On Tue, Aug 23, 2016 at 11:31:08AM +0200, Thomas Monjalon wrote:
> 2016-08-23 16:10, Yuanhan Liu:
> > One thing worth noting while using Tx zero copy is the nb_tx_desc has
> > to be small enough so that the eth driver will hit the mbuf free
> > threshold easily and thus free mbuf more frequently.
> >
> > The reason behind that is, when Tx zero copy is enabled, guest Tx used
> > vring will be updated only when corresponding mbuf is freed. If mbuf is
> > not freed frequently, the guest Tx vring could be starved.
>
> I think you should explain this behaviour in the doc of the vhost flag.
Agreed. Will do it in v2.
--yliu
