From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBF74C28CBC for ; Thu, 30 Apr 2020 14:10:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BC2A206D9 for ; Thu, 30 Apr 2020 14:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588255808; bh=ujYPqlw40TTfE/WD3RXAUsHmr8owssXK+f6emTEkK/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Lzq2A7c+s8j6C3kbTQFntmQJ6DCEb4gQPU3tm6a1vjvSwDXllUAOXD3jFXRP5+Y/E BorskaCusiDSadoACeu0HWhiycCNfTHdExTDUY9G+P/MZ3lf+hwA9xVFh3ERLcflt6 7JsJD9NOXRTDSiYAJbSkrXAVkpC4Ce2qY2UN6AM0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728680AbgD3OKH (ORCPT ); Thu, 30 Apr 2020 10:10:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:60202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728141AbgD3Nvk (ORCPT ); Thu, 30 Apr 2020 09:51:40 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 23FFB2137B; Thu, 30 Apr 2020 13:51:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588254700; bh=ujYPqlw40TTfE/WD3RXAUsHmr8owssXK+f6emTEkK/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X5960w43BvThpyk15ga7AsK5c02kjImcGHx4/qXS6DyQNuO1ToIiizRYi8OsFWv/q cKkFsbEzX+4kMbCiyZSvOkuTJnEAn9p/8IBJwfYTSP57gc0blyx5BZ5x5nhehdFgYh 6XRoQML02cXeK7Ifjfq2e6e8z/eSryFUcPTxyV5s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Maxim Mikityanskiy , Tariq Toukan , Saeed Mahameed , Sasha Levin , netdev@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 49/79] net/mlx5e: Don't trigger IRQ multiple times on XSK wakeup to avoid WQ overruns Date: Thu, 30 Apr 2020 09:50:13 -0400 Message-Id: <20200430135043.19851-49-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200430135043.19851-1-sashal@kernel.org> References: <20200430135043.19851-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxim Mikityanskiy [ Upstream commit e7e0004abdd6f83ae4be5613b29ed396beff576c ] XSK wakeup function triggers NAPI by posting a NOP WQE to a special XSK ICOSQ. When the application floods the driver with wakeup requests by calling sendto() in a certain pattern that ends up in mlx5e_trigger_irq, the XSK ICOSQ may overflow. Multiple NOPs are not required and won't accelerate the process, so avoid posting a second NOP if there is one already on the way. This way we also avoid increasing the queue size (which might not help anyway). Fixes: db05815b36cb ("net/mlx5e: Add XSK zero-copy support") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 3 ++- drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c | 3 +++ drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 8 +++++--- drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 6 +++++- 4 files changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h index ddd2409fc8bef..5a5e6a21c6e1f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -367,6 +367,7 @@ enum { MLX5E_SQ_STATE_AM, MLX5E_SQ_STATE_TLS, MLX5E_SQ_STATE_VLAN_NEED_L2_INLINE, + MLX5E_SQ_STATE_PENDING_XSK_TX, }; struct mlx5e_sq_wqe_info { @@ -950,7 +951,7 @@ void mlx5e_page_release_dynamic(struct mlx5e_rq *rq, void mlx5e_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe); void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe); bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq); -void mlx5e_poll_ico_cq(struct mlx5e_cq *cq); +int mlx5e_poll_ico_cq(struct mlx5e_cq *cq); bool mlx5e_post_rx_mpwqes(struct mlx5e_rq *rq); void mlx5e_dealloc_rx_wqe(struct mlx5e_rq *rq, u16 ix); void mlx5e_dealloc_rx_mpwqe(struct mlx5e_rq *rq, u16 ix); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c index fe2d596cb361f..3bcdb5b2fc203 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c @@ -33,6 +33,9 @@ int mlx5e_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags) if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &c->xskicosq.state))) return 0; + if (test_and_set_bit(MLX5E_SQ_STATE_PENDING_XSK_TX, &c->xskicosq.state)) + return 0; + spin_lock(&c->xskicosq_lock); mlx5e_trigger_irq(&c->xskicosq); spin_unlock(&c->xskicosq_lock); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index 312d4692425b7..a9a96a630e4d6 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -587,7 +587,7 @@ bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq) return !!err; } -void mlx5e_poll_ico_cq(struct mlx5e_cq *cq) +int mlx5e_poll_ico_cq(struct mlx5e_cq *cq) { struct mlx5e_icosq *sq = container_of(cq, struct mlx5e_icosq, cq); struct mlx5_cqe64 *cqe; @@ -595,11 +595,11 @@ void mlx5e_poll_ico_cq(struct mlx5e_cq *cq) int i; if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state))) - return; + return 0; cqe = mlx5_cqwq_get_cqe(&cq->wq); if (likely(!cqe)) - return; + return 0; /* sq->cc must be updated only after mlx5_cqwq_update_db_record(), * otherwise a cq overrun may occur @@ -648,6 +648,8 @@ void mlx5e_poll_ico_cq(struct mlx5e_cq *cq) sq->cc = sqcc; mlx5_cqwq_update_db_record(&cq->wq); + + return i; } bool mlx5e_post_rx_mpwqes(struct mlx5e_rq *rq) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c index 800d34ed8a96c..76efa9579215c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c @@ -145,7 +145,11 @@ int mlx5e_napi_poll(struct napi_struct *napi, int budget) busy |= rq->post_wqes(rq); if (xsk_open) { - mlx5e_poll_ico_cq(&c->xskicosq.cq); + if (mlx5e_poll_ico_cq(&c->xskicosq.cq)) + /* Don't clear the flag if nothing was polled to prevent + * queueing more WQEs and overflowing XSKICOSQ. + */ + clear_bit(MLX5E_SQ_STATE_PENDING_XSK_TX, &c->xskicosq.state); busy |= mlx5e_poll_xdpsq_cq(&xsksq->cq); busy_xsk |= mlx5e_napi_xsk_post(xsksq, xskrq); } -- 2.20.1