vhost: add unlikely annotations to error path

patch 'break out of polling loop on error' caused
a minor performance regression on my machine: recover
that performance by adding a bunch of unlikely annotations
in the error handling.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 54096eef4840..2406377a6e5e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -137,7 +137,7 @@ static void handle_tx(struct vhost_net *net)
                                          &out, &in,
                                          NULL, NULL);
                 /* On error, stop handling until the next kick. */
-                if (head < 0)
+                if (unlikely(head < 0))
                         break;
                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
                 if (head == vq->num) {
@@ -234,7 +234,7 @@ static void handle_rx(struct vhost_net *net)
                                          &out, &in,
                                          vq_log, &log);
                 /* On error, stop handling until the next kick. */
-                if (head < 0)
+                if (unlikely(head < 0))
                         break;
                 /* OK, now we need to know about added descriptors. */
                 if (head == vq->num) {