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: <deeb8fe7-1f0e-bc1c-cde5-74e9af160bf7@mojatatu.com>
Date:   Fri, 14 Jul 2023 14:49:01 -0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH net 1/3] selftests: tc: set timeout to 15 minutes
Content-Language: en-US
To:     shaozhengchao <shaozhengchao@huawei.com>,
        Matthieu Baerts <matthieu.baerts@tessares.net>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>, Shuah Khan <shuah@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        Paul Blakey <paulb@mellanox.com>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        mptcp@lists.linux.dev
Cc:     Shuah Khan <skhan@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-kselftest@vger.kernel.org, stable@vger.kernel.org
References: <20230713-tc-selftests-lkft-v1-0-1eb4fd3a96e7@tessares.net>
 <20230713-tc-selftests-lkft-v1-1-1eb4fd3a96e7@tessares.net>
 <bf7f8867-6b14-dd53-a6e4-2addee4a5ad8@huawei.com>
From:   Pedro Tammela <pctammela@mojatatu.com>
In-Reply-To: <bf7f8867-6b14-dd53-a6e4-2addee4a5ad8@huawei.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 13/07/2023 23:25, shaozhengchao wrote:
> 
> 
> On 2023/7/14 5:16, Matthieu Baerts wrote:
>> When looking for something else in LKFT reports [1], I noticed that the
>> TC selftest ended with a timeout error:
>>
>>    not ok 1 selftests: tc-testing: tdc.sh # TIMEOUT 45 seconds
>>
>> The timeout had been introduced 3 years ago, see the Fixes commit below.
>>
>> This timeout is only in place when executing the selftests via the
>> kselftests runner scripts. I guess this is not what most TC devs are
>> using and nobody noticed the issue before.
>>
>> The new timeout is set to 15 minutes as suggested by Pedro [2]. It looks
>> like it is plenty more time than what it takes in "normal" conditions.
>>
>> Fixes: 852c8cbf34d3 ("selftests/kselftest/runner.sh: Add 45 second 
>> timeout per test")
>> Cc: stable@vger.kernel.org
>> Link: 
>> https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230711/testrun/18267241/suite/kselftest-tc-testing/test/tc-testing_tdc_sh/log [1]
>> Link: 
>> https://lore.kernel.org/netdev/0e061d4a-9a23-9f58-3b35-d8919de332d7@tessares.net/T/ [2]
>> Suggested-by: Pedro Tammela <pctammela@mojatatu.com>
>> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
>> ---
>>   tools/testing/selftests/tc-testing/settings | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/tools/testing/selftests/tc-testing/settings 
>> b/tools/testing/selftests/tc-testing/settings
>> new file mode 100644
>> index 000000000000..e2206265f67c
>> --- /dev/null
>> +++ b/tools/testing/selftests/tc-testing/settings
>> @@ -0,0 +1 @@
>> +timeout=900
>>
> I remember last year when I tested all the tdc cases（qdisc + filter +
> action + infra） in my vm machine, it took me nearly 20 minutes.
> So I think it should be more than 1200 seconds if all cases need to be
> tested.
> 
> Maybe we should really optimize the parallel execution process of tdc.

Let's try to spend some cycles improving the tdc code performance first.
TDC boils down essentially to:
- Setup namespace (if needed)
- Setup network interfaces
- Spawn a few processes
- Match a regex
- Bring down namespace

Nothing above screams expensive, so I'm sure there are some low hanging 
fruits to improve the overall wall time even in debug kernels.