[PATCH v2] mempool: fix get objects from mempool with cache

[Andrew Rybchenko]

On 10/4/22 18:13, Morten Brørup wrote:
> @Aaron, do you have any insights or comments to my curiosity below?
> 
>> From: Andrew Rybchenko [mailto:andrew.rybchenko at oktetlabs.ru]
>> Sent: Tuesday, 4 October 2022 14.58
>>
>> Hi Morten,
>>
>> In general I agree that the fix is required.
>> In sent v3 I'm trying to make it a bit better from my point of
>> view. See few notes below.
> 
> I stand by my review and accept of v3 - this message is not intended to change that! I'm just curious...
> 
> I wonder how accurate the automated performance tests ([v2], [v3]) are, and if they are comparable between February and October?
> 
> [v2]: http://mails.dpdk.org/archives/test-report/2022-February/256462.html
> [v3]: http://mails.dpdk.org/archives/test-report/2022-October/311526.html
> 
> 
> Ubuntu 20.04
> Kernel: 4.15.0-generic
> Compiler: gcc 7.4
> NIC: Intel Corporation Ethernet Converged Network Adapter XL710-QDA2 40000 Mbps
> Target: x86_64-native-linuxapp-gcc
> Fail/Total: 0/4
> 
> Detail performance results:
> ** V2 **:
> +----------+-------------+---------+------------+------------------------------+
> | num_cpus | num_threads | txd/rxd | frame_size |  throughput difference from  |
> |          |             |         |            |           expected           |
> +==========+=============+=========+============+==============================+
> | 1        | 2           | 512     | 64         | 0.5%                         |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 2           | 2048    | 64         | -1.5%                        |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 1           | 512     | 64         | 4.3%                         |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 1           | 2048    | 64         | 10.9%                        |
> +----------+-------------+---------+------------+------------------------------+
> 
> ** V3 **:
> +----------+-------------+---------+------------+------------------------------+
> | num_cpus | num_threads | txd/rxd | frame_size |  throughput difference from  |
> |          |             |         |            |           expected           |
> +==========+=============+=========+============+==============================+
> | 1        | 2           | 512     | 64         | -0.7%                        |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 2           | 2048    | 64         | -2.3%                        |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 1           | 512     | 64         | 0.5%                         |
> +----------+-------------+---------+------------+------------------------------+
> | 1        | 1           | 2048    | 64         | 7.9%                         |
> +----------+-------------+---------+------------+------------------------------+
> 

Very interesting, may be it make sense to sent your patch and
mine once again to check current figures and results stability.