Hi Thomas,
> -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > Sent: Thursday, June 23, 2016 8:22 PM > To: Lu, Wenzhuo > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v3] ethdev: fix DCB config issue on ixgbe > > 2016-06-23 01:04, Lu, Wenzhuo: > > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > > > 2016-05-06 05:33, Wenzhuo Lu: > > > > +int > > > > +rte_eth_dev_mq_mode_set(uint8_t port_id, > > > > + enum rte_eth_rx_mq_mode rx_mq_mode, > > > > + enum rte_eth_tx_mq_mode tx_mq_mode); > > > > > > I've really tried to think about it and I think it is more or less a hack. > > > First, it is not explained in the doc when we should use > > > rte_eth_dev_mq_mode_set() instead of a simple call to > rte_eth_dev_configure(). > > > Second, I don't understand why having a function which configures > > > the "multiqueue modes" without configuring properly RSS/VMDq/DCB. > > > Last, it is said that rte_eth_dev_configure() "must be invoked first > > > before any other function in the Ethernet API". > > Sorry, didn't notice this announcement. > > > > > My opinion is that the primary goal of rte_eth_dev_configure() was > > > "Embedding all configuration information in a single data structure" > > > but it is currently configuring only speed and some flow steering > > > (only RSS, VMDq, DCB and flow director). > > > This bug and the state of the ethdev API clearly shows that we must > > > have one function per feature (or group of features) and drop > rte_eth_dev_configure(). > > > > > > You can argue it is a just a personal feeling and this comment comes > > > late, but I promise it is not easy to give a negative opinion because of > > > design > perspective. > > > I strongly feel we must stop workarounding the ethdev API issues and > > > start really fixing it. > > > > > > Hope you understand and agree to work on a new API. > > I have the same feeling with you. There's some problem with > rte_eth_dev_configure. So this patch is a workaround more than a real fix. > > But the problem is this API has already been used. What I think is could we > > take > this workaround as a first step. It need not ask the APP to change too much. > > Then we can discuss how could we rework on a new API or APIs. We all > > know the change in rte layer is not easy and need to be very careful > > :) > > We probably need more opinions. > I think it is not a good idea to introduce a new API only to workaround > another > one and keep confusion in place. > A similar approach which looks better is to introduce a new API which will > partly > replace the old one and will remain a good one when the old API will be > completely removed. > In other words, we should introduce a good API for flow steering as soon as > possible and deprecate rte_eth_dev_configure(). I think you're right. The workaround can make things confusing. Better to introduce a new API to replace rte_eth_dev_configure.
