[dpdk-users] dpdk sw schedule issue

[Van Haaren, Harry]

> -----Original Message-----
> From: users <users-bounces at dpdk.org> On Behalf Of Zhiyong Huo
> Sent: Thursday, July 30, 2020 4:05 AM
> To: users at dpdk.org
> Subject: [dpdk-users] dpdk sw schedule issue
> 
> Hi,

Hi Huo,

> We used DPDK to do high performance gateway.
> And we chose the event_sw scheduler to do the packet scheduler.
> However, there were several issues.

Would you describe your pipeline? Aka, what Eventdev Queues do you configure? (How many, and Atomic or Ordered?)

> The gateway was set with 32 cores.
> I did several test:
> 
> 
> 1.  One RX polling adapter and  one scheduler. No service core, but 32 cores to
> compete the RX adapeter/scheduler adapter.
> The performance was too low.

You mention not using a service core, does this mean that the scheduler is being run
on a thread that is also doing other work? Best performance is often achieved by giving
a dedicated thread for the scheduling work in event_sw.

> 2.  Set multi RX polling adapeters and multi schedulers.
> Get higher performance but not as expect.

The results are not as you expect - do you mean that the packet tx order is not identical to rx?
That would be an expected side-effect of using e.g. RSS to spread work to e.g. 4 NIC rx queues.

Please describe what you are trying to achieve, and what was not as expected in more detail.

> For the scheduler logic, it seemed that the DPDK has very simple scheduler logic.
> Is there any plan or suggestion about the scheduler logic?

The PMD is documented in the DPDK docs here:
https://doc.dpdk.org/guides/eventdevs/sw.html

The scheduling logic is based around Atomic and Ordered packet scheduling logic. I'm
not sure what you mean by very simple scheduler logic.


> Thanks

Regards, -Harry