Re: Upcoming merge window

[Jens Axboe <axboe@kernel.dk>]

On 12/17/18 4:27 PM, Jens Axboe wrote:
> On 12/17/18 4:16 PM, Bart Van Assche wrote:
>> On Mon, 2018-12-17 at 11:28 -0700, Jens Axboe wrote:
>>> As I'm sure you're all aware, the merge window is coming up. This time
>>> it happens to coincide with that is a holiday for most. My plan is to
>>> send in an EARLY pull request to Linus, Thursday at the latest. If you're
>>> sitting on anything that should go in with the initial merge, then I need
>>> to have it ASAP.
>>>
>>> I'll do a later pull about a week in with things that were missed, but
>>> I'm really hoping to make that fixes only. Any driver updates etc should
>>> go in now.
>>
>> Hi Jens,
>>
>> If I run blktests/srp/002 against Linus' master branch then that test passes,
>> no matter how many times I run that test. If I run that test against your
>> for-next branch however (commit 6a252f2772c0) then that test hangs. The output
>> of my list-pending-block-requests script is as follows when the hang occurs:
> 
> Ugh, I'll try and run that here again, that test is unfortunately such a pain
> to run and requires me to manually install multipath libs (and remember to
> uninstall before rebooting, or udev fails?).
> 
> I'll take a look!

Looks like what Ming was talking about. CC'ing Ming and Mike. Lots of
kworkers are stuck like this:

[  252.310187] kworker/2:19    D14072  8147      2 0x80000000
[  252.316803] Workqueue: dio/dm-2 dio_aio_complete_work
[  252.322925] Call Trace:
[  252.326137]  ? __schedule+0x231/0x5f0
[  252.330703]  schedule+0x2a/0x80
[  252.334689]  rwsem_down_write_failed+0x204/0x320
[  252.340330]  ? generic_make_request_checks+0x55/0x370
[  252.346542]  ? call_rwsem_down_write_failed+0x13/0x20
[  252.352669]  call_rwsem_down_write_failed+0x13/0x20
[  252.358601]  down_write+0x1b/0x30
[  252.362781]  __generic_file_fsync+0x3e/0xb0
[  252.367933]  ext4_sync_file+0xcc/0x2e0
[  252.372599]  dio_complete+0x1c4/0x210
[  252.377168]  process_one_work+0x1cb/0x350
[  252.382915]  worker_thread+0x28/0x3c0
[  252.387482]  ? process_one_work+0x350/0x350
[  252.392632]  kthread+0x107/0x120
[  252.396717]  ? kthread_park+0x80/0x80
[  252.401285]  ret_from_fork+0x1f/0x30

Where did this regression come from? This was passing just fine
recently.

-- 
Jens Axboe