> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Ananyev, > Konstantin > > > > How can we hide the callbacks since they are used by inline burst > functions. > > > > I probably I owe a better explanation to what I meant in first mail. > > Otherwise it sounds confusing. > > I'll try to write a more detailed one in next few days. > > Actually I gave it another thought over weekend, and might be we can > hide rte_eth_dev_cb even in a simpler way. I'd use eth_rx_burst() as > an example, but the same principle applies to other 'fast' functions. > > 1. Needed changes for PMDs rx_pkt_burst(): > a) change function prototype to accept 'uint16_t port_id' and > 'uint16_t queue_id', > instead of current 'void *'. > b) Each PMD rx_pkt_burst() will have to call rte_eth_rx_epilog() > function at return. > This inline function will do all CB calls for that queue. > > To be more specific, let say we have some PMD: xyz with RX function: > > uint16_t > xyz_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t > nb_pkts) > { > struct xyz_rx_queue *rxq = rx_queue; > uint16_t nb_rx = 0; > > /* do actual stuff here */ > .... > return nb_rx; > } > > It will be transformed to: > > uint16_t > xyz_recv_pkts(uint16_t port_id, uint16_t queue_id, struct rte_mbuf > **rx_pkts, uint16_t nb_pkts) > { > struct xyz_rx_queue *rxq; > uint16_t nb_rx; > > rxq = _rte_eth_rx_prolog(port_id, queue_id); > if (rxq == NULL) > return 0; > nb_rx = _xyz_real_recv_pkts(rxq, rx_pkts, nb_pkts); > return _rte_eth_rx_epilog(port_id, queue_id, rx_pkts, > nb_pkts); > } > > And somewhere in ethdev_private.h: > > static inline void * > _rte_eth_rx_prolog(uint16_t port_id, uint16_t queue_id); > { > struct rte_eth_dev *dev = &rte_eth_devices[port_id]; > > #ifdef RTE_ETHDEV_DEBUG_RX > RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, NULL); > RTE_FUNC_PTR_OR_ERR_RET(*dev->rx_pkt_burst, NULL); > > if (queue_id >= dev->data->nb_rx_queues) { > RTE_ETHDEV_LOG(ERR, "Invalid RX queue_id=%u\n", > queue_id); > return NULL; > } > #endif > return dev->data->rx_queues[queue_id]; > } > > static inline uint16_t > _rte_eth_rx_epilog(uint16_t port_id, uint16_t queue_id, struct rte_mbuf > **rx_pkts, const uint16_t nb_pkts); > { > struct rte_eth_dev *dev = &rte_eth_devices[port_id]; > > #ifdef RTE_ETHDEV_RXTX_CALLBACKS > struct rte_eth_rxtx_callback *cb; > > /* __ATOMIC_RELEASE memory order was used when the > * call back was inserted into the list. > * Since there is a clear dependency between loading > * cb and cb->fn/cb->next, __ATOMIC_ACQUIRE memory order is > * not required. > */ > cb = __atomic_load_n(&dev->post_rx_burst_cbs[queue_id], > __ATOMIC_RELAXED); > > if (unlikely(cb != NULL)) { > do { > nb_rx = cb->fn.rx(port_id, queue_id, rx_pkts, > nb_rx, > nb_pkts, cb->param); > cb = cb->next; > } while (cb != NULL); > } > #endif > > rte_ethdev_trace_rx_burst(port_id, queue_id, (void **)rx_pkts, > nb_rx); > return nb_rx; > }
That would make the compiler inline _rte_eth_rx_epilog() into the driver when compiling the DPDK library. But RTE_ETHDEV_RXTX_CALLBACKS is a definition for the application developer to use when compiling the DPDK application. > > Now, as you said above, in rte_ethdev.h we will keep only a flat array > with pointers to 'fast' functions: > struct { > eth_rx_burst_t rx_pkt_burst > eth_tx_burst_t tx_pkt_burst; > eth_tx_prep_t tx_pkt_prepare; > ..... > } rte_eth_dev_burst[]; > > And rte_eth_rx_burst() will look like: > > static inline uint16_t > rte_eth_rx_burst(uint16_t port_id, uint16_t queue_id, > struct rte_mbuf **rx_pkts, const uint16_t nb_pkts) > { > if (port_id >= RTE_MAX_ETHPORTS) > return 0; > return rte_eth_dev_burst[port_id](port_id, queue_id, rx_pkts, > nb_pkts); > } > > Yes, it will require changes in *all* PMDs, but as I said before the > changes will be a mechanic ones.