From mboxrd@z Thu Jan 1 00:00:00 1970 From: Saeed Mahameed Subject: [net-next 07/17] net/mlx5e: Early-return on empty completion queues Date: Sun, 3 Sep 2017 07:21:07 +0300 Message-ID: <20170903042117.28923-8-saeedm@mellanox.com> References: <20170903042117.28923-1-saeedm@mellanox.com> Cc: netdev@vger.kernel.org, kernel-team@fb.com, Tariq Toukan , Saeed Mahameed To: "David S. Miller" Return-path: Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:60018 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751082AbdICEWL (ORCPT ); Sun, 3 Sep 2017 00:22:11 -0400 In-Reply-To: <20170903042117.28923-1-saeedm@mellanox.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Tariq Toukan NAPI context handles different kinds of completion queues (RX, TX, and others). Hence, upon a poll trial, some of them might be empty. Here we early-return upon empty completion queues, as well as full rx buffer, and save unnecessary logic and memory barriers. Signed-off-by: Tariq Toukan Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 40 ++++++++++++++----------- drivers/net/ethernet/mellanox/mlx5/core/en_tx.c | 16 +++++----- 2 files changed, 32 insertions(+), 24 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index 8af6577b7501..ab1213a3615e 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -459,16 +459,19 @@ void mlx5e_dealloc_rx_mpwqe(struct mlx5e_rq *rq, u16 ix) bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq) { struct mlx5_wq_ll *wq = &rq->wq; + int err; if (unlikely(!test_bit(MLX5E_RQ_STATE_ENABLED, &rq->state))) return false; + if (mlx5_wq_ll_is_full(wq)) + return false; + if (test_bit(MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS, &rq->state)) return true; - while (!mlx5_wq_ll_is_full(wq)) { + do { struct mlx5e_rx_wqe *wqe = mlx5_wq_ll_get_wqe(wq, wq->head); - int err; err = rq->alloc_wqe(rq, wqe, wq->head); if (err == -EBUSY) @@ -479,14 +482,14 @@ bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq) } mlx5_wq_ll_push(wq, be16_to_cpu(wqe->next.next_wqe_index)); - } + } while (!mlx5_wq_ll_is_full(wq)); /* ensure wqes are visible to device before updating doorbell record */ dma_wmb(); mlx5_wq_ll_update_db_record(wq); - return !mlx5_wq_ll_is_full(wq); + return !!err; } static void mlx5e_lro_update_hdr(struct sk_buff *skb, struct mlx5_cqe64 *cqe, @@ -981,7 +984,8 @@ void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe) int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) { struct mlx5e_rq *rq = container_of(cq, struct mlx5e_rq, cq); - struct mlx5e_xdpsq *xdpsq = &rq->xdpsq; + struct mlx5e_xdpsq *xdpsq; + struct mlx5_cqe64 *cqe; int work_done = 0; if (unlikely(!test_bit(MLX5E_RQ_STATE_ENABLED, &rq->state))) @@ -990,12 +994,13 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) if (cq->decmprs_left) work_done += mlx5e_decompress_cqes_cont(rq, cq, 0, budget); - for (; work_done < budget; work_done++) { - struct mlx5_cqe64 *cqe = mlx5_cqwq_get_cqe(&cq->wq); + cqe = mlx5_cqwq_get_cqe(&cq->wq); + if (!cqe) + return 0; - if (!cqe) - break; + xdpsq = &rq->xdpsq; + do { if (mlx5_get_cqe_format(cqe) == MLX5_COMPRESSED) { work_done += mlx5e_decompress_cqes_start(rq, cq, @@ -1006,7 +1011,7 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) mlx5_cqwq_pop(&cq->wq); rq->handle_rx_cqe(rq, cqe); - } + } while ((++work_done < budget) && (cqe = mlx5_cqwq_get_cqe(&cq->wq))); if (xdpsq->db.doorbell) { mlx5e_xmit_xdp_doorbell(xdpsq); @@ -1024,6 +1029,7 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq) { struct mlx5e_xdpsq *sq; + struct mlx5_cqe64 *cqe; struct mlx5e_rq *rq; u16 sqcc; int i; @@ -1033,6 +1039,10 @@ bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq) if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state))) return false; + cqe = mlx5_cqwq_get_cqe(&cq->wq); + if (!cqe) + return false; + rq = container_of(sq, struct mlx5e_rq, xdpsq); /* sq->cc must be updated only after mlx5_cqwq_update_db_record(), @@ -1040,15 +1050,11 @@ bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq) */ sqcc = sq->cc; - for (i = 0; i < MLX5E_TX_CQ_POLL_BUDGET; i++) { - struct mlx5_cqe64 *cqe; + i = 0; + do { u16 wqe_counter; bool last_wqe; - cqe = mlx5_cqwq_get_cqe(&cq->wq); - if (!cqe) - break; - mlx5_cqwq_pop(&cq->wq); wqe_counter = be16_to_cpu(cqe->wqe_counter); @@ -1066,7 +1072,7 @@ bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq) /* Recycle RX page */ mlx5e_page_release(rq, di, true); } while (!last_wqe); - } + } while ((++i < MLX5E_TX_CQ_POLL_BUDGET) && (cqe = mlx5_cqwq_get_cqe(&cq->wq))); mlx5_cqwq_update_db_record(&cq->wq); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c index 31353e5c3c78..80d2121643ee 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c @@ -394,6 +394,7 @@ netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev) bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget) { struct mlx5e_txqsq *sq; + struct mlx5_cqe64 *cqe; u32 dma_fifo_cc; u32 nbytes; u16 npkts; @@ -405,6 +406,10 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget) if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state))) return false; + cqe = mlx5_cqwq_get_cqe(&cq->wq); + if (!cqe) + return false; + npkts = 0; nbytes = 0; @@ -416,15 +421,11 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget) /* avoid dirtying sq cache line every cqe */ dma_fifo_cc = sq->dma_fifo_cc; - for (i = 0; i < MLX5E_TX_CQ_POLL_BUDGET; i++) { - struct mlx5_cqe64 *cqe; + i = 0; + do { u16 wqe_counter; bool last_wqe; - cqe = mlx5_cqwq_get_cqe(&cq->wq); - if (!cqe) - break; - mlx5_cqwq_pop(&cq->wq); wqe_counter = be16_to_cpu(cqe->wqe_counter); @@ -467,7 +468,8 @@ bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget) sqcc += wi->num_wqebbs; napi_consume_skb(skb, napi_budget); } while (!last_wqe); - } + + } while ((++i < MLX5E_TX_CQ_POLL_BUDGET) && (cqe = mlx5_cqwq_get_cqe(&cq->wq))); mlx5_cqwq_update_db_record(&cq->wq); -- 2.13.0