Re: [dpdk-users] what is the average latency you get for io forwarding from dpdk?

[Pavel Shirshov <pavel.shirshov@gmail.com>]

Hi Maruko,

I'd say that dpdk is not about minimal latency, but about maximum
flexibility and development speed.
dpdk is not ASIC.
ASIC, FPGA, anything not soft related will give you better latency time.
So if you are looking for minimal and predictable latency I suspect
you need to think about other options.


On Tue, Jan 17, 2017 at 12:28 AM, Marco Kwok <maruko.kwok@gmail.com> wrote:
> Hello all,
>
> I wonder if anyone could get a relative low latency from dpdk on 1gb link.
>
> When using testpmd, an packet of 150 bytes is sent, packet is received by
> the port and loopback to the sender.
> I usually could get 50us for io forward. Sometime it can be as fast as 3us.
> However it is too slow to be used for switching application.
>
> My test platform is on a intel NUC NUC5I5RYH, which has i5 5250U 1.6GHz,
> 16GB DDR3 and i218-V network chip. dpdk 16.07.2
>
>
> I have done the following things try to get a better latency with no luck:
> -setup 1G hugepages
> -disable cpu frequency scaling to make sure cpu runs at max speed of 2.7GHz
> -isolate a cpu core from kernel task scheduler by isolcpus
> -setting the burst size of testpmd to 1
>
> Guys, I really want your input. I don't need high throughput but low
> latency. Does anyone of you have been able to achieve a lower latency with
> dpdk? I don't see the advantage I have taken from dpdk now.
>
> Best,
> Mark