grep HugePages_ /proc/meminfo
> > HugePages_Total:     232
> > HugePages_Free:       10
> > HugePages_Rsvd:        0
> > HugePages_Surp:        0
> >
> >
> > # cat /proc/cmdline
> > BOOT_IMAGE=/boot/vmlinuz-3.10.0-862.11.6.el7.x86_64
> > root=UUID=220ee106-5e00-4809-91a0-641e045a4c21 ro
> > intel_idle.max_cstate=0 crashkernel=auto rhgb quiet
> > default_hugepagesz=1G hugepagesz=1G hugepages=232 iommu=pt intel_iommu=on
> >
> >
> > Best regards,
> > LIU Yulong
> >
> > _______________________________________________
> > discuss mailing list
> > discuss at openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> >
>
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