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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 D84A4C54FD0 for ; Thu, 23 Apr 2020 23:19:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFC7520780 for ; Thu, 23 Apr 2020 23:19:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728890AbgDWXTG (ORCPT ); Thu, 23 Apr 2020 19:19:06 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48822 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728243AbgDWXGg (ORCPT ); Thu, 23 Apr 2020 19:06:36 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkvN-0004dP-L1; Fri, 24 Apr 2020 00:06:29 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvL-00E6l1-S9; Fri, 24 Apr 2020 00:06:27 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "David S. Miller" , "Xiao Jiangfeng" , "Mao Wenan" Date: Fri, 24 Apr 2020 00:05:05 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 078/245] af_packet: set defaule value for tmo In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mao Wenan commit b43d1f9f7067c6759b1051e8ecb84e82cef569fe upstream. There is softlockup when using TPACKET_V3: ... NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms! (__irq_svc) from [] (_raw_spin_unlock_irqrestore+0x44/0x54) (_raw_spin_unlock_irqrestore) from [] (mod_timer+0x210/0x25c) (mod_timer) from [] (prb_retire_rx_blk_timer_expired+0x68/0x11c) (prb_retire_rx_blk_timer_expired) from [] (call_timer_fn+0x90/0x17c) (call_timer_fn) from [] (run_timer_softirq+0x2d4/0x2fc) (run_timer_softirq) from [] (__do_softirq+0x218/0x318) (__do_softirq) from [] (irq_exit+0x88/0xac) (irq_exit) from [] (msa_irq_exit+0x11c/0x1d4) (msa_irq_exit) from [] (handle_IPI+0x650/0x7f4) (handle_IPI) from [] (gic_handle_irq+0x108/0x118) (gic_handle_irq) from [] (__irq_usr+0x44/0x5c) ... If __ethtool_get_link_ksettings() is failed in prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies is zero and the timer expire for retire_blk_timer is turn to mod_timer(&pkc->retire_blk_timer, jiffies + 0), which will trigger cpu usage of softirq is 100%. Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Tested-by: Xiao Jiangfeng Signed-off-by: Mao Wenan Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/packet/af_packet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -608,7 +608,8 @@ static int prb_calc_retire_blk_tmo(struc msec = 1; div = speed / 1000; } - } + } else + return DEFAULT_PRB_RETIRE_TOV; mbits = (blk_size_in_bytes * 8) / (1024 * 1024);