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 up to 4 regular CQEs
and 64 zipped CQEs at the end.
Need to keep in mind this case and extend the replenishment
threshold by MLX5_VPMD_DESCS_PER_LOOP (4) to avoid mbuf overflow.
Fixes: 5fc2e5c27d6 ("net/mlx5: fix mbuf overflow in vectorized MPRQ")
Cc: sta...@dpdk.org
Signed-off-by: Alexander Kozyrev <akozy...@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viachesl...@nvidia.com>
---
drivers/net/mlx5/mlx5_rxtx_vec.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/mlx5/mlx5_rxtx_vec.c b/drivers/net/mlx5/mlx5_rxtx_vec.c
index d5af2d91ff..e22ab665df 100644
--- a/drivers/net/mlx5/mlx5_rxtx_vec.c
+++ b/drivers/net/mlx5/mlx5_rxtx_vec.c
@@ -152,7 +152,8 @@ mlx5_rx_mprq_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq)
unsigned int i;
if (n >= rxq->rq_repl_thresh &&
- rxq->elts_ci - rxq->rq_pi <= rxq->rq_repl_thresh) {
+ rxq->elts_ci - rxq->rq_pi <=
+ (uint32_t)rxq->rq_repl_thresh + MLX5_VPMD_DESCS_PER_LOOP) {
MLX5_ASSERT(n >= MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n));
MLX5_ASSERT(MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n) >
MLX5_VPMD_DESCS_PER_LOOP);
--
2.18.2
