RE: [PATCH 0/2] Add logic to IAVF to count continuous DD bits for Arm

[Kathleen Capella <Kathleen.Capella@arm.com>]

The failure in ci/iol-x86_64-unit-testing on this patch seems to be unrelated to the patch.

> -----Original Message-----
> From: Kathleen Capella <kathleen.capella@arm.com>
> Sent: Friday, February 4, 2022 6:26 PM
> Cc: dev@dpdk.org; nd <nd@arm.com>; Dharmik Thakkar
> <Dharmik.Thakkar@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; Kathleen Capella
> <Kathleen.Capella@arm.com>
> Subject: [PATCH 0/2] Add logic to IAVF to count continuous DD bits for Arm
> 
> This patchset introduces a fix for Arm platforms to the IAVF driver that was
> added to the i40e driver in a previous patchset [1].
> 
> The driver determines which descriptors in the HW ring reference packets
> that are ready to be received by counting those descriptors whose DD bit is
> set to 1. On Arm, the reading of descriptors can be reordered. The CPU may
> be reading descriptors as the NIC is updating them. Tt is possbile that the DD
> bit for a descriptor earlier in the queue is read as not set while the DD bit for
> a descriptor later in the queue is read as set. This patchset ensures only
> contiguous DD bits set to 1 are counted.
> 
> The first patch in this series adds this logic to the bulk Rx path.
> The second patch adds this same logic to the function which reads flexible Rx
> descriptors.
> 
> No performance drop was observed when running l3fwd on N1SDP with a
> single core.
> 
> [1]
> https://patches.dpdk.org/project/dpdk/patch/20210706065404.25137-2-
> joyce.kong@arm.com/
> 
> Kathleen Capella (2):
>   net/iavf: count continuous DD bits for Arm
>   net/iavf: count continuous DD bits for Arm in flex Rx
> 
>  drivers/net/iavf/iavf_rxtx.c | 52 ++++++++++++++++++++++++++++++------
>  1 file changed, 44 insertions(+), 8 deletions(-)
> 
> --
> 2.17.1