| Message ID | 1596339683-117617-1-git-send-email-wenan.mao@linux.alibaba.com |
|---|---|
| State | New |
| Headers | show |
| Series | [-next] virtio_net: Avoid loop in virtnet_poll | expand |
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ba38765..a058da1 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -327,7 +327,8 @@ static void virtqueue_napi_complete(struct napi_struct *napi, opaque = virtqueue_enable_cb_prepare(vq); if (napi_complete_done(napi, processed)) { - if (unlikely(virtqueue_poll(vq, opaque))) + if (unlikely(virtqueue_poll(vq, opaque)) && + unlikely(!virtqueue_is_broken(vq))) virtqueue_napi_schedule(napi, vq); } else { virtqueue_disable_cb(vq);
The loop may exist if vq->broken is true, virtqueue_get_buf_ctx_packed or virtqueue_get_buf_ctx_split will return NULL, so virtnet_poll will reschedule napi to receive packet, it will lead cpu usage(si) to 100%. call trace as below: virtnet_poll virtnet_receive virtqueue_get_buf_ctx virtqueue_get_buf_ctx_packed virtqueue_get_buf_ctx_split virtqueue_napi_complete virtqueue_napi_schedule //it will reschedule napi Signed-off-by: Mao Wenan <wenan.mao@linux.alibaba.com> --- drivers/net/virtio_net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)