RE: [PATCH] net/iavf: remove extra copy step in Rx bulk path

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Kathleen Capella <kathleen.capella@arm.com>
> Sent: Friday, March 25, 2022 6:12 AM
> To: Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei <beilei.xing@intel.com>
> Cc: dev@dpdk.org; nd@arm.com; honnappa.nagarahalli@arm.com;
> dharmik.thakkar@arm.com; Kathleen Capella <kathleen.capella@arm.com>
> Subject: [PATCH] net/iavf: remove extra copy step in Rx bulk path
> 
> In the Rx bulk path, packets which are taken from the HW ring, are first
> copied to the stage data structure and then later copied from the stage to the
> rx_pkts array. For the number of packets requested immediately by the
> receiving function, this two-step process adds extra overhead that is not
> necessary.
> 
> Instead, put requested number of packets directly into the rx_pkts array and
> only stage excess packets. On N1SDP with 1 core/port, l3fwd saw up to 4%
> performance improvement. On x86, no difference in performance was
> observed.
> 
> Signed-off-by: Kathleen Capella <kathleen.capella@arm.com>
> Suggested-by: Dharmik Thakkar <dharmik.thakkar@arm.com>

Acked-by: Qi Zhang <qi.z.zhang@intel.com>

Applied to dpdk-next-net-intel.

Thanks
Qi