svn commit: r261168 - head/sys/dev/virtio/network

[Bryan Venteicher]

Author: bryanv
Date: Sat Jan 25 19:58:53 2014
New Revision: 261168
URL: http://svnweb.freebsd.org/changeset/base/261168

Log:
  Check for a full virtqueue in the multiqueue transmit path
  
  With most hosts, we'll negotiate indirect descriptors, so all we
  need is one available descriptor to transmit a frame.

Modified:
  head/sys/dev/virtio/network/if_vtnet.c

Modified: head/sys/dev/virtio/network/if_vtnet.c
==============================================================================
--- head/sys/dev/virtio/network/if_vtnet.c	Sat Jan 25 19:57:30 2014	(r261167)
+++ head/sys/dev/virtio/network/if_vtnet.c	Sat Jan 25 19:58:53 2014	(r261168)
@@ -2243,6 +2243,12 @@ vtnet_txq_mq_start_locked(struct vtnet_t
 	vtnet_txq_eof(txq);
 
 	while ((m = drbr_peek(ifp, br)) != NULL) {
+		if (virtqueue_full(vq)) {
+			drbr_putback(ifp, br, m);
+			error = ENOBUFS;
+			break;
+		}
+
 		error = vtnet_txq_encap(txq, &m);
 		if (error) {
 			if (m != NULL)