From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB0081FB1; Sat, 5 Sep 2026 00:42:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788568979; cv=none; b=iKrX6BSp6VRQm6QVrhmbyI/ialG3ZP8hZNCGjlga76AfVMrlRTgbkFAZ74OmQMMl1SD1RvAltZ6M+kMTdMDgensvMqUAcvyVGiIxwG13R4bnFyDHkVdihmf8pbNo/SnFBifMyeJNUtzj2eKfsC7Qc5tmDAZL0jG6D/G9jgzo2bE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788568979; c=relaxed/simple; bh=Zv1r3FIV6pbmYSAwd1bOTjGOlyPD1z7k1E4/q/elccI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kw9L4YZol4t0tjifOy9rpzD53+xHtiwbFQQYXNaj6tjPK6UJBkOEeCLdxHOpqOCglTNYajnnWfC4KxecU0HAaDF1k8miXAXPRLIGr6s6K9xbePxVP93d1vcxuZeEWjVKh6J/PWYhGjqVhh98xnVPbAVORKhGMvDeumV0u6/s0Zs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=TxE/3w0B; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="TxE/3w0B" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1788568973; h=Date:From:To:Subject:Message-ID:MIME-Version:Content-Type; bh=rXC4fBzFvtgZ7XyuwFm+it0/0aIEWSMMEm5oqcrJXGI=; b=TxE/3w0Be39Uzl9tuYQ2Lrvc+OXyBcfQoncQ2mKFK5oDZtn2ChMGWRmQzG18bcbg3QP+857b1KWwwoS2jwUDsN2LhmS/JPUIVDx5OW1ALz4P20wP7rVvATFNqPJ0c2T1iuq5J0bMOs8dKexGkXtnR45Fy97Pj/M3W+qflX4VJkg= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R541e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=dust.li@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0XAJoxoc_1788568971; Received: from localhost(mailfrom:dust.li@linux.alibaba.com fp:SMTPD_---0XAJoxoc_1788568971 cluster:ay36) by smtp.aliyun-inc.com; Sat, 05 Sep 2026 08:42:52 +0800 Date: Sat, 5 Sep 2026 08:42:51 +0800 From: Dust Li To: Alexandra Winter , "D. Wythe" , Sidraya Jayagond , Mahanta Jambigi , David Miller , Jakub Kicinski , Paolo Abeni , Eric Dumazet , Andrew Lunn Cc: Tony Lu , Wen Gu , netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Simon Horman Subject: Re: [PATCH net-next] dibs: Avoid inconsistent lockstate warning in dibs_lo_move_data() Message-ID: Reply-To: dust.li@linux.alibaba.com References: <20260904094446.1342654-1-wintera@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260904094446.1342654-1-wintera@linux.ibm.com> On 2026-09-04 11:44:46, Alexandra Winter wrote: >dibs->lock is acquired in process context and interrupt context >(ism_handle_irq()). So always use spin_lock_irqsave() in process context. > >Note that this is not a real deadlock, as dibs_lo devices don't have >any interrupt context. > >Example warning: >[ 153.760872] ================================ >[ 153.760878] WARNING: inconsistent lock state >[ 153.760885] 7.2.0-15871-g544d85de4dc2 #16 Not tainted >[ 153.760891] -------------------------------- >[ 153.760896] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. >[ 153.760901] python3/5134 [HC0[0]:SC0[2]:HE1:SE0] takes: >[ 153.760909] 0001222c0fe72428 (&dibs->lock){?...}-{2:2}, at: dibs_lo_move_data+0x1ce/0x380 >[ 153.760932] {IN-HARDIRQ-W} state was registered at: >[ 153.760937] __lock_acquire+0x59c/0x15d0 >[ 153.760947] lock_acquire.part.0+0x11c/0x290 >[ 153.760953] lock_acquire+0xb4/0x1e0 >[ 153.760959] _raw_spin_lock+0x58/0xb0 >[ 153.760966] ism_handle_irq+0x80/0x3f0 [ism] >[ 153.760974] __handle_irq_event_percpu+0x282/0x920 >[ 153.760983] handle_irq_event_percpu+0x26/0xe0 >[ 153.760989] handle_percpu_irq+0x10e/0x1a0 >[ 153.760997] handle_irq_desc+0xa6/0x100 >[ 153.761003] zpci_floating_irq_handler+0x3ca/0x610 >[ 153.761011] do_airq_interrupt+0x206/0x500 >[ 153.761018] __handle_irq_event_percpu+0x282/0x920 >[ 153.761025] handle_irq_event_percpu+0x26/0xe0 >[ 153.761031] handle_percpu_irq+0x10e/0x1a0 >[ 153.761039] handle_irq_desc+0xa6/0x100 >[ 153.761045] do_irq_async+0xec/0x150 >[ 153.761052] do_io_irq+0x150/0x2e0 >[ 153.761060] io_int_handler+0xec/0x118 >[ 153.761066] arch_cpu_idle+0x120/0x130 >[ 153.761118] arch_cpu_idle+0xbe/0x130 >[ 153.761124] s390_enter_idle+0x20/0x30 >[ 153.761131] cpuidle_enter_state+0xb6/0x440 >[ 153.761138] cpuidle_enter+0x64/0xb0 >[ 153.761144] cpuidle_idle_call+0x174/0x380 >[ 153.761151] do_idle+0x16e/0x250 >[ 153.761157] cpu_startup_entry+0x70/0x80 >[ 153.761163] smp_start_secondary+0x36e/0x440 >[ 153.761171] restart_int_handler+0x72/0x88 >[ 153.761178] irq event stamp: 46536 >[ 153.761182] hardirqs last enabled at (46536): [<000127b697450a90>] __local_bh_enable_ip+0x140/0x270 >[ 153.761193] hardirqs last disabled at (46535): [<000127b697450b20>] __local_bh_enable_ip+0x1d0/0x270 >[ 153.761202] softirqs last enabled at (46532): [<000127b6185f82c8>] smc_close_active+0x438/0xba0 [smc] >[ 153.761232] softirqs last disabled at (46534): [<000127b6185ee998>] smc_cdc_get_slot_and_msg_send+0x218/0x370 [smc] >[ 153.761257] > other info that might help us debug this: >[ 153.761262] Possible unsafe locking scenario: > >[ 153.761267] CPU0 >[ 153.761271] ---- >[ 153.761274] lock(&dibs->lock); >[ 153.761282] >[ 153.761286] lock(&dibs->lock); >[ 153.761294] > *** DEADLOCK *** > >[ 153.761299] locks held by python3/5134: 3, last CPU#1: >[ 153.761305] #0: 0001222bab975f50 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release+0x7e/0x230 >[ 153.761329] #1: 0001222ba5450378 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_close_active+0x438/0xba0 [smc] >[ 153.761360] #2: 0001222ba54508a0 (&smc->conn.send_lock){+...}-{2:2}, at: smc_cdc_get_slot_and_msg_send+0x218/0x370 [smc] >[ 153.761394] > stack backtrace: >[ 153.761400] CPU: 1 UID: 0 PID: 5134 Comm: python3 Not tainted 7.2.0-15871-g544d85de4dc2 #16 PREEMPT >[ 153.761406] Hardware name: IBM 3931 A01 703 (LPAR) >[ 153.761408] Call Trace: >[ 153.761409] [<000127b697366190>] dump_stack_lvl+0xe8/0x140 >[ 153.761415] [<000127b6975ccc8c>] print_usage_bug.part.0+0x2ec/0x3a0 >[ 153.761419] [<000127b6975cd454>] mark_lock_irq+0x714/0xa20 >[ 153.761422] [<000127b6975cda52>] mark_lock+0x2f2/0x790 >[ 153.761426] [<000127b6975ce2e6>] mark_usage+0x136/0x1c0 >[ 153.761430] [<000127b6975ce90c>] __lock_acquire+0x59c/0x15d0 >[ 153.761433] [<000127b6975cfa5c>] lock_acquire.part.0+0x11c/0x290 >[ 153.761437] [<000127b6975cfc84>] lock_acquire+0xb4/0x1e0 >[ 153.761441] [<000127b699d02a98>] _raw_spin_lock+0x58/0xb0 >[ 153.761444] [<000127b6992ca4fe>] dibs_lo_move_data+0x1ce/0x380 >[ 153.761449] [<000127b6185f0912>] smcd_tx_ism_write+0x182/0x250 [smc] >[ 153.761469] [<000127b6185ee4c6>] smcd_cdc_msg_send+0x156/0x410 [smc] >[ 153.761487] [<000127b6185ee9a2>] smc_cdc_get_slot_and_msg_send+0x222/0x370 [smc] >[ 153.761507] [<000127b6185f8370>] smc_close_active+0x4e0/0xba0 [smc] >[ 153.761526] [<000127b6185a293c>] __smc_release+0x4ac/0x6a0 [smc] >[ 153.761546] [<000127b6185a2c6e>] smc_release+0x13e/0x480 [smc] >[ 153.761565] [<000127b6994544d4>] __sock_release+0xa4/0x230 >[ 153.761569] [<000127b69945468c>] sock_close+0x2c/0x40 >[ 153.761573] [<000127b697e57180>] __fput+0x2f0/0x880 >[ 153.761579] [<000127b697e58440>] fput_close_sync+0xd0/0x1c0 >[ 153.761583] [<000127b697e4b3f0>] __s390x_sys_close+0x90/0xf0 >[ 153.761586] [<000127b699cdc19e>] __do_syscall+0x1be/0x5a0 >[ 153.761590] [<000127b699d04c7a>] system_call+0x72/0x90 >[ 153.761594] INFO: lockdep is turned off. > >Signed-off-by: Alexandra Winter Reviewed-by: Dust Li Best regards, Dust