Re: [PATCH] fio: fix hangs due to iodepth_low

[Jens Axboe <axboe@kernel.dk>]

On 09/04/2014 01:42 PM, Elliott, Robert (Server Storage) wrote:
> 
> 
>> -----Original Message-----
>> From: Jens Axboe [mailto:axboe@kernel.dk]
>> Sent: Thursday, 04 September, 2014 9:39 AM
>> To: Elliott, Robert (Server Storage); fio@vger.kernel.org;
>> scameron@beardog.cce.hp.com
>> Subject: Re: [PATCH] fio: fix hangs due to iodepth_low
>>
>> On 09/04/2014 08:27 AM, Elliott, Robert (Server Storage) wrote:
>>>>> should be:
>>>>>
>>>>>      if (min_events > td->cur_depth)
>>>>>          min_events = td->cur_depth;
>>>>>
>>>>> and we should probably put this logic in io_u_queued_complete(),
>> I
>>>> think
>>>>> that would be a safer alternative instead of near the callers.
>>>
>>> io_u_quisce, which calls io_u_queued_complete with an argument
>>> of 1, includes this comment:
>>>          * and cur_depth is meaningless for sync engines.
>>>
>>> If that is invoked during sync traffic too, then putting this
>>> change inside io_u_queued_complete might not work right.
>>
>> It's good enough for this use case. And it doesn't really matter if
>> it's
>> near the caller or in the function from this point of view, since
>> there
>> will be nothing (0) to complete for sync engines. By their very
>> nature,
>> they have nothing pending at that point. So I think the patch is fine
>> as
>> I sent out.
> 
> I ran this version through similar tests and it works as well.

Great thanks Rob, I committed that fix.

-- 
Jens Axboe