Commit e4304516 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

vhost-net: flush batched before enabling notifications 



Commit 8c2e6b26 ("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 8c2e6b26. Now, bring the performance
back up by flushing batched buffers before enabling notifications.

Reported-by: default avatarJon Kohler <jon@nutanix.com>
Cc: stable@vger.kernel.org
Fixes: 8c2e6b26 ("vhost/net: Defer TX queue re-enable until after sendmsg")
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Message-Id: <20250917063045.2042-3-jasowang@redhat.com>
parent 41741527

drivers/vhost/net.c

+5 −0
Original line number Diff line number Diff line
@@ -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,