Commit 0d197a14 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio-net: add cond_resched() to the command waiting loop 



Adding cond_resched() to the command waiting loop for a better
co-operation with the scheduler. This allows to give CPU a breath to
run other task(workqueue) instead of busy looping when preemption is
not allowed on a device whose CVQ might be slow.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20230720083839.481487-3-jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarShannon Nelson <shannon.nelson@amd.com>
parent b9f74252

drivers/net/virtio_net.c

+3 −1
Original line number Diff line number Diff line
@@ -2570,8 +2570,10 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, 
	 * into the hypervisor, so the request should be handled immediately.

	 */

	while (!virtqueue_get_buf(vi->cvq, &tmp) &&

	       !virtqueue_is_broken(vi->cvq))

	       !virtqueue_is_broken(vi->cvq)) {

		cond_resched();

		cpu_relax();

	}



	return vi->ctrl->status == VIRTIO_NET_OK;

}