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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 B7399C433B4 for ; Wed, 5 May 2021 20:20:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77B74613D8 for ; Wed, 5 May 2021 20:20:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234185AbhEEUVZ (ORCPT ); Wed, 5 May 2021 16:21:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:40198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234027AbhEEUVY (ORCPT ); Wed, 5 May 2021 16:21:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E8EA7613D8; Wed, 5 May 2021 20:20:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620246028; bh=z8VC0srcx82bOMsnWf+lvtroe+Ov7KDlN6HSXpf4o60=; h=From:To:Cc:Subject:Date:From; b=ejnywMT/sM6UhDzRqDSit309HLMgyZr/LnjHzerLvv8xZiZMyu81Kbt0QBBAV06Zo SmWH0xbCSdGqNb+gkezueg5nksTC5PPbE0DwUfT8b3T0UnXdYQe5JiEeqlT92F1TEo slgWlfLoauzW69eZZT6S0IMY6RfsaqlwV9Pa/ln0AxutYQpEObTJ+3kasaxX4gQnUg zCN4JKoMmUAkuS7haE+tChPv0PbRaD81xRCwfkheazfXyBUSqGOM7eLljmCVHa16o2 MuZTeJaIMT2wz4hRtVyBg8lO9iKuQxnLHbkjHQJYnpo3g34NgZ5zBFk9YPI3bAFwLE 8stCxJGzKT6ng== From: Jakub Kicinski To: saeedm@nvidia.com, eric.dumazet@gmail.com Cc: netdev@vger.kernel.org, Jakub Kicinski Subject: [PATCH net] mlx5e: add add missing BH locking around napi_schdule() Date: Wed, 5 May 2021 13:20:26 -0700 Message-Id: <20210505202026.778635-1-kuba@kernel.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org It's not correct to call napi_schedule() in pure process context. Because we use __raise_softirq_irqoff() we require callers to be in a context which will eventually lead to softirq handling (hardirq, bh disabled, etc.). With code as is users will see: NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! Fixes: a8dd7ac12fc3 ("net/mlx5e: Generalize RQ activation") Signed-off-by: Jakub Kicinski --- We may want to patch net-next once it opens to switch from __raise_softirq_irqoff() to raise_softirq_irqoff(). The irq_count() check is probably negligable and we'd need to split the hardirq / non-hardirq paths completely to keep the current behaviour. Plus what's hardirq is murky with RT enabled.. Eric WDYT? drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index bca832cdc4cb..11e50f5b3a1e 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -889,10 +889,13 @@ int mlx5e_open_rq(struct mlx5e_params *params, struct mlx5e_rq_param *param, void mlx5e_activate_rq(struct mlx5e_rq *rq) { set_bit(MLX5E_RQ_STATE_ENABLED, &rq->state); - if (rq->icosq) + if (rq->icosq) { mlx5e_trigger_irq(rq->icosq); - else + } else { + local_bh_disable(); napi_schedule(rq->cq.napi); + local_bh_enable(); + } } void mlx5e_deactivate_rq(struct mlx5e_rq *rq) -- 2.31.1