In order to reduce the number of credit update messages,
we send them only when the space available seen by the
transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE.
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
include/linux/virtio_vsock.h | 1 +
net/vmw_vsock/virtio_transport_common.c | 16 +++++++++++++---
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 7d973903f52e..49fc9d20bc43 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -41,6 +41,7 @@ struct virtio_vsock_sock {
/* Protected by rx_lock */
u32 fwd_cnt;
+ u32 last_fwd_cnt;
u32 rx_bytes;
struct list_head rx_queue;
};
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 095221f94786..a85559d4d974 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -211,6 +211,7 @@ static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
{
spin_lock_bh(&vvs->tx_lock);
+ vvs->last_fwd_cnt = vvs->fwd_cnt;
pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
spin_unlock_bh(&vvs->tx_lock);
@@ -261,6 +262,7 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
struct virtio_vsock_sock *vvs = vsk->trans;
struct virtio_vsock_pkt *pkt;
size_t bytes, total = 0;
+ u32 free_space;
int err = -EFAULT;
spin_lock_bh(&vvs->rx_lock);
@@ -291,11 +293,19 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
virtio_transport_free_pkt(pkt);
}
}
+
+ free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
+
spin_unlock_bh(&vvs->rx_lock);
- /* Send a credit pkt to peer */
- virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
- NULL);
+ /* We send a credit update only when the space available seen
+ * by the transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE
+ */
+ if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
+ virtio_transport_send_credit_update(vsk,
+ VIRTIO_VSOCK_TYPE_STREAM,
+ NULL);
+ }
return total;
--
2.20.1
