From patchwork Sun Aug 4 13:55:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slava Ovsiienko X-Patchwork-Id: 57410 X-Patchwork-Delegate: rasland@nvidia.com Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 523651BE73; Sun, 4 Aug 2019 15:55:33 +0200 (CEST) Received: from mellanox.co.il (mail-il-dmz.mellanox.com [193.47.165.129]) by dpdk.org (Postfix) with ESMTP id 727B11BE6B for ; Sun, 4 Aug 2019 15:55:32 +0200 (CEST) Received: from Internal Mail-Server by MTLPINE2 (envelope-from viacheslavo@mellanox.com) with ESMTPS (AES256-SHA encrypted); 4 Aug 2019 16:55:31 +0300 Received: from pegasus12.mtr.labs.mlnx (pegasus12.mtr.labs.mlnx [10.210.17.40]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x74DtVmr002787; Sun, 4 Aug 2019 16:55:31 +0300 Received: from pegasus12.mtr.labs.mlnx (localhost [127.0.0.1]) by pegasus12.mtr.labs.mlnx (8.14.7/8.14.7) with ESMTP id x74DtV7q031494; Sun, 4 Aug 2019 13:55:31 GMT Received: (from viacheslavo@localhost) by pegasus12.mtr.labs.mlnx (8.14.7/8.14.7/Submit) id x74DtU50031493; Sun, 4 Aug 2019 13:55:30 GMT X-Authentication-Warning: pegasus12.mtr.labs.mlnx: viacheslavo set sender to viacheslavo@mellanox.com using -f From: Viacheslav Ovsiienko To: dev@dpdk.org Cc: yskoh@mellanox.com, shahafs@mellanox.com Date: Sun, 4 Aug 2019 13:55:27 +0000 Message-Id: <1564926927-31450-1-git-send-email-viacheslavo@mellanox.com> X-Mailer: git-send-email 1.8.3.1 Subject: [dpdk-dev] [PATCH] net/mlx5: fix completion queue overflow for large bursts X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" There is the limit on completion descriptor fetch to improve latency. If burst size is large there might be not enough resources freed in completion processing. This fix reiterates sending loop and allows multiple completion descriptor fetch and processing. Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template") Signed-off-by: Viacheslav Ovsiienko Acked-by: Matan Azrad --- drivers/net/mlx5/mlx5_rxtx.c | 29 ++++++++++++++++++++--------- drivers/net/mlx5/mlx5_rxtx.h | 1 + 2 files changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c index 308133b..4b26562 100644 --- a/drivers/net/mlx5/mlx5_rxtx.c +++ b/drivers/net/mlx5/mlx5_rxtx.c @@ -4522,6 +4522,14 @@ enum mlx5_txcmp_code { assert(txq->elts_s >= (uint16_t)(txq->elts_head - txq->elts_tail)); assert(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi)); + if (unlikely(!pkts_n)) + return 0; + loc.pkts_sent = 0; + loc.pkts_copy = 0; + loc.wqe_last = NULL; + +send_loop: + loc.pkts_loop = loc.pkts_sent; /* * Check if there are some CQEs, if any: * - process an encountered errors @@ -4529,9 +4537,7 @@ enum mlx5_txcmp_code { * - free related mbufs * - doorbell the NIC about processed CQEs */ - if (unlikely(!pkts_n)) - return 0; - rte_prefetch0(*pkts); + rte_prefetch0(*(pkts + loc.pkts_sent)); mlx5_tx_handle_completion(txq, olx); /* * Calculate the number of available resources - elts and WQEs. @@ -4548,10 +4554,7 @@ enum mlx5_txcmp_code { loc.wqe_free = txq->wqe_s - (uint16_t)(txq->wqe_ci - txq->wqe_pi); if (unlikely(!loc.elts_free || !loc.wqe_free)) - return 0; - loc.pkts_sent = 0; - loc.pkts_copy = 0; - loc.wqe_last = NULL; + return loc.pkts_sent; for (;;) { /* * Fetch the packet from array. Usually this is @@ -4717,8 +4720,8 @@ enum mlx5_txcmp_code { */ assert(MLX5_TXOFF_CONFIG(INLINE) || loc.pkts_sent >= loc.pkts_copy); /* Take a shortcut if nothing is sent. */ - if (unlikely(loc.pkts_sent == 0)) - return 0; + if (unlikely(loc.pkts_sent == loc.pkts_loop)) + return loc.pkts_sent; /* * Ring QP doorbell immediately after WQE building completion * to improve latencies. The pure software related data treatment @@ -4747,6 +4750,14 @@ enum mlx5_txcmp_code { #endif assert(txq->elts_s >= (uint16_t)(txq->elts_head - txq->elts_tail)); assert(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi)); + if (pkts_n > loc.pkts_sent) { + /* + * If burst size is large there might be no enough CQE + * fetched from completion queue and no enough resources + * freed to send all the packets. + */ + goto send_loop; + } return loc.pkts_sent; } diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h index aaa02a2..bad9e9c 100644 --- a/drivers/net/mlx5/mlx5_rxtx.h +++ b/drivers/net/mlx5/mlx5_rxtx.h @@ -239,6 +239,7 @@ struct mlx5_txq_local { struct rte_mbuf *mbuf; /* first mbuf to process. */ uint16_t pkts_copy; /* packets copied to elts. */ uint16_t pkts_sent; /* packets sent. */ + uint16_t pkts_loop; /* packets sent on loop entry. */ uint16_t elts_free; /* available elts remain. */ uint16_t wqe_free; /* available wqe remain. */ uint16_t mbuf_off; /* data offset in current mbuf. */