[ovs-discuss] There's no available (non-isolated) pmd thread on numa node 0, Expect reduced performance.

Stokes, Ian ian.stokes at intel.com
Thu Apr 12 16:28:31 UTC 2018


Hi,

I was able to reproduce the issue on my system.

As you are setting all lcore and pmd core to node 1 why are you giving 1024 memory to node 0?

I saw the same issue on my system but the warning did not appear once memory was allocated to node 1 only.

I would think the VM being launched is using memory for the vhost port from node 0, however the queue for the vhost port is assigned to core 14 which is on node1. When processing packets for this port it means cpu is accessing data across the numa nodes which causes a performance penalty, hence the warning.

To avoid you should ensure all memory and cores operate on the same node where possible, try using ‘other_config:dpdk-socket-mem=0,4096’ and see if you still see the issue.

Thanks
Ian

From: ovs-discuss-bounces at openvswitch.org [mailto:ovs-discuss-bounces at openvswitch.org] On Behalf Of Alan Kayahan
Sent: Thursday, April 12, 2018 2:27 AM
To: ovs-discuss at openvswitch.org
Subject: [ovs-discuss] There's no available (non-isolated) pmd thread on numa node 0, Expect reduced performance.

Hello,

On the following setup, where all cores but 0 are isolated,

available: 2 nodes (0-1)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9
node 1 cpus: 10 11 12 13 14 15 16 17 18 19

I am trying to start OVS entirely on numa node 1 as following

ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-init=true other_config:dpdk-lcore-mask=0x00400 other_config:pmd-cpu-mask=0xffc00 other_config:dpdk-socket-mem=1024,4096

However when I create a vhost port SRC to attach a VNF(via virtio) on node 0, I get the following

dpif_netdev|WARN|There's no available (non-isolated) pmd thread on numa node 0. Queue 0 on port 'SRC' will be assigned to the pmd on core 14 (numa node 1). Expect reduced performance.

Any ideas?

Thanks
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