On 28.02.2017 14:43, O Mahony, Billy wrote: > Hi Ilya, > > Thanks for the quick response. You make some good points. > > It's important to point out that local pmds are still chosen when available. > The change only operates to avoid totally non-operational/ non-polled ports. > > This is something we came across when deploying DPDK-enabled OVS in OpenStack > environments (OPNFV project). Where we had remote (both physically and > administratively) > multi-node labs already wired up and would have much preferred to have > sub-optimal > operation that a non-operational OpenStack environment. > > Some further comments below. > > Best Regards, > Billy > >> -----Original Message----- >> From: Ilya Maximets [mailto:[email protected]] >> Sent: Tuesday, February 28, 2017 11:21 AM >> To: O Mahony, Billy <[email protected]>; [email protected] >> Cc: Daniele Di Proietto <[email protected]> >> Subject: Re: [ovs-dev] dpif-netdev: Assign ports to pmds on non-local numa >> node. >> >> Hello. >> >> On 28.02.2017 13:12, Billy O'Mahony wrote: >>> From: billyom <[email protected]> >>> >>> Previously if there is no available (non-isolated) pmd on the numa >>> node for a port then the port is not polled at all. This can result in >>> a non-operational system until such time as nics are physically >>> repositioned. >> >> Why you can't just reconfigure your pmd-cpu-mask after NICs' repositioning? > [[BO'M]] The idea is to avoid having to repositioning NICs as they may be in > remote data-centers administered by other organisations. Also this can be > related > to multi-node clusters where it won't be just one NIC on one system that > needs to > be moved but several NICS/nodes affected. > > >> Maybe you can use pmd-rxq-affinity to assign port on another NUMA node? > [[BO'M]] The low-performance assignment will only occur if there is no > available > PMD on the local NUMA node. Ie if possible the normal highly performant > assignment > is made. It is only when it is a choice between lower performance and total > non-performance > that the lesser of two evils is chosen.
Maybe you can include at least one core from each node in pmd-cpu-mask? >> The main concern here is that this 'remote' port will degrade performance of >> other ports served by chosen PMD thread significantly. > [[BO'M]] That is a good point that there are second-order consequences on > other ports. > But certainly with a many cloud systems even if one port is non-operational > it means the > entire node is effectively down - for instance an OpenStack compute node with > a non-working > provider network for it's tenant VMs is useless even though the > administration and > control networks are still working. >> >> Best regards, Ilya Maximets. _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
