Re: [dpdk-dev] [PATCH v3] ixgbe: remove vector pmd burst size restriction

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Liang, Cunming
> Sent: Tuesday, August 04, 2015 12:47 PM
> To: dev@dpdk.org
> Cc: Ananyev, Konstantin; zoltan.kiss@linaro.org; Liang, Cunming
> Subject: [PATCH v3] ixgbe: remove vector pmd burst size restriction
> 
> On receive side, the burst size now floor aligns to RTE_IXGBE_DESCS_PER_LOOP power of 2.
> According to this rule, the burst size less than 4 still won't receive anything.
> (Before this change, the burst size less than 32 can't receive anything.)
> _recv_*_pkts_vec returns no more than 32(RTE_IXGBE_RXQ_REARM_THRESH) packets.
> 
> On transmit side, the max burst size no longer bind with a constant, however it still
> require to check the cross tx_rs_thresh violation.
> 
> There's no obvious performance drop found on both recv_pkts_vec
> and recv_scattered_pkts_vec on burst size 32.
> 
> Signed-off-by: Cunming Liang <cunming.liang@intel.com>
> ---
>  v3 change:
>   - reword the init print log
> 
>  v2 change:
>   - keep max rx burst size in 32
>   - reword some comments
> 
>  drivers/net/ixgbe/ixgbe_rxtx.c     |  4 +++-
>  drivers/net/ixgbe/ixgbe_rxtx.h     |  5 ++---
>  drivers/net/ixgbe/ixgbe_rxtx_vec.c | 39 +++++++++++++++++++++-----------------
>  3 files changed, 27 insertions(+), 21 deletions(-)
> 

Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>