This adds a limitation explanation on RSS queue usage for MLX4 pmd. MLX4 pmd requires a power of two queues to do RSS but, the user can still open more queues which can be utilized through flow API.
Signed-off-by: Raslan Darawsheh <rasl...@nvidia.com> --- doc/guides/nics/mlx4.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst index c6279f51d0..f59e52a671 100644 --- a/doc/guides/nics/mlx4.rst +++ b/doc/guides/nics/mlx4.rst @@ -145,6 +145,18 @@ Limitations - TSO (Transmit Segmentation Offload) is supported in OFED version 4.4 and above. +- RSS only works on power of two number of queues. +- The user can open none power of two queues, but the PMD will round down + to the highest power of two queues by default for RSS. + Other queues can be utilized through flow API. + example:: + ./dpdk-testpmd -a 08:00.0 -- -i --rxq 12 --txq 12 --rss-ip + + The first 8 queues will be used by default for RSS over IP. + The rest of the queues can be utilized through rte flow like the following:: + flow create 0 ingress pattern eth / ipv4 / tcp / end actions rss queues 8 9 10 11 end / end + + Prerequisites ------------- -- 2.25.1
