Hi Tejun, > Bluetooth hci uses ordered HIGHPRI, MEM_RECLAIM workqueues. It's > likely that the flags came from mechanical conversion from > create_singlethread_workqueue(). Bluetooth shouldn't be depended upon > for memory reclaim and the spurious MEM_RECLAIM flag can trigger the > following warning. Remove WQ_MEM_RECLAIM and convert to > alloc_ordered_workqueue() while at it. > > workqueue: WQ_MEM_RECLAIM hci0:hci_power_off is flushing !WQ_MEM_RECLAIM events:btusb_work > ------------[ cut here ]------------ > WARNING: CPU: 2 PID: 14231 at /home/brodo/local/kernel/git/linux/kernel/workqueue.c:2423 check_flush_dependency+0xb3/0x100 > Modules linked in: > CPU: 2 PID: 14231 Comm: kworker/u9:4 Not tainted 4.12.0-rc6+ #3 > Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016 > Workqueue: hci0 hci_power_off > task: ffff9432dad58000 task.stack: ffff986d43790000 > RIP: 0010:check_flush_dependency+0xb3/0x100 > RSP: 0018:ffff986d43793c90 EFLAGS: 00010086 > RAX: 000000000000005a RBX: ffff943316810820 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000096 RDI: 0000000000000001 > RBP: ffff986d43793cb0 R08: 0000000000000775 R09: ffffffff85bdd5c0 > R10: 0000000000000040 R11: 0000000000000000 R12: ffffffff84d596e0 > R13: ffff9432dad58000 R14: ffff94321c640320 R15: ffff9432dad58000 > FS: 0000000000000000(0000) GS:ffff94331f500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007b8bca242000 CR3: 000000014f60a000 CR4: 00000000003406e0 > Call Trace: > flush_work+0x8a/0x1c0 > ? flush_work+0x184/0x1c0 > ? skb_free_head+0x21/0x30 > __cancel_work_timer+0x124/0x1b0 > ? hci_dev_do_close+0x2a4/0x4d0 > cancel_work_sync+0x10/0x20 > btusb_close+0x23/0x100 > hci_dev_do_close+0x2ca/0x4d0 > hci_power_off+0x1e/0x50 > process_one_work+0x184/0x3e0 > worker_thread+0x4a/0x3a0 > ? preempt_count_sub+0x9b/0x100 > ? preempt_count_sub+0x9b/0x100 > kthread+0x125/0x140 > ? process_one_work+0x3e0/0x3e0 > ? __kthread_create_on_node+0x1a0/0x1a0 > ? do_syscall_64+0x58/0xd0 > ret_from_fork+0x27/0x40 > Code: 00 75 bf 49 8b 56 18 48 8d 8b b0 00 00 00 48 81 c6 b0 00 00 00 4d 89 e0 48 c7 c7 20 23 6b 85 c6 05 83 cd 31 01 01 e8 bf c4 0c 00 <0f> ff eb 93 80 3d 74 cd 31 01 00 75 a5 65 48 8b 04 25 00 c5 00 > ---[ end trace b88fd2f77754bfec ]--- > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Reported-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> > --- > Hello, > > Marcel, as this isn't urgent and there is slight chance that this > might trigger another warning if these work items get flushed from a > different MEM_RECLAIM work item from e.g. nfs over network over > bluetooth. Can you please try applying the patch after the 4.13-rc1 > closes and see whether it turns up anything else? > > Thanks. > > net/bluetooth/hci_core.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) patch has been applied to bluetooth-next tree. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
