Re: [RFC PATCH net-next 02/12] vhost_net: introduce vhost_exceeds_weight()

[Jason Wang]

On 2018年05月22日 00:29, Jesse Brandeburg wrote:

On Mon, 21 May 2018 17:04:23 +0800 Jason wrote:

Signed-off-by: Jason Wang <jasow...@redhat.com>
---
  drivers/vhost/net.c | 13 ++++++++-----
  1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 15d191a..de544ee 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -479,6 +479,12 @@ static size_t init_iov_iter(struct vhost_virtqueue *vq, 
struct iov_iter *iter,
        return len;
  }

+static bool vhost_exceeds_weight(int pkts, int total_len)

+{
+       return unlikely(total_len >= VHOST_NET_WEIGHT) ||
+              unlikely(pkts >= VHOST_NET_PKT_WEIGHT);

I was going to say just one unlikely, but then the caller of this
function also says unlikely(vhost_exceeds...), so I think you should
just drop the unlikely statements here (both of them)

Ok.

+}
+
  /* Expects to be always run from workqueue - which acts as
   * read-size critical section for our kind of RCU. */
  static void handle_tx(struct vhost_net *net)
@@ -570,7 +576,6 @@ static void handle_tx(struct vhost_net *net)
                        msg.msg_control = NULL;
                        ubufs = NULL;
                }
-

unrelated whitespace changes?

Yes.

Thanks

                total_len += len;
                if (total_len < VHOST_NET_WEIGHT &&
                    !vhost_vq_avail_empty(&net->dev, vq) &&
@@ -600,8 +605,7 @@ static void handle_tx(struct vhost_net *net)
                else
                        vhost_zerocopy_signal_used(net, vq);
                vhost_net_tx_packet(net);
-               if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
-                   unlikely(++sent_pkts >= VHOST_NET_PKT_WEIGHT)) {
+               if (unlikely(vhost_exceeds_weight(++sent_pkts, total_len))) {
                        vhost_poll_queue(&vq->poll);
                        break;
                }
@@ -887,8 +891,7 @@ static void handle_rx(struct vhost_net *net)
                if (unlikely(vq_log))
                        vhost_log_write(vq, vq_log, log, vhost_len);
                total_len += vhost_len;
-               if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
-                   unlikely(++recv_pkts >= VHOST_NET_PKT_WEIGHT)) {
+               if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) {
                        vhost_poll_queue(&vq->poll);
                        goto out;
                }