I can not see that code. Can you point out where is it? Thanks
On Mon, Sep 21, 2015 at 11:41 PM, Stephen Hemminger < stephen at networkplumber.org> wrote: > On Fri, 18 Sep 2015 11:33:36 +0100 > Alejandro Lucero <alejandro.lucero at netronome.com> wrote: > > > I have seen the API definition says nothing about accuracy but some PMD > > implementations sacrifice accuracy for the sake of performance. If I'm > not > > understanding the code wrongly i40e and ixgbe check DD bit just for the > > first descriptor in a group of 4, and they take all of them as used if > the > > first descriptor is used. > > > > By other hand, they do a "heavy" calculation when the descriptor ring > wraps > > which does not make sense (to me) if same performance goal is used. > > > > There are PMDs not supporting this option and I can not see any app or > > example using it so I do not know how important is this function, its > > accuracy and its performance impact. Can someone comment on this? > > > > Thanks > > I have version of this for virtio/vmxnet3 > It is useful when using the interrupt control mode. >