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Message-ID: <c4397388-dc39-4799-b386-93ce5956c106@linux.dev>
Date:   Thu, 30 Nov 2023 13:30:40 +0800
MIME-Version: 1.0
Subject: Re: [PATCH net-next 2/5] virtio_net: Add page_pool support to improve
 performance
To:     Xuan Zhuo <xuanzhuo@linux.alibaba.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, kuba@kernel.org, edumazet@google.com,
        davem@davemloft.net, pabeni@redhat.com, alexander.duyck@gmail.com,
        "Michael S. Tsirkin" <mst@redhat.com>
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 <1701311694.1163726-1-xuanzhuo@linux.alibaba.com>
From:   Zhu Yanjun <yanjun.zhu@linux.dev>
In-Reply-To: <1701311694.1163726-1-xuanzhuo@linux.alibaba.com>
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在 2023/11/30 10:34, Xuan Zhuo 写道:
> On Wed, 29 Nov 2023 23:29:10 +0800, Zhu Yanjun <yanjun.zhu@linux.dev> wrote:
>> 在 2023/11/29 23:22, Zhu Yanjun 写道:
>>> 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.
>>
>> And I replaced page member variable in rq with page_pool, but the
>> statistics of page_pool are always 0.
>>
>> It is interesting that page_pool member variable in rq is not used in
>> ping and iperf tests.
>>
>> I am not sure what tests can make page member variable not NULL. ^_^
> Do you mean rq->pages?
>
> That is for big mode.

Hi, Xuan

Got it. What is big mode? Do you mean big packet size? I run iperf with 
the packet size 2^23.

The rq->pages is still NULL.

It is interesting.

Zhu Yanjun


>
> Thanks.
>
>
>> Best Regards,
>>
>> Zhu Yanjun
>>
>>
>>> It is interesting.
>>>
>>> Zhu Yanjun
>>>