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=-3.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3E03CC433DF for ; Tue, 13 Oct 2020 03:00:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C811120757 for ; Tue, 13 Oct 2020 03:00:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="LF/Rpxfo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728474AbgJMDAb (ORCPT ); Mon, 12 Oct 2020 23:00:31 -0400 Received: from mout.gmx.net ([212.227.17.21]:45189 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727888AbgJMDAa (ORCPT ); Mon, 12 Oct 2020 23:00:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1602558019; bh=o8Bk9I/Jh6aJVgAJo/80Zhfeu3fuUmx/2h4DjtjCY6g=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date:In-Reply-To:References; b=LF/RpxfoNlbrTop/AJenkq7HzKZRTIJs/Cp/i5OBOMrgLKm9FsMnJ7JqbYafrIbBn KUAq0ltADwD5xCUDzbMcp2R9kBiR/baDqcNs2MVye7JotNu+6gxv5M3kxmE185DdW3 +emHjnsuIm8Bwgy+WhpA3JvOxl9tegMMtyPvXgQA= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from homer.simpson.net ([185.191.217.248]) by mail.gmx.com (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MG9kC-1kgTuB2hNE-00GZNL; Tue, 13 Oct 2020 05:00:19 +0200 Message-ID: Subject: Re: [RT] 5.9-rt14 softirq_ctrl.lock vs listening_hash[i].lock lockdep splat From: Mike Galbraith To: Sebastian Andrzej Siewior Cc: tglx@linutronix.de, linux-rt-users@vger.kernel.org, lkml Date: Tue, 13 Oct 2020 05:00:18 +0200 In-Reply-To: <90459a197f5dad3b17ff8c484cc315c9b054f5c0.camel@gmx.de> References: <12d6f9879a97cd56c09fb53dee343cbb14f7f1f7.camel@gmx.de> <20201012164553.kkk7aaeyb3y4wvyh@linutronix.de> <90459a197f5dad3b17ff8c484cc315c9b054f5c0.camel@gmx.de> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:htRTdghFIMIyb/LlpergTCR5rEc97PgFaxXREJ69kYtQhoNB3uM pcCnHaOq+t5TPk6Yv9cX03UX2XvzvXLscV5r9FCna3TTkUZkpJWOzuJMOgdRxLthLCFL/13 wHKRf5Q6SnHFXJH8RSK6Pfcd6Reps6gMoUGbd0FaLXpgJqWqEbQ/iO1h43rhHKBplCkYhAJ 6CM/ibWQOSwOIhBV+PgUw== X-UI-Out-Filterresults: notjunk:1;V03:K0:1oV34MMKk2M=:jDo6Z9S8s+9IOfcgrK++N1 IQSjENN5bJPcpVbgtel/rKaXnculzhv8QRnzmdQ8Wbv7YXZNNhxP/D+Xs09gp/mKV4wil/pjD JKQ/03nOSu1uhKogLtfgNqOiBa1P83sEDbvTX/dI8wa8MXJRysEJAkEq0BXVIfMj/4vNNBEJh lD9YQDlvSnxNkFDp2SDJmMOzjjNCk43CkkwwQkhOFZpOckqy6dxq4o46LkZNGaEz6mAVgSXJB QYkBqerwi4z2qqavE7X8j/J3YOrg33CQtLURgFqfMG0CHeF++0VAFXUmh2R2bdstBcTUAFUU6 pDeW8OUdj/LhclKaQmtqiN2AXZJ8OgAk/txxc2NEAyU0qyW5ofi0hnQfhmdxufwA5GfCAf+ve Wd+HjmjL/XXWMKk7MubOfdEOVenSuwYxdZWTU/rd6OmjJELmR4OLZt0DrPwFugjk8xoAgTJlj ZqFIUmbmego1Vxj71/UAXLiJKrb7LrYUVipsupGkG0UXDZF7hbTvK/AEVsrijpUyTkk2CKHW/ Y1O6oE63Dl0p4JRWwPc10jrpii1I527sqwVwtLN2dpVHREqP79ztwOxtEIZxTrfasd+x4fiic luxhkmFjEV88SWociZc7EKGZQCh04aRQb7fb4+qfgdwFCTL8fJKDvaglWa3dpwVfX2zzyGeXj /YnGDDTmLOZN09ytkRiKoiIPhppxgOkb4Ec2kTjXM8Bgq/PeLmEbttTkB1gpFEmPVT76D7zhf BbSHxwt7rrFLWX5vMS0CLgnUF1ZZ+HUI4gWmWK9Abre5VdMU0ikuQZ51VJKQ3WHRHEI104l+H tIbr9vRTRbNUIEmJOtYVt8skH0Z1qng3v9smI+qhXWJau3bmqdr3JkGf+4/CcgmuufuOC0jwK Gz5Zsh3Z9HAq76xJFJ3ssv8tcWMICmhER5wLTolkKipEdi/yBumo3t6QEZQy4gI5YblL5DQIH EP4dUDy/OSkQ1wctqBI2afZhan6AiEmbjJ5l1O4J7AwgiR2lOWlx8P0higytq00L6LQpvHNzZ Er88onHCNgYn69E7i+gnpxCRKLc5VOlGEm0gw/U5qx5+DoQ5YopYylY3gJxeQsM+bNT1M2xVY JHCBTvdA5CvT4+8M+6nPykt/ajQtG7Is+gbTBw9C5U715vpk5+j6qqOHSscSs17r7+nQgsgfC Jntx1sraZnpFBUs0BP14auKyjF8Yhxm3XhYbYm41KnO1XoT5U3aOQdYpslt07oZFR1Xd7LIHs ocgXgey27nfPWjXpq Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2020-10-12 at 20:34 +0200, Mike Galbraith wrote: > On Mon, 2020-10-12 at 18:45 +0200, Sebastian Andrzej Siewior wrote: > > On 2020-10-10 06:31:57 [+0200], Mike Galbraith wrote: > > > > so this then. Do you have more of these? > > Nope.... Well, I do have a gripe from 5.6-rt, which I just took a moment to confirm in virgin source, but that kernel is probably EOL. [ 24.613988] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ 24.613988] WARNING: possible circular locking dependency detected [ 24.613989] 5.6.19-rt12-rt #3 Tainted: G E [ 24.613990] ------------------------------------------------------ [ 24.613991] ksoftirqd/0/10 is trying to acquire lock: [ 24.613992] ffff94a639fd6a48 (&sch->q.lock){+...}, at: sch_direct_xmit+= 0x81/0x2f0 [ 24.613998] but task is already holding lock: [ 24.613998] ffff94a639fd6a80 (&(&sch->running)->seqcount){+...}, at: br= _dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614007] which lock already depends on the new lock. [ 24.614008] the existing dependency chain (in reverse order) is: [ 24.614009] -> #1 (&(&sch->running)->seqcount){+...}: [ 24.614010] __dev_queue_xmit+0xc86/0xda0 [ 24.614012] br_dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614017] br_forward_finish+0x10a/0x1b0 [bridge] [ 24.614021] __br_forward+0x17d/0x340 [bridge] [ 24.614024] br_dev_xmit+0x432/0x560 [bridge] [ 24.614029] dev_hard_start_xmit+0xc5/0x3f0 [ 24.614030] __dev_queue_xmit+0x973/0xda0 [ 24.614031] ip6_finish_output2+0x290/0x980 [ 24.614033] ip6_output+0x6d/0x260 [ 24.614034] mld_sendpack+0x1d9/0x360 [ 24.614035] mld_ifc_timer_expire+0x1f7/0x370 [ 24.614036] call_timer_fn+0x98/0x390 [ 24.614038] run_timer_softirq+0x591/0x720 [ 24.614040] __do_softirq+0xca/0x561 [ 24.614042] run_ksoftirqd+0x45/0x70 [ 24.614043] smpboot_thread_fn+0x266/0x320 [ 24.614045] kthread+0x11c/0x140 [ 24.614047] ret_from_fork+0x24/0x50 [ 24.614049] -> #0 (&sch->q.lock){+...}: [ 24.614050] __lock_acquire+0x115a/0x1440 [ 24.614052] lock_acquire+0x93/0x230 [ 24.614053] rt_spin_lock+0x78/0xd0 [ 24.614055] sch_direct_xmit+0x81/0x2f0 [ 24.614056] __dev_queue_xmit+0xcd7/0xda0 [ 24.614057] br_dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614062] br_forward_finish+0x10a/0x1b0 [bridge] [ 24.614067] __br_forward+0x17d/0x340 [bridge] [ 24.614072] br_dev_xmit+0x432/0x560 [bridge] [ 24.614076] dev_hard_start_xmit+0xc5/0x3f0 [ 24.614077] __dev_queue_xmit+0x973/0xda0 [ 24.614078] ip6_finish_output2+0x290/0x980 [ 24.614079] ip6_output+0x6d/0x260 [ 24.614080] mld_sendpack+0x1d9/0x360 [ 24.614081] mld_ifc_timer_expire+0x1f7/0x370 [ 24.614082] call_timer_fn+0x98/0x390 [ 24.614084] run_timer_softirq+0x591/0x720 [ 24.614085] __do_softirq+0xca/0x561 [ 24.614086] run_ksoftirqd+0x45/0x70 [ 24.614087] smpboot_thread_fn+0x266/0x320 [ 24.614089] kthread+0x11c/0x140 [ 24.614090] ret_from_fork+0x24/0x50 [ 24.614091] other info that might help us debug this: [ 24.614092] Possible unsafe locking scenario: [ 24.614092] CPU0 CPU1 [ 24.614093] ---- ---- [ 24.614093] lock(&(&sch->running)->seqcount); [ 24.614094] lock(&sch->q.lock); [ 24.614095] lock(&(&sch->running)->seqco= unt); [ 24.614096] lock(&sch->q.lock); [ 24.614097] *** DEADLOCK *** [ 24.614097] 20 locks held by ksoftirqd/0/10: [ 24.614098] #0: ffffffffa2485fc0 (rcu_read_lock){....}, at: rt_spin_lo= ck+0x5/0xd0 [ 24.614101] #1: ffff94a65ec1b5a0 (per_cpu_ptr(&bh_lock.lock, cpu)){...= .}, at: __local_bh_disable_ip+0xda/0x1c0 [ 24.614103] #2: ffffffffa2485fc0 (rcu_read_lock){....}, at: __local_bh= _disable_ip+0x106/0x1c0 [ 24.614105] #3: ffffffffa2485fc0 (rcu_read_lock){....}, at: rt_spin_lo= ck+0x5/0xd0 [ 24.614107] #4: ffff94a65ec1c1e0 (&base->expiry_lock){+...}, at: run_t= imer_softirq+0x3e3/0x720 [ 24.614110] #5: ffffb3bd40077d70 ((&idev->mc_ifc_timer)){+...}, at: ca= ll_timer_fn+0x5/0x390 [ 24.614113] #6: ffffffffa2485fc0 (rcu_read_lock){....}, at: mld_sendpa= ck+0x5/0x360 [ 24.614116] #7: ffffffffa2485fc0 (rcu_read_lock){....}, at: __local_bh= _disable_ip+0x106/0x1c0 [ 24.614118] #8: ffffffffa2485fa0 (rcu_read_lock_bh){....}, at: ip6_fin= ish_output2+0x7a/0x980 [ 24.614121] #9: ffffffffa2485fc0 (rcu_read_lock){....}, at: __local_bh= _disable_ip+0x106/0x1c0 [ 24.614124] #10: ffffffffa2485fa0 (rcu_read_lock_bh){....}, at: __dev_= queue_xmit+0x63/0xda0 [ 24.614126] #11: ffffffffa2485fc0 (rcu_read_lock){....}, at: br_dev_xm= it+0x5/0x560 [bridge] [ 24.614133] #12: ffffffffa2485fc0 (rcu_read_lock){....}, at: __local_b= h_disable_ip+0x106/0x1c0 [ 24.614135] #13: ffffffffa2485fa0 (rcu_read_lock_bh){....}, at: __dev_= queue_xmit+0x63/0xda0 [ 24.614138] #14: ffffffffa2485fc0 (rcu_read_lock){....}, at: rt_spin_l= ock+0x5/0xd0 [ 24.614140] #15: ffff94a639fd6d60 (&dev->qdisc_tx_busylock_key){+...},= at: __dev_queue_xmit+0x89e/0xda0 [ 24.614143] #16: ffffffffa2485fc0 (rcu_read_lock){....}, at: rt_spin_l= ock+0x5/0xd0 [ 24.614145] #17: ffff94a639fd6b40 (&dev->qdisc_running_key){+...}, at:= __dev_queue_xmit+0xc52/0xda0 [ 24.614148] #18: ffff94a639fd6a80 (&(&sch->running)->seqcount){+...}, = at: br_dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614154] #19: ffffffffa2485fc0 (rcu_read_lock){....}, at: rt_spin_l= ock+0x5/0xd0 [ 24.614155] stack backtrace: [ 24.614156] CPU: 0 PID: 10 Comm: ksoftirqd/0 Kdump: loaded Tainted: G = E 5.6.19-rt12-rt #3 [ 24.614157] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09= /23/2013 [ 24.614158] Call Trace: [ 24.614160] dump_stack+0x71/0x9b [ 24.614163] check_noncircular+0x155/0x170 [ 24.614166] ? __lock_acquire+0x115a/0x1440 [ 24.614168] __lock_acquire+0x115a/0x1440 [ 24.614172] lock_acquire+0x93/0x230 [ 24.614173] ? sch_direct_xmit+0x81/0x2f0 [ 24.614177] rt_spin_lock+0x78/0xd0 [ 24.614178] ? sch_direct_xmit+0x81/0x2f0 [ 24.614180] sch_direct_xmit+0x81/0x2f0 [ 24.614182] __dev_queue_xmit+0xcd7/0xda0 [ 24.614184] ? find_held_lock+0x2d/0x90 [ 24.614186] ? br_forward_finish+0xde/0x1b0 [bridge] [ 24.614192] ? br_dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614197] br_dev_queue_push_xmit+0x79/0x160 [bridge] [ 24.614203] br_forward_finish+0x10a/0x1b0 [bridge] [ 24.614210] __br_forward+0x17d/0x340 [bridge] [ 24.614216] ? br_flood+0x98/0x120 [bridge] [ 24.614222] br_dev_xmit+0x432/0x560 [bridge] [ 24.614228] dev_hard_start_xmit+0xc5/0x3f0 [ 24.614232] __dev_queue_xmit+0x973/0xda0 [ 24.614233] ? mark_held_locks+0x2d/0x80 [ 24.614235] ? eth_header+0x25/0xc0 [ 24.614238] ? ip6_finish_output2+0x290/0x980 [ 24.614239] ip6_finish_output2+0x290/0x980 [ 24.614242] ? ip6_mtu+0x135/0x1b0 [ 24.614246] ? ip6_output+0x6d/0x260 [ 24.614247] ip6_output+0x6d/0x260 [ 24.614249] ? __ip6_finish_output+0x210/0x210 [ 24.614252] mld_sendpack+0x1d9/0x360 [ 24.614255] ? mld_ifc_timer_expire+0x119/0x370 [ 24.614256] mld_ifc_timer_expire+0x1f7/0x370 [ 24.614258] ? mld_dad_timer_expire+0xb0/0xb0 [ 24.614259] ? mld_dad_timer_expire+0xb0/0xb0 [ 24.614260] call_timer_fn+0x98/0x390 [ 24.614263] ? mld_dad_timer_expire+0xb0/0xb0 [ 24.614264] run_timer_softirq+0x591/0x720 [ 24.614267] __do_softirq+0xca/0x561 [ 24.614271] ? smpboot_thread_fn+0x28/0x320 [ 24.614273] ? smpboot_thread_fn+0x70/0x320 [ 24.614274] run_ksoftirqd+0x45/0x70 [ 24.614275] smpboot_thread_fn+0x266/0x320 [ 24.614277] ? smpboot_register_percpu_thread+0xe0/0xe0 [ 24.614278] kthread+0x11c/0x140 [ 24.614280] ? kthread_park+0x90/0x90 [ 24.614282] ret_from_fork+0x24/0x50