> -----Original Message----- > From: Konstantin Ananyev <konstantin.anan...@huawei.com> > Sent: Tuesday, June 6, 2023 3:18 PM > To: Feifei Wang <feifei.wa...@arm.com>; Константин Ананьев > <konstantin.v.anan...@yandex.ru>; Yuying Zhang > <yuying.zh...@intel.com>; Beilei Xing <beilei.x...@intel.com> > Cc: dev@dpdk.org; nd <n...@arm.com>; Honnappa Nagarahalli > <honnappa.nagaraha...@arm.com>; Ruifeng Wang > <ruifeng.w...@arm.com>; nd <n...@arm.com> > Subject: RE: [PATCH v6 2/4] net/i40e: implement mbufs recycle mode > > > > > Define specific function implementation for i40e driver. > > Currently, mbufs recycle mode can support 128bit vector path and avx2 > > path. And can be enabled both in fast free and no fast free mode. > > > > Suggested-by: Honnappa Nagarahalli > > <mailto:honnappa.nagaraha...@arm.com> > > Signed-off-by: Feifei Wang <mailto:feifei.wa...@arm.com> > > Reviewed-by: Ruifeng Wang <mailto:ruifeng.w...@arm.com> > > Reviewed-by: Honnappa Nagarahalli > > <mailto:honnappa.nagaraha...@arm.com> > > --- > > drivers/net/i40e/i40e_ethdev.c | 1 + > > drivers/net/i40e/i40e_ethdev.h | 2 + > > .../net/i40e/i40e_recycle_mbufs_vec_common.c | 140 > ++++++++++++++++++ > > drivers/net/i40e/i40e_rxtx.c | 32 ++++ drivers/net/i40e/i40e_rxtx.h | > > 4 + drivers/net/i40e/meson.build | 2 + > > 6 files changed, 181 insertions(+) > > create mode 100644 drivers/net/i40e/i40e_recycle_mbufs_vec_common.c > > > > diff --git a/drivers/net/i40e/i40e_ethdev.c > > b/drivers/net/i40e/i40e_ethdev.c index f9d8f9791f..d4eecd16cf 100644 > > --- a/drivers/net/i40e/i40e_ethdev.c > > +++ b/drivers/net/i40e/i40e_ethdev.c > > @@ -496,6 +496,7 @@ static const struct eth_dev_ops i40e_eth_dev_ops = > { > > .flow_ops_get = i40e_dev_flow_ops_get, > > .rxq_info_get = i40e_rxq_info_get, > > .txq_info_get = i40e_txq_info_get, > > + .recycle_rxq_info_get = i40e_recycle_rxq_info_get, > > .rx_burst_mode_get = i40e_rx_burst_mode_get, > > .tx_burst_mode_get = i40e_tx_burst_mode_get, > > .timesync_enable = i40e_timesync_enable, diff --git > > a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h > > index 9b806d130e..b5b2d6cf2b 100644 > > --- a/drivers/net/i40e/i40e_ethdev.h > > +++ b/drivers/net/i40e/i40e_ethdev.h > > @@ -1355,6 +1355,8 @@ void i40e_rxq_info_get(struct rte_eth_dev *dev, > uint16_t queue_id, > > struct rte_eth_rxq_info *qinfo); void > > i40e_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id, > > struct rte_eth_txq_info *qinfo); > > +void i40e_recycle_rxq_info_get(struct rte_eth_dev *dev, uint16_t > > +queue_id, struct rte_eth_recycle_rxq_info *recycle_rxq_info); > > int i40e_rx_burst_mode_get(struct rte_eth_dev *dev, uint16_t queue_id, > > struct rte_eth_burst_mode *mode); int > > i40e_tx_burst_mode_get(struct rte_eth_dev *dev, uint16_t queue_id, > > diff --git a/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c > > b/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c > > new file mode 100644 > > index 0000000000..08d708fd7d > > --- /dev/null > > +++ b/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c > > @@ -0,0 +1,140 @@ > > +/* SPDX-License-Identifier: BSD-3-Clause > > + * Copyright (c) 2023 Arm Limited. > > + */ > > + > > +#include <stdint.h> > > +#include <ethdev_driver.h> > > + > > +#include "base/i40e_prototype.h" > > +#include "base/i40e_type.h" > > +#include "i40e_ethdev.h" > > +#include "i40e_rxtx.h" > > + > > +#pragma GCC diagnostic ignored "-Wcast-qual" > > + > > +void > > +i40e_recycle_rx_descriptors_refill_vec(void *rx_queue, uint16_t > > +nb_mbufs) { struct i40e_rx_queue *rxq = rx_queue; struct > > +i40e_rx_entry *rxep; volatile union i40e_rx_desc *rxdp; uint16_t > > +rx_id; uint64_t paddr; uint64_t dma_addr; uint16_t i; > > + > > + rxdp = rxq->rx_ring + rxq->rxrearm_start; rxep = > > + &rxq->sw_ring[rxq->rxrearm_start]; > > + > > + for (i = 0; i < nb_mbufs; i++) { > > + /* Initialize rxdp descs. */ > > + paddr = (rxep[i].mbuf)->buf_iova + RTE_PKTMBUF_HEADROOM; > dma_addr = > > + rte_cpu_to_le_64(paddr); > > + /* flush desc with pa dma_addr */ > > + rxdp[i].read.hdr_addr = 0; > > + rxdp[i].read.pkt_addr = dma_addr; > > + } > > + > > + /* Update the descriptor initializer index */ > > + rxq->rxrearm_start += nb_mbufs; > > + rx_id = rxq->rxrearm_start - 1; > > + > > + if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) { > > + rxq->rxrearm_start = 0; > > + rx_id = rxq->nb_rx_desc - 1; > > + } > > + > > + rxq->rxrearm_nb -= nb_mbufs; > > + > > + rte_io_wmb(); > > + /* Update the tail pointer on the NIC */ > > +I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id); } > > + > > +uint16_t > > +i40e_recycle_tx_mbufs_reuse_vec(void *tx_queue, struct > > +rte_eth_recycle_rxq_info *recycle_rxq_info) { struct i40e_tx_queue > > +*txq = tx_queue; struct i40e_tx_entry *txep; struct rte_mbuf > > +**rxep; struct rte_mbuf *m[RTE_I40E_TX_MAX_FREE_BUF_SZ]; int i, j, > > +n; uint16_t avail = 0; uint16_t mbuf_ring_size = > > +recycle_rxq_info->mbuf_ring_size; > > + uint16_t mask = recycle_rxq_info->mbuf_ring_size - 1; uint16_t > > +refill_requirement = recycle_rxq_info->refill_requirement; > > + uint16_t refill_head = *recycle_rxq_info->refill_head; uint16_t > > +receive_tail = *recycle_rxq_info->receive_tail; > > + > > + /* Get available recycling Rx buffers. */ avail = (mbuf_ring_size - > > + (refill_head - receive_tail)) & mask; > > + > > + /* Check Tx free thresh and Rx available space. */ if > > + (txq->nb_tx_free > txq->tx_free_thresh || avail <= > > + txq->tx_rs_thresh) return 0; > > + > > + /* check DD bits on threshold descriptor */ if > > + ((txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz & > > + rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) != > > + rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)) > > + return 0; > > + > > + n = txq->tx_rs_thresh; > > + > > + /* Mbufs recycle mode can only support no ring buffer wrapping around. > > + * Two case for this: > > + * > > + * case 1: The refill head of Rx buffer ring needs to be aligned with > > + * mbuf ring size. In this case, the number of Tx freeing buffers > > + * should be equal to refill_requirement. > > + * > > + * case 2: The refill head of Rx ring buffer does not need to be > > + aligned > > + * with mbuf ring size. In this case, the update of refill head can > > + not > > + * exceed the Rx mbuf ring size. > > + */ > > + if (refill_requirement != n || > > + (!refill_requirement && (refill_head + n > mbuf_ring_size))) return > > + 0; > > + > > + /* First buffer to free from S/W ring is at index > > + * tx_next_dd - (tx_rs_thresh-1). > > + */ > > + txep = &txq->sw_ring[txq->tx_next_dd - (n - 1)]; rxep = > > + recycle_rxq_info->mbuf_ring; rxep += refill_head; > > + > > + if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) { > > + /* Directly put mbufs from Tx to Rx. */ for (i = 0; i < n; i++, > > + rxep++, txep++) *rxep = txep[0].mbuf; } else { for (i = 0, j = 0; i > > + < n; i++) { > > + /* Avoid txq contains buffers from expected mempool. */ if > > + (unlikely(recycle_rxq_info->mp != txep[i].mbuf->pool)) return 0; > > I don't think that it is possible to simply return 0 here: > > we might already have some mbufs inside rxep[], so we probably need to > > return that number (j). > > > > No, here is just pre-free, not actually put mbufs into rxeq. > > I understand that. > What I am saying: after you call pktmbuf_prefree_seg(mbuf), you can’t keep it > in the txq anymore. > You have either to put it into rxep[], or back into mempool. > Also txq state (nb_tx_free, etc.) need to be updated. > > > After run out of the loop, we call rte_memcpy to actually copy mbufs > > into rxep. > > + > > + m[j] = rte_pktmbuf_prefree_seg(txep[i].mbuf); > > + > > + /* In case 1, each of Tx buffers should be the > > + * last reference. > > + */ > > + if (unlikely(m[j] == NULL && refill_requirement)) return 0; > > > > same here, we can't simply return 0, it will introduce mbuf leakage. > > + /* In case 2, the number of valid Tx free > > + * buffers should be recorded. > > + */ > > + j++; > > + } > > + rte_memcpy(rxep, m, sizeof(void *) * j); > > Wonder why do you need intermediate buffer for released mbufs? > > Why can't just: > > ... > > m = rte_pktmbuf_prefree_seg(txep[i].mbuf); > > ... > > rxep[j++] = m; > > ? > > Might save you few extra cycles. > > Sometimes ‘rte_pktmbuf_prefree_seg’ can return NULL due to > > mbuf->refcnt > 1. So we should firstly ensure all ‘m’ are valid and > > then copy them into rxep. > > I understand that, but you can check is it NULL or not. For i40e rxq, it must rearm ' RTE_I40E_RXQ_REARM_THRESH ' pkts once a time based on its ring wrapping mechanism.
For i40e txq, it must free ' txq->tx_rs_thresh' pkts once a time. So we need firstly ensure all tx free mbufs are valid, and then copy these into rxq. If not enough valid mbufs, it will break rxq's ring wrapping mechanism. > > > + } > > + > > + /* Update counters for Tx. */ > > + txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + txq->tx_rs_thresh); > > + txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + txq->tx_rs_thresh); > > + if (txq->tx_next_dd >= txq->nb_tx_desc) > > + txq->tx_next_dd = (uint16_t)(txq->tx_rs_thresh - 1); > > + > > + return n; > > +}
