[PATCH 2/2] blk-stat: add a poll_size value to the request_queue struct

[Jens Axboe]

On 03/28/2017 01:38 PM, Stephen  Bates wrote:
>>>
>>>  In order to bucket IO for the polling algorithm we use a sysfs entry
>>>  to set the filter value. It is signed and we will use that as follows:
>>>
>>>   0   : No filtering. All IO are considered in stat generation
>>>   > 0 : Filtering based on IO of exactly this size only.
>>>   < 0 : Filtering based on IO less than or equal to -1 time this value.>
>>
>> I'd say that this is a fairly non-trivial semantic meanning to this...
>>
>> Is there any use for the size exact match filter? If not then
>> I suggest we always make it (<=) in its semantics...
> 
> Thanks for the review Sagi. I’d be OK going with <=0 as the exact
> match would normally be for minimal IO sizes (where <= and = are the
> same thing). I will see what other feedback I get and aim to do a
> respin soon…

No tunables for this, please. There's absolutely no reason why we should
need it.

-- 
Jens Axboe