[dm-devel] [PATCH 4/7] dm mpath: remove process_queued_ios()
Junichi Nomura
j-nomura at ce.jp.nec.com
Wed Feb 12 02:37:42 UTC 2014
On 02/10/14 22:30, Mike Snitzer wrote:
> On Tue, Feb 04 2014 at 6:31am -0500,
> Hannes Reinecke <hare at suse.de> wrote:
>
>> On 02/04/2014 12:26 PM, Junichi Nomura wrote:
>>> On 02/04/14 19:54, Hannes Reinecke wrote:
>>>> We only need to take care to add a small delay when calling
>>>> __pg_init_all_paths() to move processing off to a workqueue; otherwise
>>>> pg_init_done() might end up calling scsi_dh_activate() directly, which
>>>> might use non-atomic memory allocations or issue I/O.
>>>
>>> Hi Hannes,
>>>
>>> could you tell me how "might end up calling scsi_dh_active()" happens?
>>>
>>> queue_delayed_work()
>>> queue_delayed_work_on()
>>> __queue_delayed_work()
>>> if (!delay)
>>> __queue_work()
>>> get_work_pool()
>>> insert_work()
>>> set_work_pwq()
>>> get_pwq()
>>> if (__need_more_worker())
>>> wake_up_worker()
>>>
>>> queue_work() doesn't execute the work itself.
>>>
>>> What am I missing?
>>>
>> As mentioned, I stumbled across the same issue when developing the
>> asynchronous SCSI aborts. I'll see to have it recreated with this
>> patchset.
>
> Just to verify, this seems to be the only outstanding question for this
> patchset?
Hi Mike, Hannes,
Yes, this is the only remaining question from me.
For other parts of this patch and patchset, issues I pointed were solved.
--
Jun'ichi Nomura, NEC Corporation
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