From: Marvin Liu Date: Thu, 24 Oct 2019 16:08:31 +0000 (+0800) Subject: vhost: optimize packed ring dequeue X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=31d6c6a5b8208c3b9bec010431d0d005d682dc27;p=dpdk.git vhost: optimize packed ring dequeue Optimize vhost device packed ring dequeue function by splitting batch and single functions. No-chained and direct descriptors will be handled by batch and other will be handled by single as before. Signed-off-by: Marvin Liu Reviewed-by: Maxime Coquelin --- diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 0243573a35..ab6726996b 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -201,68 +201,6 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev, vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE); } -static __rte_always_inline void -flush_shadow_used_ring_packed(struct virtio_net *dev, - struct vhost_virtqueue *vq) -{ - int i; - uint16_t used_idx = vq->last_used_idx; - uint16_t head_idx = vq->last_used_idx; - uint16_t head_flags = 0; - - /* Split loop in two to save memory barriers */ - for (i = 0; i < vq->shadow_used_idx; i++) { - vq->desc_packed[used_idx].id = vq->shadow_used_packed[i].id; - vq->desc_packed[used_idx].len = vq->shadow_used_packed[i].len; - - used_idx += vq->shadow_used_packed[i].count; - if (used_idx >= vq->size) - used_idx -= vq->size; - } - - for (i = 0; i < vq->shadow_used_idx; i++) { - uint16_t flags; - - if (vq->shadow_used_packed[i].len) - flags = VRING_DESC_F_WRITE; - else - flags = 0; - - if (vq->used_wrap_counter) { - flags |= VRING_DESC_F_USED; - flags |= VRING_DESC_F_AVAIL; - } else { - flags &= ~VRING_DESC_F_USED; - flags &= ~VRING_DESC_F_AVAIL; - } - - if (i > 0) { - vq->desc_packed[vq->last_used_idx].flags = flags; - - vhost_log_cache_used_vring(dev, vq, - vq->last_used_idx * - sizeof(struct vring_packed_desc), - sizeof(struct vring_packed_desc)); - } else { - head_idx = vq->last_used_idx; - head_flags = flags; - } - - vq_inc_last_used_packed(vq, vq->shadow_used_packed[i].count); - } - - __atomic_store_n(&vq->desc_packed[head_idx].flags, head_flags, - __ATOMIC_RELEASE); - - vhost_log_cache_used_vring(dev, vq, - head_idx * - sizeof(struct vring_packed_desc), - sizeof(struct vring_packed_desc)); - - vq->shadow_used_idx = 0; - vhost_log_cache_sync(dev, vq); -} - static __rte_always_inline void vhost_shadow_dequeue_batch_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, @@ -335,17 +273,6 @@ vhost_shadow_dequeue_single_packed(struct vhost_virtqueue *vq, vq_inc_last_used_packed(vq, count); } -static __rte_always_inline void -update_shadow_used_ring_packed(struct vhost_virtqueue *vq, - uint16_t desc_idx, uint32_t len, uint16_t count) -{ - uint16_t i = vq->shadow_used_idx++; - - vq->shadow_used_packed[i].id = desc_idx; - vq->shadow_used_packed[i].len = len; - vq->shadow_used_packed[i].count = count; -} - static inline void do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq) { @@ -403,7 +330,7 @@ vhost_shadow_enqueue_single_packed(struct virtio_net *dev, } } -static __rte_unused void +static __rte_always_inline void vhost_flush_dequeue_packed(struct virtio_net *dev, struct vhost_virtqueue *vq) { @@ -1893,7 +1820,7 @@ free_buf: return -1; } -static __rte_unused int +static __rte_always_inline int virtio_dev_tx_batch_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool, @@ -1961,7 +1888,7 @@ vhost_dequeue_single_packed(struct virtio_net *dev, return 0; } -static __rte_unused int +static __rte_always_inline int virtio_dev_tx_single_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool, @@ -1981,7 +1908,7 @@ virtio_dev_tx_single_packed(struct virtio_net *dev, return 0; } -static __rte_unused int +static __rte_always_inline int virtio_dev_tx_batch_packed_zmbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool, @@ -2030,7 +1957,7 @@ free_pkt: return -1; } -static __rte_unused int +static __rte_always_inline int virtio_dev_tx_single_packed_zmbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool, @@ -2061,7 +1988,7 @@ virtio_dev_tx_single_packed_zmbuf(struct virtio_net *dev, return 0; } -static __rte_unused void +static __rte_always_inline void free_zmbuf(struct vhost_virtqueue *vq) { struct zcopy_mbuf *next = NULL; @@ -2102,111 +2029,77 @@ free_zmbuf(struct vhost_virtqueue *vq) } static __rte_noinline uint16_t -virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, - struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) +virtio_dev_tx_packed_zmbuf(struct virtio_net *dev, + struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, + struct rte_mbuf **pkts, + uint32_t count) { - uint16_t i; - - if (unlikely(dev->dequeue_zero_copy)) { - struct zcopy_mbuf *zmbuf, *next; - - for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list); - zmbuf != NULL; zmbuf = next) { - next = TAILQ_NEXT(zmbuf, next); + uint32_t pkt_idx = 0; + uint32_t remained = count; - if (mbuf_is_consumed(zmbuf->mbuf)) { - update_shadow_used_ring_packed(vq, - zmbuf->desc_idx, - 0, - zmbuf->desc_count); + free_zmbuf(vq); - TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next); - restore_mbuf(zmbuf->mbuf); - rte_pktmbuf_free(zmbuf->mbuf); - put_zmbuf(zmbuf); - vq->nr_zmbuf -= 1; + do { + if (remained >= PACKED_BATCH_SIZE) { + if (!virtio_dev_tx_batch_packed_zmbuf(dev, vq, + mbuf_pool, &pkts[pkt_idx])) { + pkt_idx += PACKED_BATCH_SIZE; + remained -= PACKED_BATCH_SIZE; + continue; } } - if (likely(vq->shadow_used_idx)) { - flush_shadow_used_ring_packed(dev, vq); - vhost_vring_call_packed(dev, vq); - } - } - - VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__); - - count = RTE_MIN(count, MAX_PKT_BURST); - VHOST_LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n", - dev->vid, count); - - for (i = 0; i < count; i++) { - struct buf_vector buf_vec[BUF_VECTOR_MAX]; - uint16_t buf_id; - uint32_t buf_len; - uint16_t desc_count, nr_vec = 0; - int err; - - if (unlikely(fill_vec_buf_packed(dev, vq, - vq->last_avail_idx, &desc_count, - buf_vec, &nr_vec, - &buf_id, &buf_len, - VHOST_ACCESS_RO) < 0)) + if (virtio_dev_tx_single_packed_zmbuf(dev, vq, mbuf_pool, + &pkts[pkt_idx])) break; + pkt_idx++; + remained--; - if (likely(dev->dequeue_zero_copy == 0)) - update_shadow_used_ring_packed(vq, buf_id, 0, - desc_count); + } while (remained); - pkts[i] = virtio_dev_pktmbuf_alloc(dev, mbuf_pool, buf_len); - if (unlikely(pkts[i] == NULL)) - break; - - err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts[i], - mbuf_pool); - if (unlikely(err)) { - rte_pktmbuf_free(pkts[i]); - break; - } + if (pkt_idx) + vhost_vring_call_packed(dev, vq); - if (unlikely(dev->dequeue_zero_copy)) { - struct zcopy_mbuf *zmbuf; + return pkt_idx; +} - zmbuf = get_zmbuf(vq); - if (!zmbuf) { - rte_pktmbuf_free(pkts[i]); - break; - } - zmbuf->mbuf = pkts[i]; - zmbuf->desc_idx = buf_id; - zmbuf->desc_count = desc_count; +static __rte_noinline uint16_t +virtio_dev_tx_packed(struct virtio_net *dev, + struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, + struct rte_mbuf **pkts, + uint32_t count) +{ + uint32_t pkt_idx = 0; + uint32_t remained = count; - /* - * Pin lock the mbuf; we will check later to see - * whether the mbuf is freed (when we are the last - * user) or not. If that's the case, we then could - * update the used ring safely. - */ - rte_mbuf_refcnt_update(pkts[i], 1); + do { + rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]); - vq->nr_zmbuf += 1; - TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next); + if (remained >= PACKED_BATCH_SIZE) { + if (!virtio_dev_tx_batch_packed(dev, vq, mbuf_pool, + &pkts[pkt_idx])) { + vhost_flush_dequeue_packed(dev, vq); + pkt_idx += PACKED_BATCH_SIZE; + remained -= PACKED_BATCH_SIZE; + continue; + } } - vq_inc_last_avail_packed(vq, desc_count); - } + if (virtio_dev_tx_single_packed(dev, vq, mbuf_pool, + &pkts[pkt_idx])) + break; + vhost_flush_dequeue_packed(dev, vq); + pkt_idx++; + remained--; - if (likely(dev->dequeue_zero_copy == 0)) { + } while (remained); + + if (vq->shadow_used_idx) do_data_copy_dequeue(vq); - if (unlikely(i < count)) - vq->shadow_used_idx = i; - if (likely(vq->shadow_used_idx)) { - flush_shadow_used_ring_packed(dev, vq); - vhost_vring_call_packed(dev, vq); - } - } - return i; + return pkt_idx; } uint16_t @@ -2282,9 +2175,14 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, count -= 1; } - if (vq_is_packed(dev)) - count = virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts, count); - else + if (vq_is_packed(dev)) { + if (unlikely(dev->dequeue_zero_copy)) + count = virtio_dev_tx_packed_zmbuf(dev, vq, mbuf_pool, + pkts, count); + else + count = virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts, + count); + } else count = virtio_dev_tx_split(dev, vq, mbuf_pool, pkts, count); out: