[ICE DPDK 21.11] Latency bump at certain rate

[neeraj.sj at satyaki.co.in]

On 2022-01-07 21:48, Anantharam, Arjun wrote:
> Hi,
> 
> I believe the suggestion here would be to try the new
> "rx_low_latency=1" option enabled with DPDK 21.11:
> 
>  ·        Low Rx latency (default 0)
> 
>  vRAN workloads require low latency DPDK interface for the front haul
> interface connection to Radio. By specifying 1 for parameter
> rx_low_latency, each completed Rx descriptor can be written
> immediately to host memory and the Rx interrupt latency can be reduced
> to 2us:
> 
> -a 0000:88:00.0,rx_low_latency=1
> 
>  As a trade-off, this configuration may cause the packet processing
> performance degradation due to the PCI bandwidth limitation.
> 
> If they are using an old DPDK version, they can try to backport below
> patch
> 
> http://patchwork.dpdk.org/project/dpdk/patch/20210924093429.12068-1-alvinx.zhang@intel.com/
> 
> 
> Thanks
Hi,
We are concerned about dropping the traffic, by limiting its rate to 22 
to 24 gbps, rather than allowing complete 40gbps, a formula for cir, 
pir, ebs and cbs would be more appreciated.
Thanks.