d/numam-dpdk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

vhost: simplify async enqueue completion

Browse Source 
vhost_poll_enqueue_completed() assumes some inflight
packets could have been completed in a previous call but
not returned to the application. But this is not the case,
since check_completed_copies callback is never called with
more than the current count as argument.

In other words, async->last_pkts_n is always 0. Removing it
greatly simplifies the function.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>
This commit is contained in:
Maxime Coquelin 2021-10-26 18:28:59 +02:00
parent 2cbe826e26
commit a3cfa8081f
2 changed files with 28 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
lib/vhost/vhost.h
View File

@ -141,7 +141,6 @@ struct vhost_async {
struct async_inflight_info *pkts_info;
uint16_t pkts_idx;
uint16_t pkts_inflight_n;
uint16_t last_pkts_n;
union {
struct vring_used_elem *descs_split;
struct vring_used_elem_packed *buffers_packed;

76
lib/vhost/virtio_net.c
View File

@ -1619,7 +1619,11 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
vq->shadow_used_idx);
async->desc_idx_split += vq->shadow_used_idx;
async->pkts_idx += pkt_idx;
if (async->pkts_idx >= vq->size)
async->pkts_idx -= vq->size;
async->pkts_inflight_n += pkt_idx;
vq->shadow_used_idx = 0;
}
@ -1921,68 +1925,44 @@ static __rte_always_inline uint16_t
vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint16_t count)
{
struct vhost_virtqueue *vq;
struct vhost_async *async;
struct async_inflight_info *pkts_info;
struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
struct vhost_async *async = vq->async;
struct async_inflight_info *pkts_info = async->pkts_info;
int32_t n_cpl;
uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0, n_buffers = 0;
uint16_t start_idx, pkts_idx, vq_size;
uint16_t from, i;
uint16_t n_descs = 0, n_buffers = 0;
uint16_t start_idx, from, i;
vq = dev->virtqueue[queue_id];
async = vq->async;
pkts_idx = async->pkts_idx % vq->size;
pkts_info = async->pkts_info;
vq_size = vq->size;
start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
vq_size, async->pkts_inflight_n);
start_idx = virtio_dev_rx_async_get_info_idx(async->pkts_idx,
vq->size, async->pkts_inflight_n);
if (count > async->last_pkts_n) {
n_cpl = async->ops.check_completed_copies(dev->vid,
queue_id, 0, count - async->last_pkts_n);
if (likely(n_cpl >= 0)) {
n_pkts_cpl = n_cpl;
} else {
VHOST_LOG_DATA(ERR,
"(%d) %s: failed to check completed copies for queue id %d.\n",
n_cpl = async->ops.check_completed_copies(dev->vid, queue_id, 0, count);
if (unlikely(n_cpl < 0)) {
VHOST_LOG_DATA(ERR, "(%d) %s: failed to check completed copies for queue id %d.\n",
dev->vid, __func__, queue_id);
n_pkts_cpl = 0;
}
}
n_pkts_cpl += async->last_pkts_n;
n_pkts_put = RTE_MIN(n_pkts_cpl, count);
if (unlikely(n_pkts_put == 0)) {
async->last_pkts_n = n_pkts_cpl;
return 0;
}
if (vq_is_packed(dev)) {
for (i = 0; i < n_pkts_put; i++) {
from = (start_idx + i) % vq_size;
n_buffers += pkts_info[from].nr_buffers;
pkts[i] = pkts_info[from].mbuf;
}
} else {
for (i = 0; i < n_pkts_put; i++) {
from = (start_idx + i) & (vq_size - 1);
n_descs += pkts_info[from].descs;
pkts[i] = pkts_info[from].mbuf;
}
if (n_cpl == 0)
return 0;
for (i = 0; i < n_cpl; i++) {
from = (start_idx + i) % vq->size;
/* Only used with packed ring */
n_buffers += pkts_info[from].nr_buffers;
/* Only used with split ring */
n_descs += pkts_info[from].descs;
pkts[i] = pkts_info[from].mbuf;
}
async->last_pkts_n = n_pkts_cpl - n_pkts_put;
async->pkts_inflight_n -= n_pkts_put;
async->pkts_inflight_n -= n_cpl;
if (likely(vq->enabled && vq->access_ok)) {
if (vq_is_packed(dev)) {
write_back_completed_descs_packed(vq, n_buffers);
vhost_vring_call_packed(dev, vq);
} else {
write_back_completed_descs_split(vq, n_descs);
__atomic_add_fetch(&vq->used->idx, n_descs,
__ATOMIC_RELEASE);
__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
vhost_vring_call_split(dev, vq);
}
} else {
@ -1995,7 +1975,7 @@ vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id,
}
}
return n_pkts_put;
return n_cpl;
}
uint16_t