diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 93f2d6741f34..28ad7752e0f3 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -197,8 +197,18 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) { struct vhost_ubuf_ref *ubufs = ubuf->ctx; struct vhost_virtqueue *vq = ubufs->vq; + int cnt = atomic_read(&ubufs->kref.refcount); - vhost_poll_queue(&vq->poll); + /* + * Trigger polling thread if guest stopped submitting new buffers: + * in this case, the refcount after decrement will eventually reach 1 + * so here it is 2. + * We also trigger polling periodically after each 16 packets + * (the value 16 here is more or less arbitrary, it's tuned to trigger + * less than 10% of times). + */ + if (cnt <= 2 || !(cnt % 16)) + vhost_poll_queue(&vq->poll); /* set len to mark this desc buffers done DMA */ vq->heads[ubuf->desc].len = success ? VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN;