The comment we have is just repeating what the code does. Include the *reason* for the condition instead.
Cc: Stefano Garzarella <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> --- net/vmw_vsock/virtio_transport_common.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 94cc0fa3e848..5bb70c692b1e 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -307,8 +307,13 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, spin_unlock_bh(&vvs->rx_lock); - /* We send a credit update only when the space available seen - * by the transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + /* To reduce the number of credit update messages, + * don't update credits as long as lots of space is available. + * Note: the limit chosen here is arbitrary. Setting the limit + * too high causes extra messages. Too low causes transmitter + * stalls. As stalls are in theory more expensive than extra + * messages, we set the limit to a high value. TODO: experiment + * with different values. */ if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) { virtio_transport_send_credit_update(vsk, -- MST
