> -----Original Message----- > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Adrien Mazarguil > Sent: Monday, November 13, 2017 10:39 AM > To: Ilya Matveychikov <matvejchi...@gmail.com> > Cc: dev@dpdk.org > Subject: Re: [dpdk-dev] A question about (poor) rte_ethdev internal rx/tx > callbacks design > > On Sat, Nov 11, 2017 at 09:18:45PM +0400, Ilya Matveychikov wrote: > > Folks, > > > > Are you serious with it: > > > > typedef uint16_t (*eth_rx_burst_t)(void *rxq, > > struct rte_mbuf **rx_pkts, > > uint16_t nb_pkts); > > typedef uint16_t (*eth_tx_burst_t)(void *txq, > > struct rte_mbuf **tx_pkts, > > uint16_t nb_pkts); > > > > I’m not surprised that every PMD stores port_id in every and each queue as > > having just the queue as an argument doesn’t allow to get the > device. So the question is - why not to use something like: > > > > typedef uint16_t (*eth_rx_burst_t)(void *dev, uint16_t queue_id, > > struct rte_mbuf **rx_pkts, > > uint16_t nb_pkts); > > typedef uint16_t (*eth_tx_burst_t)(void *dev, uint16_t queue_id, > > struct rte_mbuf **tx_pkts, > > uint16_t nb_pkts); > > I assume it's since the rte_eth_[rt]x_burst() wrappers already pay the price > for that indirection, doing it twice would be redundant. > > Basically the cost of storing a back-pointer to dev or a queue index in each > Rx/Tx queue structure is minor compared to saving a couple of CPU cycles > wherever we can.
For many PMDs we don't need that pointer at all to do RX/TX - information stored inside the queue is sufficient. Konstantin > > I'm not saying its the only solution nor the right approach, it's only one > possible explanation for this API. > > -- > Adrien Mazarguil > 6WIND
