Re: [dpdk-dev] [PATCH 0/6] app/testpmd: add runtime config

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 8/26/2020 11:06 PM, Ferruh Yigit wrote:
> On 8/26/2020 6:07 PM, Dharmik Thakkar wrote:
>>
>>
>>> On Aug 26, 2020, at 11:41 AM, Bruce Richardson <bruce.richardson@intel.com> wrote:
>>>
>>> On Wed, Aug 26, 2020 at 05:33:20PM +0100, Ferruh Yigit wrote:
>>>> On 7/14/2020 10:51 PM, Dharmik Thakkar wrote:
>>>>> Meson build system lacks support for
>>>>> CONFIG_RTE_TEST_PMD_RECORD_CORE_CYCLES and
>>>>> CONFIG_RTE_TEST_PMD_RECORD_BURST_STATS configuration options.
>>>>>
>>>>> One solution is to add these options within meson_options.txt
>>>>>
>>>>> Since adding these as runtime config causes no performance impact,
>>>>
>>>> Hi Dharmik,
>>>>
>>>> These are on the datapath, and even disable there will be additional
>>>> checks, isn't it expected to have some impact?  Did you do any
>>>> measurements for it?
>>
>> Hi Ferruh,
>>
>> In my measurements, I saw a maximum performance degradation of 0.3% for rx and tx throughput (pps)
>> with runtime option (both disabled and enabled cases) when compared to compile time option..
>> There was no difference in cycles per packet measurement.
>> I did these measurements with Mellanox-ConnectX-5 card on N1SDP server with ’set fwd mac retry’ option.
>>
> 
> Thanks Dharmik,
> 
> 0.3% does not look a lot, I also don't get any recognizable drop when the stats
> are disabled (there is a drop (up to %15) when stats are enabled but that is OK).
> And there is a benefit to have the stats runtime configurable.
> 
> This minor drop for runtime configuration looks OK to me, but lets wait a little
> more if there is any strong objection to it, we can proceed afterwards.

There seems no objection to switching runtime configuration.

For series,
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

Series applied to dpdk-next-net/main, thanks.
(doc patches merged to the code while merging.)