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>
---
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 53703fe03681..23396b996214 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 buf_alloc;
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 694d9805f989..f7b0c4911308 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -212,6 +212,7 @@ 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->rx_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->rx_lock);
@@ -262,6 +263,7 @@ 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);
@@ -292,11 +294,19 @@ 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
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