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path: root/drivers/vhost/net.c
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Diffstat (limited to 'drivers/vhost/net.c')
-rw-r--r--drivers/vhost/net.c95
1 files changed, 60 insertions, 35 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 29756d88799b..b2240361f1a1 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -396,13 +396,10 @@ static inline unsigned long busy_clock(void)
return local_clock() >> 10;
}
-static bool vhost_can_busy_poll(struct vhost_dev *dev,
- unsigned long endtime)
+static bool vhost_can_busy_poll(unsigned long endtime)
{
- return likely(!need_resched()) &&
- likely(!time_after(busy_clock(), endtime)) &&
- likely(!signal_pending(current)) &&
- !vhost_has_work(dev);
+ return likely(!need_resched() && !time_after(busy_clock(), endtime) &&
+ !signal_pending(current));
}
static void vhost_net_disable_vq(struct vhost_net *n,
@@ -434,7 +431,8 @@ static int vhost_net_enable_vq(struct vhost_net *n,
static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
struct vhost_virtqueue *vq,
struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num)
+ unsigned int *out_num, unsigned int *in_num,
+ bool *busyloop_intr)
{
unsigned long uninitialized_var(endtime);
int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
@@ -443,9 +441,15 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
if (r == vq->num && vq->busyloop_timeout) {
preempt_disable();
endtime = busy_clock() + vq->busyloop_timeout;
- while (vhost_can_busy_poll(vq->dev, endtime) &&
- vhost_vq_avail_empty(vq->dev, vq))
+ while (vhost_can_busy_poll(endtime)) {
+ if (vhost_has_work(vq->dev)) {
+ *busyloop_intr = true;
+ break;
+ }
+ if (!vhost_vq_avail_empty(vq->dev, vq))
+ break;
cpu_relax();
+ }
preempt_enable();
r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
out_num, in_num, NULL, NULL);
@@ -501,20 +505,24 @@ static void handle_tx(struct vhost_net *net)
zcopy = nvq->ubufs;
for (;;) {
+ bool busyloop_intr;
+
/* Release DMAs done buffers first */
if (zcopy)
vhost_zerocopy_signal_used(net, vq);
-
+ busyloop_intr = false;
head = vhost_net_tx_get_vq_desc(net, vq, vq->iov,
ARRAY_SIZE(vq->iov),
- &out, &in);
+ &out, &in, &busyloop_intr);
/* On error, stop handling until the next kick. */
if (unlikely(head < 0))
break;
/* Nothing new? Wait for eventfd to tell us they refilled. */
if (head == vq->num) {
- if (unlikely(vhost_enable_notify(&net->dev, vq))) {
+ if (unlikely(busyloop_intr)) {
+ vhost_poll_queue(&vq->poll);
+ } else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
vhost_disable_notify(&net->dev, vq);
continue;
}
@@ -645,41 +653,50 @@ static void vhost_rx_signal_used(struct vhost_net_virtqueue *nvq)
nvq->done_idx = 0;
}
-static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk)
+static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk,
+ bool *busyloop_intr)
{
- struct vhost_net_virtqueue *rvq = &net->vqs[VHOST_NET_VQ_RX];
- struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
- struct vhost_virtqueue *vq = &nvq->vq;
+ struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX];
+ struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX];
+ struct vhost_virtqueue *rvq = &rnvq->vq;
+ struct vhost_virtqueue *tvq = &tnvq->vq;
unsigned long uninitialized_var(endtime);
- int len = peek_head_len(rvq, sk);
+ int len = peek_head_len(rnvq, sk);
- if (!len && vq->busyloop_timeout) {
+ if (!len && tvq->busyloop_timeout) {
/* Flush batched heads first */
- vhost_rx_signal_used(rvq);
+ vhost_rx_signal_used(rnvq);
/* Both tx vq and rx socket were polled here */
- mutex_lock_nested(&vq->mutex, 1);
- vhost_disable_notify(&net->dev, vq);
+ mutex_lock_nested(&tvq->mutex, 1);
+ vhost_disable_notify(&net->dev, tvq);
preempt_disable();
- endtime = busy_clock() + vq->busyloop_timeout;
+ endtime = busy_clock() + tvq->busyloop_timeout;
- while (vhost_can_busy_poll(&net->dev, endtime) &&
- !sk_has_rx_data(sk) &&
- vhost_vq_avail_empty(&net->dev, vq))
+ while (vhost_can_busy_poll(endtime)) {
+ if (vhost_has_work(&net->dev)) {
+ *busyloop_intr = true;
+ break;
+ }
+ if ((sk_has_rx_data(sk) &&
+ !vhost_vq_avail_empty(&net->dev, rvq)) ||
+ !vhost_vq_avail_empty(&net->dev, tvq))
+ break;
cpu_relax();
+ }
preempt_enable();
- if (!vhost_vq_avail_empty(&net->dev, vq))
- vhost_poll_queue(&vq->poll);
- else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
- vhost_disable_notify(&net->dev, vq);
- vhost_poll_queue(&vq->poll);
+ if (!vhost_vq_avail_empty(&net->dev, tvq)) {
+ vhost_poll_queue(&tvq->poll);
+ } else if (unlikely(vhost_enable_notify(&net->dev, tvq))) {
+ vhost_disable_notify(&net->dev, tvq);
+ vhost_poll_queue(&tvq->poll);
}
- mutex_unlock(&vq->mutex);
+ mutex_unlock(&tvq->mutex);
- len = peek_head_len(rvq, sk);
+ len = peek_head_len(rnvq, sk);
}
return len;
@@ -786,6 +803,7 @@ static void handle_rx(struct vhost_net *net)
s16 headcount;
size_t vhost_hlen, sock_hlen;
size_t vhost_len, sock_len;
+ bool busyloop_intr = false;
struct socket *sock;
struct iov_iter fixup;
__virtio16 num_buffers;
@@ -809,7 +827,8 @@ static void handle_rx(struct vhost_net *net)
vq->log : NULL;
mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
- while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
+ while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk,
+ &busyloop_intr))) {
sock_len += sock_hlen;
vhost_len = sock_len + vhost_hlen;
headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx,
@@ -820,7 +839,9 @@ static void handle_rx(struct vhost_net *net)
goto out;
/* OK, now we need to know about added descriptors. */
if (!headcount) {
- if (unlikely(vhost_enable_notify(&net->dev, vq))) {
+ if (unlikely(busyloop_intr)) {
+ vhost_poll_queue(&vq->poll);
+ } else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
/* They have slipped one in as we were
* doing that: check again. */
vhost_disable_notify(&net->dev, vq);
@@ -830,6 +851,7 @@ static void handle_rx(struct vhost_net *net)
* they refilled. */
goto out;
}
+ busyloop_intr = false;
if (nvq->rx_ring)
msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
/* On overrun, truncate and discard */
@@ -896,7 +918,10 @@ static void handle_rx(struct vhost_net *net)
goto out;
}
}
- vhost_net_enable_vq(net, vq);
+ if (unlikely(busyloop_intr))
+ vhost_poll_queue(&vq->poll);
+ else
+ vhost_net_enable_vq(net, vq);
out:
vhost_rx_signal_used(nvq);
mutex_unlock(&vq->mutex);
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-26 04:52:33 +0000