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From: "Paul E. McKenney" <paulmck@kernel.org>
To: tj@kernel.org, jiangshanlai@gmail.com
Cc: linux-kernel@vger.kernel.org
Subject: Workqueues splat due to ending up on wrong CPU
Date: Mon, 25 Nov 2019 15:03:12 -0800	[thread overview]
Message-ID: <20191125230312.GP2889@paulmck-ThinkPad-P72> (raw)

Hello!

I am seeing this occasionally during rcutorture runs in the presence
of CPU hotplug.  This is on v5.4-rc1 in process_one_work() at the first
WARN_ON():

	WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
		     raw_smp_processor_id() != pool->cpu);

What should I do to help further debug this?

							Thanx, Paul

------------------------------------------------------------------------

[ 7119.309435] WARNING: CPU: 1 PID: 4 at kernel/workqueue.c:2179 process_one_work+0x86/0x510
[ 7119.310449] Modules linked in:
[ 7119.310849] CPU: 1 PID: 4 Comm: rcu_par_gp Not tainted 5.4.0-rc1+ #21
[ 7119.311656] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.11.0-2.el7 04/01/2014
[ 7119.312693] RIP: 0010:process_one_work+0x86/0x510
[ 7119.313250] Code: ee 05 48 89 44 24 10 48 8b 46 38 41 83 e6 01 41 f6 44 24 44 04 48 89 44 24 28 75 10 65 8b 05 39 7d 98 7b 41 3b 44 24 38 74 02 <0f> 0b 48 89 de 4c 89 e7 e8 7d cd ff ff 48 85 c0 0f 85 0e 04 00 00
[ 7119.315555] RSP: 0000:ffff9aba4002fe30 EFLAGS: 00010002
[ 7119.316189] RAX: 0000000000000001 RBX: ffffffff85c65f68 RCX: 0000000000000000
[ 7119.317064] RDX: ffff97a5df22d400 RSI: ffffffff85c65f68 RDI: ffff97a5dec95600
[ 7119.317943] RBP: ffff97a5dec95600 R08: ffffffff85c65f70 R09: ffffffff86856140
[ 7119.318812] R10: 0000000000000000 R11: 0000000000000001 R12: ffff97a5df228a80
[ 7119.319703] R13: ffff97a5df22d400 R14: 0000000000000000 R15: ffff97a5dec95600
[ 7119.320602] FS:  0000000000000000(0000) GS:ffff97a5df240000(0000) knlGS:0000000000000000
[ 7119.321581] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7119.322301] CR2: 0000000000000148 CR3: 0000000015c1e000 CR4: 00000000000006e0
[ 7119.323188] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7119.324069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7119.324957] Call Trace:
[ 7119.325288]  rescuer_thread+0x1b5/0x2e0
[ 7119.325772]  kthread+0xf3/0x130
[ 7119.326164]  ? worker_thread+0x3c0/0x3c0
[ 7119.326655]  ? kthread_cancel_delayed_work_sync+0x10/0x10
[ 7119.327349]  ret_from_fork+0x35/0x40
[ 7119.327795] ---[ end trace 6dd6d520676d8e8e ]---

             reply	other threads:[~2019-11-25 23:03 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-25 23:03 Paul E. McKenney [this message]
2019-11-26 18:33 ` Workqueues splat due to ending up on wrong CPU Tejun Heo
2019-11-26 22:05   ` Paul E. McKenney
2019-11-27 15:50     ` Paul E. McKenney
2019-11-28 16:18       ` Paul E. McKenney
2019-11-29 15:58         ` Paul E. McKenney
2019-12-02  1:55           ` Paul E. McKenney
2019-12-02 20:13             ` Tejun Heo
2019-12-02 23:39               ` Paul E. McKenney
2019-12-03 10:00                 ` Peter Zijlstra
2019-12-03 17:45                   ` Paul E. McKenney
2019-12-03 18:13                     ` Tejun Heo
2019-12-03  9:55               ` Peter Zijlstra
2019-12-03 10:06                 ` Peter Zijlstra
2019-12-03 15:42                 ` Tejun Heo
2019-12-03 16:04                   ` Paul E. McKenney
2019-12-04 20:11                 ` Paul E. McKenney
2019-12-05 10:29                   ` Peter Zijlstra
2019-12-05 10:32                     ` Peter Zijlstra
2019-12-05 14:48                       ` Paul E. McKenney
2019-12-06  3:19                         ` Paul E. McKenney
2019-12-06 18:52                         ` Paul E. McKenney
2019-12-06 22:00                           ` Paul E. McKenney
2019-12-09 18:59                             ` Paul E. McKenney
2019-12-10  9:08                               ` Peter Zijlstra
2019-12-10 22:56                                 ` Paul E. McKenney

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