Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753517AbdHIPvP (ORCPT ); Wed, 9 Aug 2017 11:51:15 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54756 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752383AbdHIPvN (ORCPT ); Wed, 9 Aug 2017 11:51:13 -0400 Date: Wed, 9 Aug 2017 17:50:59 +0200 From: Peter Zijlstra To: Byungchul Park Cc: mingo@kernel.org, tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, willy@infradead.org, npiggin@gmail.com, kernel-team@lge.com Subject: Re: [PATCH v8 00/14] lockdep: Implement crossrelease feature Message-ID: <20170809155059.yd7le2szn2rcd4h2@hirez.programming.kicks-ass.net> References: <1502089981-21272-1-git-send-email-byungchul.park@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1502089981-21272-1-git-send-email-byungchul.park@lge.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4414 Lines: 129 Heh, look what it does... 4====================================================== 4WARNING: possible circular locking dependency detected 4.13.0-rc2-00317-gadc6764a3adf-dirty #797 Tainted: G W 4------------------------------------------------------ 4startpar/582 is trying to acquire lock: c (c(complete)&barr->donec){+.+.}c, at: [] flush_work+0x1fd/0x2c0 4 but task is already holding lock: c (clockc#3c){+.+.}c, at: [] lru_add_drain_all_cpuslocked+0x46/0x1a0 4 which lock already depends on the new lock. 4 the existing dependency chain (in reverse order) is: -> #4c (clockc#3c){+.+.}c: __lock_acquire+0x10a5/0x1100 lock_acquire+0xea/0x1f0 __mutex_lock+0x6c/0x960 mutex_lock_nested+0x1b/0x20 lru_add_drain_all_cpuslocked+0x46/0x1a0 lru_add_drain_all+0x13/0x20 SyS_mlockall+0xb8/0x1c0 entry_SYSCALL_64_fastpath+0x23/0xc2 -> #3c (ccpu_hotplug_lock.rw_semc){++++}c: __lock_acquire+0x10a5/0x1100 lock_acquire+0xea/0x1f0 cpus_read_lock+0x2a/0x90 kmem_cache_create+0x2a/0x1d0 scsi_init_sense_cache+0xa0/0xc0 scsi_add_host_with_dma+0x67/0x360 isci_pci_probe+0x873/0xc90 local_pci_probe+0x42/0xa0 work_for_cpu_fn+0x14/0x20 process_one_work+0x273/0x6b0 worker_thread+0x21b/0x3f0 kthread+0x147/0x180 ret_from_fork+0x2a/0x40 -> #2c (cscsi_sense_cache_mutexc){+.+.}c: __lock_acquire+0x10a5/0x1100 lock_acquire+0xea/0x1f0 __mutex_lock+0x6c/0x960 mutex_lock_nested+0x1b/0x20 scsi_init_sense_cache+0x3d/0xc0 scsi_add_host_with_dma+0x67/0x360 isci_pci_probe+0x873/0xc90 local_pci_probe+0x42/0xa0 work_for_cpu_fn+0x14/0x20 process_one_work+0x273/0x6b0 worker_thread+0x21b/0x3f0 kthread+0x147/0x180 ret_from_fork+0x2a/0x40 -> #1c (c(&wfc.work)c){+.+.}c: process_one_work+0x244/0x6b0 worker_thread+0x21b/0x3f0 kthread+0x147/0x180 ret_from_fork+0x2a/0x40 0xffffffffffffffff -> #0c (c(complete)&barr->donec){+.+.}c: check_prev_add+0x3be/0x700 __lock_acquire+0x10a5/0x1100 lock_acquire+0xea/0x1f0 wait_for_completion+0x3b/0x130 flush_work+0x1fd/0x2c0 lru_add_drain_all_cpuslocked+0x158/0x1a0 lru_add_drain_all+0x13/0x20 SyS_mlockall+0xb8/0x1c0 entry_SYSCALL_64_fastpath+0x23/0xc2 other info that might help us debug this: Chain exists of: c(complete)&barr->donec --> ccpu_hotplug_lock.rw_semc --> clockc#3c Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(clockc#3c); lock(ccpu_hotplug_lock.rw_semc); lock(clockc#3c); lock(c(complete)&barr->donec); *** DEADLOCK *** 2 locks held by startpar/582: #0: c (ccpu_hotplug_lock.rw_semc){++++}c, at: [] lru_add_drain_all+0xe/0x20 #1: c (clockc#3c){+.+.}c, at: [] lru_add_drain_all_cpuslocked+0x46/0x1a0 stack backtrace: dCPU: 23 PID: 582 Comm: startpar Tainted: G W 4.13.0-rc2-00317-gadc6764a3adf-dirty #797 dHardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 dCall Trace: d dump_stack+0x86/0xcf d print_circular_bug+0x203/0x2f0 d check_prev_add+0x3be/0x700 d ? add_lock_to_list.isra.30+0xc0/0xc0 d ? is_bpf_text_address+0x82/0xe0 d ? unwind_get_return_address+0x1f/0x30 d __lock_acquire+0x10a5/0x1100 d ? __lock_acquire+0x10a5/0x1100 d ? add_lock_to_list.isra.30+0xc0/0xc0 d lock_acquire+0xea/0x1f0 d ? flush_work+0x1fd/0x2c0 d wait_for_completion+0x3b/0x130 d ? flush_work+0x1fd/0x2c0 d flush_work+0x1fd/0x2c0 d ? flush_workqueue_prep_pwqs+0x1c0/0x1c0 d ? trace_hardirqs_on+0xd/0x10 d lru_add_drain_all_cpuslocked+0x158/0x1a0 d lru_add_drain_all+0x13/0x20 d SyS_mlockall+0xb8/0x1c0 d entry_SYSCALL_64_fastpath+0x23/0xc2 dRIP: 0033:0x7f818d2e54c7 dRSP: 002b:00007fffcce83798 EFLAGS: 00000246c ORIG_RAX: 0000000000000097 dRAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f818d2e54c7 dRDX: 0000000000000000 RSI: 00007fffcce83650 RDI: 0000000000000003 dRBP: 000000000002c010 R08: 0000000000000000 R09: 0000000000000000 dR10: 0000000000000008 R11: 0000000000000246 R12: 000000000002d000 dR13: 000000000002c010 R14: 0000000000001000 R15: 00007f818d599b00