Re: [PATCH net-next v2 2/5] virtio-net: transmit napi

From: Jason Wang <jasowang@redhat.com>
To: Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
	netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>,
	virtualization@lists.linux-foundation.org, davem@davemloft.net,
	mst@redhat.com
Subject: Re: [PATCH net-next v2 2/5] virtio-net: transmit napi
Date: Thu, 20 Apr 2017 14:27:03 +0800	[thread overview]
Message-ID: <2ae5889b-69d4-3041-d7fd-a7ea38e8c4e2@redhat.com> (raw)
In-Reply-To: <20170418202108.61920-3-willemdebruijn.kernel@gmail.com>

On 2017年04月19日 04:21, Willem de Bruijn wrote:
> +static void virtnet_napi_tx_enable(struct virtnet_info *vi,
> +				   struct virtqueue *vq,
> +				   struct napi_struct *napi)
> +{
> +	if (!napi->weight)
> +		return;
> +
> +	if (!vi->affinity_hint_set) {
> +		napi->weight = 0;
> +		return;
> +	}
> +
> +	return virtnet_napi_enable(vq, napi);
> +}
> +
>   static void refill_work(struct work_struct *work)

Maybe I was wrong, but according to Michael's comment it looks like he 
want check affinity_hint_set just for speculative tx polling on rx napi 
instead of disabling it at all.

And I'm not convinced this is really needed, driver only provide 
affinity hint instead of affinity, so it's not guaranteed that tx and rx 
interrupt are in the same vcpus.

Thanks
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