Re: [PATCH BUGFIX 0/2] bfq: fix unbalanced decrements causing loss of throughput

From: Jens Axboe
Date: Mon Jan 14 2019 - 08:26:16 EST


On 1/14/19 2:09 AM, Paolo Valente wrote:
>
>
>> Il giorno 7 dic 2018, alle ore 15:40, Jens Axboe <axboe@xxxxxxxxx> ha scritto:
>>
>> On 12/7/18 3:01 AM, Paolo Valente wrote:
>>>
>>>
>>>> Il giorno 7 dic 2018, alle ore 03:23, Jens Axboe <axboe@xxxxxxxxx> ha scritto:
>>>>
>>>> On 12/6/18 11:18 AM, Paolo Valente wrote:
>>>>> Hi Jens,
>>>>> the first patch in this series fixes an error in the decrementing of
>>>>> the counter of the number of groups with pending I/O. This wrong
>>>>> decrement caused loss of throughput or, less likely, of control on
>>>>> I/O. The second patch is a fix of some wrong comments, which somehow
>>>>> contributed to making the above bug more difficult to find.
>>>>
>>>> Are you fine with this going into 4.21? I can't quite tell what your
>>>> intent is. The first patch has a Fixes for something
>>>
>>> yep, that fixes a serious error.
>>>
>>>> that went into
>>>> this series, but then patch 2 is a comment update that would not
>>>> normally be something to be applied at this stage.
>>>>
>>>
>>> and yes, only comments changed by the second one
>>>
>>> May it make sense to apply them in two steps, one in the 4.20 and the other one in the 4.21?
>>
>> I think so, I'll do that.
>
> Hi Jens,
> is the second patch still queued?

That got dropped for some reason, I've applied it now.

--
Jens Axboe