[PATCH v2 5/5] VSOCK: batch sending rx buffer to increase bandwidth

jiangyiwen
2018-12-12T09:35:27Z

Batch sending rx buffer can improve total bandwidth.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
---
drivers/vhost/vsock.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 9600133..a4bf0a1 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -151,9 +151,11 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
struct vhost_virtqueue *vq)
{
struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
- bool added = false;
bool restart_tx = false;
size_t vsock_hlen;
+ int batch_count = 0;
+
+#define VHOST_VSOCK_BATCH 16

mutex_lock(&vq->mutex);

@@ -194,8 +196,9 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
list_del_init(&pkt->list);
spin_unlock_bh(&vsock->send_pkt_list_lock);

- headcount = get_rx_bufs(vq, vq->heads, vsock_hlen + pkt->len,
- &in, likely(vsock->mergeable) ? UIO_MAXIOV : 1);
+ headcount = get_rx_bufs(vq, vq->heads + batch_count,
+ vsock_hlen + pkt->len, &in,
+ likely(vsock->mergeable) ? UIO_MAXIOV : 1);
if (headcount <= 0) {
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add(&pkt->list, &vsock->send_pkt_list);
@@ -238,8 +241,12 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
remain_len -= tmp_len;
}

- vhost_add_used_n(vq, vq->heads, headcount);
- added = true;
+ batch_count += headcount;
+ if (batch_count > VHOST_VSOCK_BATCH) {
+ vhost_add_used_and_signal_n(&vsock->dev, vq,
+ vq->heads, batch_count);
+ batch_count = 0;
+ }

if (pkt->reply) {
int val;
@@ -258,8 +265,11 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,

virtio_transport_free_pkt(pkt);
}
- if (added)
- vhost_signal(&vsock->dev, vq);
+
+ if (batch_count) {
+ vhost_add_used_and_signal_n(&vsock->dev, vq,
+ vq->heads, batch_count);
+ }

out:
mutex_unlock(&vq->mutex);
--
1.8.3.1