Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752237AbdHJDse (ORCPT ); Wed, 9 Aug 2017 23:48:34 -0400 Received: from LGEAMRELO13.lge.com ([156.147.23.53]:35199 "EHLO lgeamrelo13.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752174AbdHJDsd (ORCPT ); Wed, 9 Aug 2017 23:48:33 -0400 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Thu, 10 Aug 2017 12:47:18 +0900 From: Byungchul Park To: Peter Zijlstra 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: <20170810034718.GZ20323@X58A-UD3R> References: <1502089981-21272-1-git-send-email-byungchul.park@lge.com> <20170809155059.yd7le2szn2rcd4h2@hirez.programming.kicks-ass.net> <20170810005556.GU20323@X58A-UD3R> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170810005556.GU20323@X58A-UD3R> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5688 Lines: 149 On Thu, Aug 10, 2017 at 09:55:56AM +0900, Byungchul Park wrote: > On Wed, Aug 09, 2017 at 05:50:59PM +0200, Peter Zijlstra wrote: > > > > > > Heh, look what it does... > > It does not happen in my machine.. > > I tihink it happens because of "Simplify xhlock ring buffer invalidation" > patch of you. > > First of all, could you reverse yours and check if it happens, too? > If not, we have to think the simplification more. > > BTW, does your patch consider the possibility that a worker and irqs can > be nested? Is it no problem even in the case? In addition, now that each syscall context is isolated by your suggestion with crossrelease_hist_end() and crossrelease_hist_start(), contexts can be nested easily. I want to keep my patches unchanged at first and change code carefully. > > > > > > > 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