On Thu, 22 Oct 2015 20:09:50 +0800 Huawei Xie <huawei.xie at intel.com> wrote:
> Changes in v4: > - move virtio_xmit_cleanup ahead to free descriptors earlier > > Changes in v3: > - Remove return at the end of void function > - Remove always_inline attribute for virtio_xmit_cleanup > bulk free of mbufs when clean used ring. > shift operation of idx could be saved if vq_free_cnt means > free slots rather than free descriptors. > > TODO: rearrange vq data structure, pack the stats var together so that we > could use one vec instruction to update all of them. > > Signed-off-by: Huawei Xie <huawei.xie at intel.com> > --- > drivers/net/virtio/virtio_ethdev.h | 3 ++ > drivers/net/virtio/virtio_rxtx_simple.c | 93 > +++++++++++++++++++++++++++++++++ > 2 files changed, 96 insertions(+) > > diff --git a/drivers/net/virtio/virtio_ethdev.h > b/drivers/net/virtio/virtio_ethdev.h > index d7797ab..ae2d47d 100644 > --- a/drivers/net/virtio/virtio_ethdev.h > +++ b/drivers/net/virtio/virtio_ethdev.h > @@ -111,6 +111,9 @@ uint16_t virtio_xmit_pkts(void *tx_queue, struct rte_mbuf > **tx_pkts, > uint16_t virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts, > uint16_t nb_pkts); > > +uint16_t virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts, > + uint16_t nb_pkts); > + > /* > * The VIRTIO_NET_F_GUEST_TSO[46] features permit the host to send us > * frames larger than 1514 bytes. We do not yet support software LRO > diff --git a/drivers/net/virtio/virtio_rxtx_simple.c > b/drivers/net/virtio/virtio_rxtx_simple.c > index ef17562..79b4f7f 100644 > --- a/drivers/net/virtio/virtio_rxtx_simple.c > +++ b/drivers/net/virtio/virtio_rxtx_simple.c > @@ -288,6 +288,99 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf > **rx_pkts, > return nb_pkts_received; > } > > +#define VIRTIO_TX_FREE_THRESH 32 > +#define VIRTIO_TX_MAX_FREE_BUF_SZ 32 > +#define VIRTIO_TX_FREE_NR 32 > +/* TODO: vq->tx_free_cnt could mean num of free slots so we could avoid > shift */ > +static inline void > +virtio_xmit_cleanup(struct virtqueue *vq) > +{ > + uint16_t i, desc_idx; > + int nb_free = 0; > + struct rte_mbuf *m, *free[VIRTIO_TX_MAX_FREE_BUF_SZ]; > + > + desc_idx = (uint16_t)(vq->vq_used_cons_idx & > + ((vq->vq_nentries >> 1) - 1)); > + free[0] = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie; > + nb_free = 1; > + > + for (i = 1; i < VIRTIO_TX_FREE_NR; i++) { > + m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie; > + if (likely(m->pool == free[0]->pool)) > + free[nb_free++] = m; > + else { > + rte_mempool_put_bulk(free[0]->pool, (void **)free, > + nb_free); > + free[0] = m; > + nb_free = 1; > + } > + } > + > + rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free); > + vq->vq_used_cons_idx += VIRTIO_TX_FREE_NR; > + vq->vq_free_cnt += (VIRTIO_TX_FREE_NR << 1); > +} I think you need to handle refcount, here is a similar patch for ixgbe. Subject: ixgbe: speed up transmit Coalesce transmit buffers and put them back into the pool in one burst. Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c @@ -120,12 +120,16 @@ rte_rxmbuf_alloc(struct rte_mempool *mp) * Check for descriptors with their DD bit set and free mbufs. * Return the total number of buffers freed. */ +#define TX_FREE_BULK 32 + static inline int __attribute__((always_inline)) ixgbe_tx_free_bufs(struct ixgbe_tx_queue *txq) { struct ixgbe_tx_entry *txep; uint32_t status; - int i; + int i, n = 0; + struct rte_mempool *txpool = NULL; + struct rte_mbuf *free_list[TX_FREE_BULK]; /* check DD bit on threshold descriptor */ status = txq->tx_ring[txq->tx_next_dd].wb.status; @@ -138,20 +142,26 @@ ixgbe_tx_free_bufs(struct ixgbe_tx_queue */ txep = &(txq->sw_ring[txq->tx_next_dd - (txq->tx_rs_thresh - 1)]); - /* free buffers one at a time */ - if ((txq->txq_flags & (uint32_t)ETH_TXQ_FLAGS_NOREFCOUNT) != 0) { - for (i = 0; i < txq->tx_rs_thresh; ++i, ++txep) { - txep->mbuf->next = NULL; - rte_mempool_put(txep->mbuf->pool, txep->mbuf); - txep->mbuf = NULL; - } - } else { - for (i = 0; i < txq->tx_rs_thresh; ++i, ++txep) { - rte_pktmbuf_free_seg(txep->mbuf); - txep->mbuf = NULL; + for (i = 0; i < txq->tx_rs_thresh; ++i, ++txep) { + struct rte_mbuf *m; + + /* free buffers one at a time */ + m = __rte_pktmbuf_prefree_seg(txep->mbuf); + txep->mbuf = NULL; + + if (n >= TX_FREE_BULK || + (n > 0 && m->pool != txpool)) { + rte_mempool_put_bulk(txpool, (void **)free_list, n); + n = 0; } + + txpool = m->pool; + free_list[n++] = m; } + if (n > 0) + rte_mempool_put_bulk(txpool, (void **)free_list, n); + /* buffers were freed, update counters */ 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);