[dpdk-dev] [PATCH] doc: announce ABI change on ethdev

[Shahaf Shuler]

Tuesday, May 9, 2017 4:49 PM, Ferruh Yigit:
> On 5/1/2017 7:58 AM, Shahaf Shuler wrote:
> 
> I understand the consistency part, but why PMD performs better when Tx
> offload disabled?
> 

Well Adrien pretty much summarized it [1].

Tx offload consumes cycles, for examples checksum or TSO.
Since those offloads are enabled by default, the application will need to pay for them, even if they are not used.
True, it is possible to disable them, however when new offloads are introduced the application will need to be constantly modified in order to disable the new ones. 

A better approach will be to disable all the Tx offload by default, and enable them according to the application needs. 
This will enable to the PMD to provide the Tx burst function which suits the most to the application specific needs, with no extra overhead.

[1] http://dpdk.org/ml/archives/dev/2017-May/065509.html