On 04/07/2017 06:11 AM, Stephen Bates wrote:
> On 2017-04-05, 7:14 PM, "Jens Axboe" <[email protected]> wrote:
>
>> Why not just have 8 buckets, and make it:
>>
>> bucket = ddir + ilog2(bytes) - 9;
>>
>> and cap it at MAX_BUCKET (8) and put all those above into the top
>> bucket.
>
> Thanks. However, that equation does not differentiate between
> direction and size. Instead we can use
>
> bucket = ddir + 2*(ilog2(bytes) - 9);
It would be cleaner to just embed the fact that we have 2 sets of
identical buckets, and return
bucket = ilog2(bytes) - 9;
and have poll_stat be indexed by:
->poll_stat[ddir][bucket];
instead.
--
Jens Axboe
