From 461108de8289dbda634438e1f3a47af5a7cf45d7 Mon Sep 17 00:00:00 2001 From: Viacheslav Ovsiienko Date: Fri, 22 Jan 2021 17:12:08 +0000 Subject: [PATCH] net/mlx5: optimize inline mbuf freeing The mlx5 PMD supports packet data inlining by pushing data to the transmit descriptor. If packet is short enough and all data are inline, the mbuf is not needed for data send anymore and can be freed. The mbuf free was performed in the most inner loop building the transmit descriptors. This patch postpones the mbuf free transaction to the tx_burst routine exit, optimizing the loop and allowing the bulk freeing for the multiple mbufs in single pool API call. Signed-off-by: Viacheslav Ovsiienko Acked-by: Matan Azrad --- drivers/net/mlx5/mlx5_rxtx.c | 38 ++++++++++++++++++++++++++++++++---- drivers/net/mlx5/mlx5_rxtx.h | 1 + 2 files changed, 35 insertions(+), 4 deletions(-) diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c index 3497765ac8..97912dd70a 100644 --- a/drivers/net/mlx5/mlx5_rxtx.c +++ b/drivers/net/mlx5/mlx5_rxtx.c @@ -1990,6 +1990,17 @@ mlx5_tx_free_mbuf(struct rte_mbuf **__rte_restrict pkts, } } } +/* + * No inline version to free buffers for optimal call + * on the tx_burst completion. + */ +static __rte_noinline void +__mlx5_tx_free_mbuf(struct rte_mbuf **__rte_restrict pkts, + unsigned int pkts_n, + unsigned int olx __rte_unused) +{ + mlx5_tx_free_mbuf(pkts, pkts_n, olx); +} /** * Free the mbuf from the elts ring buffer till new tail. @@ -4408,10 +4419,25 @@ mlx5_tx_burst_empw_inline(struct mlx5_txq_data *__rte_restrict txq, MLX5_ASSERT(room >= tlen); room -= tlen; /* - * Packet data are completely inlined, - * free the packet immediately. + * Packet data are completely inline, + * we can try to free the packet. + */ + if (likely(loc->pkts_sent == loc->mbuf_free)) { + /* + * All the packets from the burst beginning + * are inline, we can free mbufs directly + * from the origin array on tx_burst exit(). + */ + loc->mbuf_free++; + goto next_mbuf; + } + /* + * In order no to call rte_pktmbuf_free_seg() here, + * in the most inner loop (that might be very + * expensive) we just save the mbuf in elts. */ - rte_pktmbuf_free_seg(loc->mbuf); + txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf; + loc->elts_free--; goto next_mbuf; pointer_empw: /* @@ -4433,6 +4459,7 @@ pointer_empw: mlx5_tx_dseg_ptr(txq, loc, dseg, dptr, dlen, olx); /* We have to store mbuf in elts.*/ txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf; + loc->elts_free--; room -= MLX5_WQE_DSEG_SIZE; /* Ring buffer wraparound is checked at the loop end.*/ ++dseg; @@ -4442,7 +4469,6 @@ next_mbuf: slen += dlen; #endif loc->pkts_sent++; - loc->elts_free--; pkts_n--; if (unlikely(!pkts_n || !loc->elts_free)) { /* @@ -4892,6 +4918,8 @@ mlx5_tx_burst_tmpl(struct mlx5_txq_data *__rte_restrict txq, MLX5_ASSERT(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi)); if (unlikely(!pkts_n)) return 0; + if (MLX5_TXOFF_CONFIG(INLINE)) + loc.mbuf_free = 0; loc.pkts_sent = 0; loc.pkts_copy = 0; loc.wqe_last = NULL; @@ -5155,6 +5183,8 @@ burst_exit: /* Increment sent packets counter. */ txq->stats.opackets += loc.pkts_sent; #endif + if (MLX5_TXOFF_CONFIG(INLINE) && loc.mbuf_free) + __mlx5_tx_free_mbuf(pkts, loc.mbuf_free, olx); return loc.pkts_sent; } diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h index 7756ed34c3..9dac408530 100644 --- a/drivers/net/mlx5/mlx5_rxtx.h +++ b/drivers/net/mlx5/mlx5_rxtx.h @@ -209,6 +209,7 @@ struct mlx5_txq_local { uint16_t wqe_free; /* available wqe remain. */ uint16_t mbuf_off; /* data offset in current mbuf. */ uint16_t mbuf_nseg; /* number of remaining mbuf. */ + uint16_t mbuf_free; /* number of inline mbufs to free. */ }; /* TX queue descriptor. */ -- 2.20.1