[dm-devel] [PATCH v8 05/11] null_blk: allow non power of 2 zoned devices

[Pankaj Raghav]

On 2022-07-27 23:59, Chaitanya Kulkarni wrote:
>> Sequential Write:
>>
>> x-----------------x---------------------------------x---------------------------------x
>> |     IOdepth     |            8                    |            16                   |
>> x-----------------x---------------------------------x---------------------------------x
>> |                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
>> x-----------------x---------------------------------x---------------------------------x
>> | Without patch   |  578     |  2257    |   12.80   |  576     |  2248    |   25.78   |
>> x-----------------x---------------------------------x---------------------------------x
>> |  With patch     |  581     |  2268    |   12.74   |  576     |  2248    |   25.85   |
>> x-----------------x---------------------------------x---------------------------------x
>>
>> Sequential read:
>>
>> x-----------------x---------------------------------x---------------------------------x
>> | IOdepth         |            8                    |            16                   |
>> x-----------------x---------------------------------x---------------------------------x
>> |                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
>> x-----------------x---------------------------------x---------------------------------x
>> | Without patch   |  667     |  2605    |   11.79   |  675     |  2637    |   23.49   |
>> x-----------------x---------------------------------x---------------------------------x
>> |  With patch     |  667     |  2605    |   11.79   |  675     |  2638    |   23.48   |
>> x-----------------x---------------------------------x---------------------------------x
>>
>> Random read:
>>
>> x-----------------x---------------------------------x---------------------------------x
>> | IOdepth         |            8                    |            16                   |
>> x-----------------x---------------------------------x---------------------------------x
>> |                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
>> x-----------------x---------------------------------x---------------------------------x
>> | Without patch   |  522     |  2038    |   15.05   |  514     |  2006    |   30.87   |
>> x-----------------x---------------------------------x---------------------------------x
>> |  With patch     |  522     |  2039    |   15.04   |  523     |  2042    |   30.33   |
>> x-----------------x---------------------------------x---------------------------------x
>>
>> Minor variations are noticed in Sequential write with io depth 8 and
>> in random read with io depth 16. But overall no noticeable differences
>> were noticed
> 
> minor variations in with aspect of the performance ?
> are these documented somewhere ?
> 
The table above documents those minor variations in performance.
> move the large table of performance numbers to the cover letter it looks 
> ugly in the git log...
> 
I could do that.
>