[dpdk-dev] [PATCH v6 4/4] latencystats: added new library for latency stats

Remy Horton remy.horton at intel.com
Thu Jan 12 15:44:29 CET 2017


On 12/01/2017 13:41, Thomas Monjalon wrote:
> 2017-01-12 00:03, Remy Horton:
>> Add a library designed to calculate latency statistics and report them
>> to the application when queried. The library measures minimum, average and
>> maximum latencies, and jitter in nano seconds. The current implementation
>> supports global latency stats, i.e. per application stats.
>
> Is it specific to ethdev ports?

No (or at least not at the moment).


>> Added new field to mbuf struct to mark the packet arrival time on Rx.
>
> There was another patch adding a timestamp in mbuf:
> 	http://dpdk.org/ml/archives/dev/2016-October/048809.html

Will look into it. Since time is tight will have internal discussion 
whether latency will make it into 17.02..


>> APIs:
>>
>> * Added APIs to initialize and un initialize latency stats
>>   calculation.
>> * Added API to retrieve latency stats names and values.
>
> Why bitrate and latencies are separate libs?

They were developed independently by different people in response to 
seperate requirements.

Reshma went on extended leave, so I took over the latency patch at the 
last moment when development was complete. Aside from rebase-related 
fixups and one printf change it is the last version of her seperate 
patch included verbatim.

..Remy


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