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SRIOV gives you the maximum performance, without any SW features
(security group, L3 routing, etc.), because it bypasses SW.
DPDK gives you less performance, with all SW features.

Depend on the use case, max perf and SW features, you will need
to make a decision.


Tony
> -----Original Message-----
> From: Laurent Dumont <laurentfdumont at gmail.com>
> Sent: Sunday, November 8, 2020 9:04 AM
> To: Satish Patel <satish.txt at gmail.com>
> Cc: OpenStack Discuss <openstack-discuss at lists.openstack.org>
> Subject: Re: openvswitch+dpdk 100% cpu usage of ovs-vswitchd
> 
> I have limited hands-on experience with both but they don't serve the
> same purpose/have the same implementation. You use SRIOV to allow
> Tenants to access the NIC cards directly and bypass any inherent linux-
> vr/OVS performance limitations. This is key for NFV workloads which are
> expecting large amount of PPS + low latency (because they are often just
> virtualized bare-metal products with one real cloud-
> readiness/architecture ;) ) - This means that a Tenant with an SRIOV
> port can use DPDK + access the NIC through the VF which means (in theory)
> a better performance than OVS+DPDK.
> 
> You use ovs-dpdk to increase the performance of OVS based flows (so
> provider networks + vxlan based internal-tenant networks).
> 
> On Sun, Nov 8, 2020 at 11:13 AM Satish Patel <satish.txt at gmail.com
> <mailto:satish.txt at gmail.com> > wrote:
> 
> 
> 	 Thanks. Just curious then why people directly go for SR-IOV
> 	implementation where they get better performance + they can use the
> 	same CPU more also. What are the measure advantages or features
> 	attracting the community to go with DPDK over SR-IOV?
> 
> 	On Sun, Nov 8, 2020 at 10:50 AM Laurent Dumont
> <laurentfdumont at gmail.com <mailto:laurentfdumont at gmail.com> > wrote:
> 	>
> 	> As far as I know, DPDK enabled cores will show 100% usage at all
> times.
> 	>
> 	> On Sun, Nov 8, 2020 at 9:39 AM Satish Patel <satish.txt at gmail.com
> <mailto:satish.txt at gmail.com> > wrote:
> 	>>
> 	>> Folks,
> 	>>
> 	>> Recently i have added come compute nodes in cloud supporting
> 	>> openvswitch-dpdk for performance. I am seeing all my PMD cpu
> cores are
> 	>> 100% cpu usage on linux top command. It is normal behavior from
> first
> 	>> looks. It's very scary to see 400% cpu usage on top. Can someone
> 	>> confirm before I assume it's normal and what we can do to reduce
> it if
> 	>> it's too high?
> 	>>
>