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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DB175C5ACC6 for ; Tue, 16 Oct 2018 17:18:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A33BA21477 for ; Tue, 16 Oct 2018 17:18:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="m4rcLRTA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A33BA21477 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730156AbeJQBKD (ORCPT ); Tue, 16 Oct 2018 21:10:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:54872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728680AbeJQBKC (ORCPT ); Tue, 16 Oct 2018 21:10:02 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 67B212147C; Tue, 16 Oct 2018 17:18:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539710318; bh=ZCKehb65ezTLMocdUmzoC2q5LuXD6iSu9Up1di8tmbM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m4rcLRTALC5sz1T51+UifB4ZC+R04CUM9gxEfbkFCsa/o3PO/ViqWKLkSBE/MCRDu yiDcfALGXxtSfCqzs4JgeBQbdvnDYuEQQ4m7LMZo/pVeOTBg9gZHKq4uWV6/LAiCBr IbYk57soBUT5UWdevt2tL6jZqhzgUKc+QCXE5yjE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jakub Kicinski , Simon Horman , Pieter Jansen van Vuuren , "David S. Miller" Subject: [PATCH 4.14 034/109] nfp: avoid soft lockups under control message storm Date: Tue, 16 Oct 2018 19:05:02 +0200 Message-Id: <20181016170526.889486892@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181016170524.530541524@linuxfoundation.org> References: <20181016170524.530541524@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Kicinski [ Upstream commit ff58e2df62ce29d0552278c290ae494b30fe0c6f ] When FW floods the driver with control messages try to exit the cmsg processing loop every now and then to avoid soft lockups. Cmsg processing is generally very lightweight so 512 seems like a reasonable budget, which should not be exceeded under normal conditions. Fixes: 77ece8d5f196 ("nfp: add control vNIC datapath") Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Tested-by: Pieter Jansen van Vuuren Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -2058,14 +2058,17 @@ nfp_ctrl_rx_one(struct nfp_net *nn, stru return true; } -static void nfp_ctrl_rx(struct nfp_net_r_vector *r_vec) +static bool nfp_ctrl_rx(struct nfp_net_r_vector *r_vec) { struct nfp_net_rx_ring *rx_ring = r_vec->rx_ring; struct nfp_net *nn = r_vec->nfp_net; struct nfp_net_dp *dp = &nn->dp; + unsigned int budget = 512; - while (nfp_ctrl_rx_one(nn, dp, r_vec, rx_ring)) + while (nfp_ctrl_rx_one(nn, dp, r_vec, rx_ring) && budget--) continue; + + return budget; } static void nfp_ctrl_poll(unsigned long arg) @@ -2077,9 +2080,13 @@ static void nfp_ctrl_poll(unsigned long __nfp_ctrl_tx_queued(r_vec); spin_unlock_bh(&r_vec->lock); - nfp_ctrl_rx(r_vec); - - nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry); + if (nfp_ctrl_rx(r_vec)) { + nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry); + } else { + tasklet_schedule(&r_vec->tasklet); + nn_dp_warn(&r_vec->nfp_net->dp, + "control message budget exceeded!\n"); + } } /* Setup and Configuration