From 5fc2e5c27d69bcebb352d17603a1d3ca2628f17b Mon Sep 17 00:00:00 2001 From: Alexander Kozyrev Date: Sat, 21 Nov 2020 03:42:39 +0000 Subject: [PATCH] net/mlx5: fix mbuf overflow in vectorized MPRQ Changing the allocation scheme to improve mbufs locality caused mbufs overrun in some cases. Revert the previous replenish logic back. Calculate a number of unused mbufs and replenish max this number of mbufs. Mark the last 4 mbufs as fake mbufs to prevent overflowing into consumed mbufs in the future. Keep the consumed index and the produced index 4 mbufs apart for this purpose. Replenish some mbufs only in case the consumed index is within the replenish threshold of the produced index in order to retain the cache locality for the vectorized MPRQ routine. Fixes: 5c68764377 ("net/mlx5: improve vectorized MPRQ descriptors locality") Signed-off-by: Alexander Kozyrev Acked-by: Viacheslav Ovsiienko --- drivers/net/mlx5/mlx5_rxtx_vec.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/net/mlx5/mlx5_rxtx_vec.c b/drivers/net/mlx5/mlx5_rxtx_vec.c index 68c51dce31..028e0f6121 100644 --- a/drivers/net/mlx5/mlx5_rxtx_vec.c +++ b/drivers/net/mlx5/mlx5_rxtx_vec.c @@ -145,22 +145,29 @@ mlx5_rx_mprq_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq) const uint32_t strd_n = 1 << rxq->strd_num_n; const uint32_t elts_n = wqe_n * strd_n; const uint32_t wqe_mask = elts_n - 1; - uint32_t n = rxq->elts_ci - rxq->rq_pi; + uint32_t n = elts_n - (rxq->elts_ci - rxq->rq_pi); uint32_t elts_idx = rxq->elts_ci & wqe_mask; struct rte_mbuf **elts = &(*rxq->elts)[elts_idx]; + unsigned int i; - if (n <= rxq->rq_repl_thresh) { - MLX5_ASSERT(n + MLX5_VPMD_RX_MAX_BURST >= - MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n)); + if (n >= rxq->rq_repl_thresh && + rxq->elts_ci - rxq->rq_pi <= rxq->rq_repl_thresh) { + MLX5_ASSERT(n >= MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n)); MLX5_ASSERT(MLX5_VPMD_RXQ_RPLNSH_THRESH(elts_n) > MLX5_VPMD_DESCS_PER_LOOP); /* Not to cross queue end. */ - n = RTE_MIN(n + MLX5_VPMD_RX_MAX_BURST, elts_n - elts_idx); + n = RTE_MIN(n - MLX5_VPMD_DESCS_PER_LOOP, elts_n - elts_idx); + /* Limit replenish number to threshold value. */ + n = RTE_MIN(n, rxq->rq_repl_thresh); if (rte_mempool_get_bulk(rxq->mp, (void *)elts, n) < 0) { rxq->stats.rx_nombuf += n; return; } rxq->elts_ci += n; + /* Prevent overflowing into consumed mbufs. */ + elts_idx = rxq->elts_ci & wqe_mask; + for (i = 0; i < MLX5_VPMD_DESCS_PER_LOOP; ++i) + (*rxq->elts)[elts_idx + i] = &rxq->fake_mbuf; } } -- 2.20.1