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=-9.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A8319C3A59F for ; Fri, 30 Aug 2019 01:08:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 713CF21726 for ; Fri, 30 Aug 2019 01:08:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ck6AtN9B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727464AbfH3BIU (ORCPT ); Thu, 29 Aug 2019 21:08:20 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:39149 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726983AbfH3BIQ (ORCPT ); Thu, 29 Aug 2019 21:08:16 -0400 Received: by mail-wr1-f68.google.com with SMTP id t16so5232269wra.6 for ; Thu, 29 Aug 2019 18:08:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=8G/DolTDlEfr/BXNkcV6U3wdUVy3QAYiKCiGSbI3lQ4=; b=Ck6AtN9BIRD9SUCQsWMDZ7RkxxOPZINsxBk0k2qJK1+Xm03ZmMzgRRqjaYdzFyfYxk g8DFXP8/rLZ29Xef4Hukb9GrVePv+8D6Hyl4xzRE93q9Tgyh+WH98HYSYC5Iqnu5fBPO FJ0yPzJuO883+7UxB8bmL8nAxxD4sQ7+iE7NW02dcorwGTswpJVOFWooB/j6FhdlrRYy fac3+rdlcfx25vE5/u0P6AxBSZJMQYkpgYA+ToewxwZ3tny748k78EdMR7kDdPPrWhxe MdcBlqXWK1NxUM+h7VI94DDkcM1I4TrVH/UW6HINI8Iu4u2JQIy9vx8V6k0ny/tVqvRI YiRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=8G/DolTDlEfr/BXNkcV6U3wdUVy3QAYiKCiGSbI3lQ4=; b=Voo6AeIMxIoMygw02tgJrhLl+SQAdxJDrmrn+qhJyWja9fJ1dJ3ti9GcRRtVg9mKEE uMmv9vlvQad1MIWbRJicSe/MKn5jZIa8E7X3T0cmt63wVqoEMgHYegdssF9ivGPIEQWS d3VJbysQP+xtDFOAiFklAcuqOpKc93a8DTgDSbgb6nM0T+mJE/lnwTsZV7Tj3K9vHIMP uDcRL4rujBxz/mcoOi5kiUN4Me5ypltQH08Z8Xl4EtRXNyJJeBbASqF6qQXlv+z/f4yS O/WK65hUjN77WnVuh1orvb9DxCFlOHbaBt5DmRYk93jAClq4TW511j/pRTlKg5BYBwYR Duxg== X-Gm-Message-State: APjAAAXOt6CMGP7YTJzwQrNPxUvloVQFZ0CMECLZSZR6CtixIgCotN3D Gpd7bDHqxg4erETcjXadoYbQ7C3e0II= X-Google-Smtp-Source: APXvYqymr5BDYtSVdgIfQYThxSluhNmD4wFu1dVV0aqlUYSFox699S812F7jBQKPhLryUUuUQGIEJw== X-Received: by 2002:adf:cd11:: with SMTP id w17mr13650184wrm.297.1567127294030; Thu, 29 Aug 2019 18:08:14 -0700 (PDT) Received: from localhost.localdomain ([86.126.25.232]) by smtp.gmail.com with ESMTPSA id f13sm2813317wrq.3.2019.08.29.18.08.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Aug 2019 18:08:13 -0700 (PDT) From: Vladimir Oltean To: xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net, vinicius.gomes@intel.com, vedang.patel@intel.com, leandro.maciel.dorileo@intel.com Cc: netdev@vger.kernel.org, Vladimir Oltean Subject: [PATCH v2 net 2/3] taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte Date: Fri, 30 Aug 2019 04:07:22 +0300 Message-Id: <20190830010723.32096-3-olteanv@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190830010723.32096-1-olteanv@gmail.com> References: <20190830010723.32096-1-olteanv@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The taprio budget needs to be adapted at runtime according to interface link speed. But that handling is problematic. For one thing, installing a qdisc on an interface that doesn't have carrier is not illegal. But taprio prints the following stack trace: [ 31.851373] ------------[ cut here ]------------ [ 31.856024] WARNING: CPU: 1 PID: 207 at net/sched/sch_taprio.c:481 taprio_dequeue+0x1a8/0x2d4 [ 31.864566] taprio: dequeue() called with unknown picos per byte. [ 31.864570] Modules linked in: [ 31.873701] CPU: 1 PID: 207 Comm: tc Not tainted 5.3.0-rc5-01199-g8838fe023cd6 #1689 [ 31.881398] Hardware name: Freescale LS1021A [ 31.885661] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 31.893368] [] (show_stack) from [] (dump_stack+0xb4/0xc8) [ 31.900555] [] (dump_stack) from [] (__warn+0xe0/0xf8) [ 31.907395] [] (__warn) from [] (warn_slowpath_fmt+0x48/0x6c) [ 31.914841] [] (warn_slowpath_fmt) from [] (taprio_dequeue+0x1a8/0x2d4) [ 31.923150] [] (taprio_dequeue) from [] (__qdisc_run+0x90/0x61c) [ 31.930856] [] (__qdisc_run) from [] (net_tx_action+0x12c/0x2bc) [ 31.938560] [] (net_tx_action) from [] (__do_softirq+0x130/0x3c8) [ 31.946350] [] (__do_softirq) from [] (irq_exit+0xbc/0xd8) [ 31.953536] [] (irq_exit) from [] (__handle_domain_irq+0x60/0xb4) [ 31.961328] [] (__handle_domain_irq) from [] (gic_handle_irq+0x58/0x9c) [ 31.969638] [] (gic_handle_irq) from [] (__irq_svc+0x6c/0x90) [ 31.977076] Exception stack(0xe8167b20 to 0xe8167b68) [ 31.982100] 7b20: e9d4bd80 00000cc0 000000cf 00000000 e9d4bd80 c1f38958 00000cc0 c1f38960 [ 31.990234] 7b40: 00000001 000000cf 00000004 e9dc0800 00000000 e8167b70 c0f478ec c0f46d94 [ 31.998363] 7b60: 60070013 ffffffff [ 32.001833] [] (__irq_svc) from [] (netlink_trim+0x18/0xd8) [ 32.009104] [] (netlink_trim) from [] (netlink_broadcast_filtered+0x34/0x414) [ 32.017930] [] (netlink_broadcast_filtered) from [] (netlink_broadcast+0x20/0x28) [ 32.027102] [] (netlink_broadcast) from [] (rtnetlink_send+0x34/0x88) [ 32.035238] [] (rtnetlink_send) from [] (notify_and_destroy+0x2c/0x44) [ 32.043461] [] (notify_and_destroy) from [] (qdisc_graft+0x398/0x470) [ 32.051595] [] (qdisc_graft) from [] (tc_modify_qdisc+0x3a4/0x724) [ 32.059470] [] (tc_modify_qdisc) from [] (rtnetlink_rcv_msg+0x260/0x2ec) [ 32.067864] [] (rtnetlink_rcv_msg) from [] (netlink_rcv_skb+0xb8/0x110) [ 32.076172] [] (netlink_rcv_skb) from [] (netlink_unicast+0x1b4/0x22c) [ 32.084392] [] (netlink_unicast) from [] (netlink_sendmsg+0x33c/0x380) [ 32.092614] [] (netlink_sendmsg) from [] (sock_sendmsg+0x14/0x24) [ 32.100403] [] (sock_sendmsg) from [] (___sys_sendmsg+0x214/0x228) [ 32.108279] [] (___sys_sendmsg) from [] (__sys_sendmsg+0x50/0x8c) [ 32.116068] [] (__sys_sendmsg) from [] (ret_fast_syscall+0x0/0x54) [ 32.123938] Exception stack(0xe8167fa8 to 0xe8167ff0) [ 32.128960] 7fa0: b6fa68c8 000000f8 00000003 bea142d0 00000000 00000000 [ 32.137093] 7fc0: b6fa68c8 000000f8 0052154c 00000128 5d6468a2 00000000 00000028 00558c9c [ 32.145224] 7fe0: 00000070 bea14278 00530d64 b6e17e64 [ 32.150659] ---[ end trace 2139c9827c3e5177 ]--- This happens because the qdisc ->dequeue callback gets called. Which again is not illegal, the qdisc will dequeue even when the interface is up but doesn't have carrier (and hence SPEED_UNKNOWN), and the frames will be dropped further down the stack in dev_direct_xmit(). And, at the end of the day, for what? For calculating the initial budget of an interface which is non-operational at the moment and where frames will get dropped anyway. So if we can't figure out the link speed, default to SPEED_10 and move along. We can also remove the runtime check now. Cc: Leandro Dorileo Fixes: 7b9eba7ba0c1 ("net/sched: taprio: fix picos_per_byte miscalculation") Acked-by: Vinicius Costa Gomes Signed-off-by: Vladimir Oltean --- Changes in v2: None. net/sched/sch_taprio.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 72b5f8c1aef9..84b863e2bdbd 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -477,11 +477,6 @@ static struct sk_buff *taprio_dequeue(struct Qdisc *sch) u32 gate_mask; int i; - if (atomic64_read(&q->picos_per_byte) == -1) { - WARN_ONCE(1, "taprio: dequeue() called with unknown picos per byte."); - return NULL; - } - rcu_read_lock(); entry = rcu_dereference(q->current_entry); /* if there's no entry, it means that the schedule didn't @@ -954,12 +949,20 @@ static void taprio_set_picos_per_byte(struct net_device *dev, struct taprio_sched *q) { struct ethtool_link_ksettings ecmd; - int picos_per_byte = -1; + int speed = SPEED_10; + int picos_per_byte; + int err; + + err = __ethtool_get_link_ksettings(dev, &ecmd); + if (err < 0) + goto skip; + + if (ecmd.base.speed != SPEED_UNKNOWN) + speed = ecmd.base.speed; - if (!__ethtool_get_link_ksettings(dev, &ecmd) && - ecmd.base.speed != SPEED_UNKNOWN) - picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8, - ecmd.base.speed * 1000 * 1000); +skip: + picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8, + speed * 1000 * 1000); atomic64_set(&q->picos_per_byte, picos_per_byte); netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n", -- 2.17.1