Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <ef0371ebc094e2c0778badca69ea0043b98589aa.camel@redhat.com>
Subject: Re: [PATCH linux-next 1/3] selftests: net: udpgso_bench_rx: Fix
 verifty exceptions
From:   Paolo Abeni <pabeni@redhat.com>
To:     Yang Yang <yang.yang29@zte.com.cn>, davem@davemloft.net,
        edumazet@google.com, willemdebruijn.kernel@gmail.com
Cc:     kuba@kernel.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, netdev@vger.kernel.org,
        shuah@kernel.org, zhang.yunkai@zte.com.cn, xu.xin16@zte.com.cn,
        Xuexin Jiang <jiang.xuexin@zte.com.cn>
Date:   Tue, 18 Apr 2023 16:20:12 +0200
In-Reply-To: <20230417122423.193237-1-yang.yang29@zte.com.cn>
References: <202304172017351308785@zte.com.cn>
         <20230417122423.193237-1-yang.yang29@zte.com.cn>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.46.4 (3.46.4-1.fc37) 
MIME-Version: 1.0
Precedence: bulk

On Mon, 2023-04-17 at 20:24 +0800, Yang Yang wrote:
> From: Zhang Yunkai (CGEL ZTE) <zhang.yunkai@zte.com.cn>
>=20
> The verification function of this test case is likely to encounter the
> following error, which may confuse users.
>=20
> Executing the following command fails:
> bash# udpgso_bench_tx -l 4 -4 -D "$DST"
> bash# udpgso_bench_tx -l 4 -4 -D "$DST" -S 0
> bash# udpgso_bench_rx -4 -G -S 1472 -v
> udpgso_bench_rx: data[1472]: len 2944, a(97) !=3D q(113)


As noted by Willem, both the commit message and the above command
sequence is quite confusing. Please reorder the commands in the exact
sequence you run them, presumably:

udpgso_bench_rx -4 -G -S 1472 -v &
udpgso_bench_tx -l 4 -4 -D "$DST" -S 0


> This is because the sending buffers are not aligned by 26 bytes, and the
> GRO is not merged sequentially, and the receiver does not judge this
> situation. We do the validation after the data is split at the receiving
> end, just as the application actually uses this feature.

The wording from Willem response is much more clear. If applicable,
please use such text.

BTW I could not reproduce the issue with any permutation of the
suggested commands I could think of, so possibly that section need some
extra clarification.

Thanks,

Paolo