[ovs-dev] OVS DPDK NUMA pmd assignment question for physical port

O Mahony, Billy billy.o.mahony at intel.com
Wed Sep 6 10:35:21 UTC 2017


Hi Wang,

If you create several PMDs on the NUMA of the physical port does that have the same performance characteristic? 

/Billy



> -----Original Message-----
> From: 王志克 [mailto:wangzhike at jd.com]
> Sent: Wednesday, September 6, 2017 10:20 AM
> To: O Mahony, Billy <billy.o.mahony at intel.com>; Darrell Ball
> <dball at vmware.com>; ovs-discuss at openvswitch.org; ovs-
> dev at openvswitch.org; Kevin Traynor <ktraynor at redhat.com>
> Subject: RE: [ovs-dev] OVS DPDK NUMA pmd assignment question for
> physical port
> 
> Hi Billy,
> 
> Yes, I want to achieve better performance.
> 
> The commit "dpif-netdev: Assign ports to pmds on non-local numa node" can
> NOT meet my needs.
> 
> I do have pmd on socket 0 to poll the physical NIC which is also on socket 0.
> However, this is not enough since I also have other pmd on socket 1. I hope
> such pmds on socket 1 can together poll physical NIC. In this way, we have
> more CPU (in my case, double CPU) to poll the NIC, which results in
> performance improvement.
> 
> BR,
> Wang Zhike
> 
> -----Original Message-----
> From: O Mahony, Billy [mailto:billy.o.mahony at intel.com]
> Sent: Wednesday, September 06, 2017 5:14 PM
> To: Darrell Ball; 王志克; ovs-discuss at openvswitch.org; ovs-
> dev at openvswitch.org; Kevin Traynor
> Subject: RE: [ovs-dev] OVS DPDK NUMA pmd assignment question for
> physical port
> 
> Hi Wang,
> 
> A change was committed to head of master 2017-08-02 "dpif-netdev: Assign
> ports to pmds on non-local numa node" which if I understand your request
> correctly will do what you require.
> 
> However it is not clear to me why you are pinning rxqs to PMDs in the first
> instance. Currently if you configure at least on pmd on each numa there
> should always be a PMD available. Is the pinning for performance reasons?
> 
> Regards,
> Billy
> 
> 
> 
> > -----Original Message-----
> > From: Darrell Ball [mailto:dball at vmware.com]
> > Sent: Wednesday, September 6, 2017 8:25 AM
> > To: 王志克 <wangzhike at jd.com>; ovs-discuss at openvswitch.org; ovs-
> > dev at openvswitch.org; O Mahony, Billy <billy.o.mahony at intel.com>;
> Kevin
> > Traynor <ktraynor at redhat.com>
> > Subject: Re: [ovs-dev] OVS DPDK NUMA pmd assignment question for
> > physical port
> >
> > Adding Billy and Kevin
> >
> >
> > On 9/6/17, 12:22 AM, "Darrell Ball" <dball at vmware.com> wrote:
> >
> >
> >
> >     On 9/6/17, 12:03 AM, "王志克" <wangzhike at jd.com> wrote:
> >
> >         Hi Darrell,
> >
> >         pmd-rxq-affinity has below limitation: (so isolated pmd can
> > not be used for others, which is not my expectation. Lots of VMs come
> > and go on the fly, and manully assignment is not feasible.)
> >                   >>After that PMD threads on cores where RX queues
> > was pinned will become isolated. This means that this thread will poll
> > only pinned RX queues
> >
> >         My problem is that I have several CPUs spreading on different
> > NUMA nodes. I hope all these CPU can have chance to serve the rxq.
> > However, because the phy NIC only locates on one certain socket node,
> > non-same numa pmd/CPU would be excluded. So I am wondering whether
> we
> > can have different behavior for phy port rxq:
> >               round-robin to all PMDs even the pmd on different NUMA socket.
> >
> >         I guess this is a common case, and I believe it would improve
> > rx performance.
> >
> >
> >     [Darrell] I agree it would be a common problem and some
> > distribution would seem to make sense, maybe factoring in some
> > favoring of local numa PMDs ?
> >                     Maybe an optional config to enable ?
> >
> >
> >         Br,
> >         Wang Zhike
> >
> >



More information about the dev mailing list