Re: 3.8-rc2: pciehp waitqueue hang...

[Bjorn Helgaas]

[+to Yijing, +cc Kenji]

On Fri, Jan 4, 2013 at 1:01 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
> On Thu, Jan 3, 2013 at 8:41 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote:
>> Hi Daniel,
>>         It seems like an issue caused by recursive PCIe HPC.
>> Could you please help to try the patch from:
>> http://www.spinics.net/lists/linux-pci/msg18625.html
>
> Hi Gerry,
>
> I'm working on merging this patch.  Seems like something that might be
> appropriate for stable as well.
>
> Did you look for similar problems in other hotplug drivers?

Oops, sorry, I forgot that Yijing is the author of the patch in question.

Yijing, please check for the same problem in other hotplug drivers.
Questions I have after a quick look:

  - shpchp_wq looks like it might have the same deadlock issue.

  - pciehp_wq (and your per-slot replacement) are allocated with
alloc_workqueue().  shpchp_wq is allocated with
alloc_ordered_workqueue().  Why the difference?

  - The alloc/alloc_ordered difference might be related to 486b10b9f4,
where Kenji removed alloc_ordered from pciehp.  Should a similar
change be made to shpchp?

  - acpiphp uses the global kacpi_hotplug_wq.  We never flush or drain
kacpi_hotplug_wq, so I doubt there's a deadlock issue, but I wonder if
there are any ordering issues there because we *don't* ever wait for
things in that queue to be completed.

>> Thanks!
>> Gerry
>> On 01/03/2013 11:11 PM, Daniel J Blueman wrote:
>>> When the Apple thunderbolt ethernet adapter comes loose on my Macbook
>>> Pro Retina (Intel DSL3510), we see pci_slot_name return
>>> non-deterministic data (ie varying each boot), and we see pciehp_wp
>>> remain armed with events causing the kthread to get stuck:
>>>
>>> tg3 0000:0a:00.0 eth0: Link is up at 1000 Mbps, full duplex
>>> tg3 0000:0a:00.0 eth0: Flow control is on for TX and on for RX
>>> <thunderbold adapter comes loose>
>>> pciehp 0000:06:03.0:pcie24: Card not present on Slot(3)
>>> tg3 0000:0a:00.0: tg3_abort_hw timed out, TX_MODE_ENABLE will not
>>> clear MAC_TX_MODE=ffffffff
>>> tg3 0000:0a:00.0 eth0: No firmware running
>>> tg3 0000:0a:00.0 eth0: Link is down
>>> pcieport 0000:00:01.1: System wakeup enabled by ACPI
>>> pciehp 0000:09:00.0:pcie24: unloading service driver pciehp
>>> pciehp 0000:09:00.0:pcie24: Latch open on
>>> Slot(\xfffffff89\xffffffbbe\x02\xffffff88\xffffffff\xffffffff\xffffffe09\xffffffbbe\x02\xffffff88\xffffffff\xfffffffffbcon)
>>> pciehp 0000:09:00.0:pcie24: Button pressed on
>>> Slot(\xfffffff89\xffffffbbe\x02\xffffff88\xffffffff\xffffffff\xffffffe09\xffffffbbe\x02\xffffff88\xffffffff\xfffffffffbcon)
>>> pciehp 0000:09:00.0:pcie24: Card present on
>>> Slot(\xfffffff89\xffffffbbe\x02\xffffff88\xffffffff\xffffffff\xffffffe09\xffffffbbe\x02\xffffff88\xffffffff\xfffffffffbcon)
>>> pciehp 0000:09:00.0:pcie24: Power fault on slot
>>> \xfffffff89\xffffffbbe\x02\xffffff88\xffffffff\xffffffff\xffffffe09\xffffffbbe\x02\xffffff88\xffffffff\xfffffffffbcon
>>> pciehp 0000:09:00.0:pcie24: Power fault bit 0 set
>>> pciehp 0000:09:00.0:pcie24: PCI slot
>>> #\xfffffff89\xffffffbbe\x02\xffffff88\xffffffff\xffffffff\xffffffe09\xffffffbbe\x02\xffffff88\xffffffff\xfffffffffbcon
>>> - powering on due to button press.
>>> pciehp 0000:09:00.0:pcie24: Link Training Error occurs
>>> pciehp 0000:09:00.0:pcie24: Failed to check link status
>>> INFO: task kworker/0:1:52 blocked for more than 120 seconds.
>>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>>> kworker/0:1   D ffff880265893090   0  52   2 0x00000000
>>>  ffff8802655456f8 0000000000000046 ffffffff81a21a60 ffff880265545fd8
>>>  0000000000004000 ffff880265545fd8 ffff880265892bb0 ffff880265adc8d0
>>>  000000000000059e 0000000000000082 ffff880265545668 ffffffff810415aa
>>> Call Trace:
>>>  [<ffffffff810415aa>] ? console_unlock+0x1fa/0x4a0
>>>  [<ffffffff8108d16d>] ? trace_hardirqs_off+0xd/0x10
>>>  [<ffffffff81041b19>] ? vprintk_emit+0x1c9/0x510
>>>  [<ffffffff81558db4>] schedule+0x24/0x70
>>>  [<ffffffff8155653c>] schedule_timeout+0x19c/0x1e0
>>>  [<ffffffff81558c43>] wait_for_common+0xe3/0x180
>>>  [<ffffffff8105adc1>] ? flush_workqueue+0x111/0x4d0
>>>  [<ffffffff81071140>] ? try_to_wake_up+0x2d0/0x2d0
>>>  [<ffffffff81558d88>] wait_for_completion+0x18/0x20
>>>  [<ffffffff8105ae86>] flush_workqueue+0x1d6/0x4d0
>>>  [<ffffffff8105acb0>] ? flush_workqueue_prep_cwqs+0x200/0x200
>>>  [<ffffffff8125e909>] pciehp_release_ctrl+0x39/0x90
>>>  [<ffffffff8125b945>] pciehp_remove+0x25/0x30
>>>  [<ffffffff81255bf2>] pcie_port_remove_service+0x52/0x70
>>>  [<ffffffff81306a27>] __device_release_driver+0x77/0xe0
>>>  [<ffffffff81306ab9>] device_release_driver+0x29/0x40
>>>  [<ffffffff813064b1>] bus_remove_device+0xf1/0x140
>>>  [<ffffffff81303fe7>] device_del+0x127/0x1c0
>>>  [<ffffffff81255d70>] ? resume_iter+0x40/0x40
>>>  [<ffffffff81304091>] device_unregister+0x11/0x20
>>>  [<ffffffff81255da5>] remove_iter+0x35/0x40
>>>  [<ffffffff81302eb6>] device_for_each_child+0x36/0x70
>>>  [<ffffffff81256341>] pcie_port_device_remove+0x21/0x40
>>>  [<ffffffff81256588>] pcie_portdrv_remove+0x28/0x50
>>>  [<ffffffff8124a821>] pci_device_remove+0x41/0xc0
>>>  [<ffffffff81306a27>] __device_release_driver+0x77/0xe0
>>>  [<ffffffff81306ab9>] device_release_driver+0x29/0x40
>>>  [<ffffffff813064b1>] bus_remove_device+0xf1/0x140
>>>  [<ffffffff81303fe7>] device_del+0x127/0x1c0
>>>  [<ffffffff81304091>] device_unregister+0x11/0x20
>>>  [<ffffffff8124566c>] pci_stop_bus_device+0x8c/0xa0
>>>  [<ffffffff81245615>] pci_stop_bus_device+0x35/0xa0
>>>  [<ffffffff81245811>] pci_stop_and_remove_bus_device+0x11/0x20
>>>  [<ffffffff8125cc91>] pciehp_unconfigure_device+0x91/0x190
>>>  [<ffffffff8125c76d>] ? pciehp_power_thread+0x2d/0x110
>>>  [<ffffffff8125c591>] pciehp_disable_slot+0x71/0x220
>>>  [<ffffffff8125c826>] pciehp_power_thread+0xe6/0x110
>>>  [<ffffffff8105d203>] process_one_work+0x193/0x550
>>>  [<ffffffff8105d1a1>] ? process_one_work+0x131/0x550
>>>  [<ffffffff8125c740>] ? pciehp_disable_slot+0x220/0x220
>>>  [<ffffffff8105d96d>] worker_thread+0x15d/0x400
>>>  [<ffffffff8109213d>] ? trace_hardirqs_on+0xd/0x10
>>>  [<ffffffff8105d810>] ? rescuer_thread+0x210/0x210
>>>  [<ffffffff81062bd6>] kthread+0xd6/0xe0
>>>  [<ffffffff8155a18b>] ? _raw_spin_unlock_irq+0x2b/0x50
>>>  [<ffffffff81062b00>] ? __init_kthread_worker+0x70/0x70
>>>  [<ffffffff8155ae6c>] ret_from_fork+0x7c/0xb0
>>>  [<ffffffff81062b00>] ? __init_kthread_worker+0x70/0x70
>>>
>>
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