Commit 8c2e6b26ffe2 ("vhost/net: Defer TX queue re-enable until after
sendmsg") tries to defer the notification enabling by moving the logic
out of the loop after the vhost_tx_batch() when nothing new is spotted.
This caused unexpected side effects as the new logic is reused for
several other error conditions.
A previous patch reverted 8c2e6b26ffe2. Now, bring the performance
back up by flushing batched buffers before enabling notifications.
Reported-by: Jon Kohler <j...@nutanix.com>
Cc: sta...@vger.kernel.org
Fixes: 8c2e6b26ffe2 ("vhost/net: Defer TX queue re-enable until after sendmsg")
Signed-off-by: Jason Wang <jasow...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
drivers/vhost/net.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 57efd5c55f89..35ded4330431 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -780,6 +780,11 @@ static void handle_tx_copy(struct vhost_net *net, struct
socket *sock)
break;
/* Nothing new? Wait for eventfd to tell us they refilled. */
if (head == vq->num) {
+ /* Flush batched packets to handle pending RX
+ * work (if busyloop_intr is set) and to avoid
+ * unnecessary virtqueue kicks.
+ */
+ vhost_tx_batch(net, nvq, sock, &msg);
if (unlikely(busyloop_intr)) {
vhost_poll_queue(&vq->poll);
} else if (unlikely(vhost_enable_notify(&net->dev,
--
2.34.1
