vhost: improve batched copies performance

Instead of copying batch_copy_nb_elems into the stack,
this patch uses it directly.

Small performance gain of 3% is seen when running PVP
benchmark.

Acked-by: Zhihong Wang <zhihong.wang@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
This commit is contained in:
Maxime Coquelin 2018-05-29 11:45:14 +02:00 committed by Ferruh Yigit
parent 24e4844048
commit c89e52d9c8

View File

@ -352,7 +352,6 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
struct rte_mbuf *hdr_mbuf; struct rte_mbuf *hdr_mbuf;
struct batch_copy_elem *batch_copy = vq->batch_copy_elems; struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL; struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
uint16_t copy_nb = vq->batch_copy_nb_elems;
int error = 0; int error = 0;
if (unlikely(m == NULL)) { if (unlikely(m == NULL)) {
@ -493,7 +492,8 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail); cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail);
if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size)) { if (likely(cpy_len > MAX_BATCH_LEN ||
vq->batch_copy_nb_elems >= vq->size)) {
rte_memcpy((void *)((uintptr_t)(desc_addr + rte_memcpy((void *)((uintptr_t)(desc_addr +
desc_offset)), desc_offset)),
rte_pktmbuf_mtod_offset(m, void *, mbuf_offset), rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
@ -503,13 +503,14 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
cpy_len, 0); cpy_len, 0);
} else { } else {
batch_copy[copy_nb].dst = batch_copy[vq->batch_copy_nb_elems].dst =
(void *)((uintptr_t)(desc_addr + desc_offset)); (void *)((uintptr_t)(desc_addr + desc_offset));
batch_copy[copy_nb].src = batch_copy[vq->batch_copy_nb_elems].src =
rte_pktmbuf_mtod_offset(m, void *, mbuf_offset); rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
batch_copy[copy_nb].log_addr = desc_gaddr + desc_offset; batch_copy[vq->batch_copy_nb_elems].log_addr =
batch_copy[copy_nb].len = cpy_len; desc_gaddr + desc_offset;
copy_nb++; batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
vq->batch_copy_nb_elems++;
} }
mbuf_avail -= cpy_len; mbuf_avail -= cpy_len;
@ -520,7 +521,6 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
} }
out: out:
vq->batch_copy_nb_elems = copy_nb;
return error; return error;
} }
@ -766,7 +766,6 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
/* A counter to avoid desc dead loop chain */ /* A counter to avoid desc dead loop chain */
uint32_t nr_desc = 1; uint32_t nr_desc = 1;
struct batch_copy_elem *batch_copy = vq->batch_copy_elems; struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
uint16_t copy_nb = vq->batch_copy_nb_elems;
int error = 0; int error = 0;
desc = &descs[desc_idx]; desc = &descs[desc_idx];
@ -905,7 +904,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
mbuf_avail = cpy_len; mbuf_avail = cpy_len;
} else { } else {
if (likely(cpy_len > MAX_BATCH_LEN || if (likely(cpy_len > MAX_BATCH_LEN ||
copy_nb >= vq->size || vq->batch_copy_nb_elems >= vq->size ||
(hdr && cur == m) || (hdr && cur == m) ||
desc->len != desc_chunck_len)) { desc->len != desc_chunck_len)) {
rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
@ -914,14 +913,15 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
desc_offset)), desc_offset)),
cpy_len); cpy_len);
} else { } else {
batch_copy[copy_nb].dst = batch_copy[vq->batch_copy_nb_elems].dst =
rte_pktmbuf_mtod_offset(cur, void *, rte_pktmbuf_mtod_offset(cur, void *,
mbuf_offset); mbuf_offset);
batch_copy[copy_nb].src = batch_copy[vq->batch_copy_nb_elems].src =
(void *)((uintptr_t)(desc_addr + (void *)((uintptr_t)(desc_addr +
desc_offset)); desc_offset));
batch_copy[copy_nb].len = cpy_len; batch_copy[vq->batch_copy_nb_elems].len =
copy_nb++; cpy_len;
vq->batch_copy_nb_elems++;
} }
} }
@ -1015,7 +1015,6 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
vhost_dequeue_offload(hdr, m); vhost_dequeue_offload(hdr, m);
out: out:
vq->batch_copy_nb_elems = copy_nb;
return error; return error;
} }