Re: [PATCH net-next v4 4/4] virtio-net: support rx netdim

在 2023/11/22 下午5:29, Yinjun Zhang 写道:

On Mon, 20 Nov 2023 20:37:34 +0800, Heng Qi wrote:
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quoted

@@ -2179,6 +2220,7 @@ static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
  	virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
  	napi_disable(&vi->rq[qp_index].napi);
  	xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq);
+	cancel_work_sync(&vi->rq[qp_index].dim.work);

I'm not sure, but please check if here may cause deadlock:
  rtnl_lock held ->
  .ndo_stop ->
  virtnet_disable_queue_pair() ->
  cancel_work_sync() ->
  virtnet_rx_dim_work() ->
  rtnl_lock()

Good catch!

I tried using cancel_work() which solves the problem. Additionally I 
tested the
scenario of ctrl cmd/.remove/.ndo_stop()/dim_work when there is a lot of 
concurrency,
and this can work very well.

Thanks!

quoted

  }
  
  static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)

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