Re: [dpdk-dev] [PATCH v2] net/mlx5: fix threshold for mbuf replenishment in MPRQ

[Raslan Darawsheh <rasland@nvidia.com>]

Hi,

> -----Original Message-----
> From: Alexander Kozyrev <akozyrev@nvidia.com>
> Sent: Tuesday, July 13, 2021 6:21 PM
> To: dev@dpdk.org
> Cc: Raslan Darawsheh <rasland@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; Slava Ovsiienko <viacheslavo@nvidia.com>;
> stable@dpdk.org
> Subject: [PATCH v2] net/mlx5: fix threshold for mbuf replenishment in MPRQ
> 
> The replenishment scheme for the vectorized MPRQ Rx burst aims
> to improve the cache locality by allocating new mbufs only when
> there are almost no mbufs left: one burst gap between allocated
> and consumed indexes.
> 
> This gap is not big enough to accommodate a corner case when we
> have a very aggressive CQE compression with multiple regular CQEs
> at the beginning and 64 zipped CQEs at the end.
> 
> Need to keep in mind this case and extend the replenishment
> threshold by MLX5_VPMD_RX_MAX_BURST (64) to avoid mbuf overflow.
> 
> Fixes: 5fc2e5c27d6 ("net/mlx5: fix mbuf overflow in vectorized MPRQ")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> ---
> 
> v2: increased the replenishment gap to MLX5_VPMD_RX_MAX_BURST
> v1:
> https://patchwork.dpdk.org/project/dpdk/patch/20210712142910.314572-1-
> akozyrev@nvidia.com/
> 
>  drivers/net/mlx5/mlx5_rxtx_vec.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh