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

王志克 wangzhike at jd.com
Wed Sep 6 09:20:22 UTC 2017


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
> 
> 



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