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Date: Wed, 29 Nov 2023 23:22:30 +0800
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Subject: Re: [PATCH net-next 2/5] virtio_net: Add page_pool support to improve
 performance
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Liang Chen <liangchen.linux@gmail.com>, jasowang@redhat.com,
 virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, xuanzhuo@linux.alibaba.com, kuba@kernel.org,
 edumazet@google.com, davem@davemloft.net, pabeni@redhat.com,
 alexander.duyck@gmail.com
References: <20230526054621.18371-1-liangchen.linux@gmail.com>
 <20230526054621.18371-2-liangchen.linux@gmail.com>
 <c745f67e-91e6-4a32-93f2-dc715056eb51@linux.dev>
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From: Zhu Yanjun <yanjun.zhu@linux.dev>
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在 2023/11/29 22:59, Michael S. Tsirkin 写道:
> On Wed, Nov 29, 2023 at 10:50:57PM +0800, Zhu Yanjun wrote:
>> 在 2023/5/26 13:46, Liang Chen 写道:
>
> what made you respond to a patch from May, now?

I want to apply page_pool to our virtio_net. This virtio_net works on 
our device.

I want to verify whether page_pool on virtio_net with our device can 
improve the performance or not.

And I found that ethtool is wrong.

I use virtio_net on our device. I found that page member variable in rq 
is not used in recv path.

When virtio_net is modprobe, I checked page member variable in rq with 
kprobe or crash tool.  page member variable in rq is always NULL.

But sg in recv path is used.

So how to use page member variable in rq? If page member variable in rq 
is always NULL, can we remove it?

BTW, I use ping and iperf tool to make tests with virtio_net. In the 
tests, page member variable in rq is always NULL.

It is interesting.

Zhu Yanjun

>