Re: [dpdk-dev] [PATCH] app/testpmd: fix the default RSS key configuration

[oulijun <oulijun@huawei.com>]

在 2020/8/4 17:36, Phil Yang 写道:
>> -----Original Message-----
>> From: oulijun <oulijun@huawei.com>
>> Sent: Tuesday, August 4, 2020 9:29 AM
>> To: Phil Yang <Phil.Yang@arm.com>; wenzhuo.lu@intel.com;
>> beilei.xing@intel.com; bernard.iremonger@intel.com;
>> adrien.mazarguil@6wind.com; ferruh.yigit@intel.com
>> Cc: dev@dpdk.org; linuxarm@huawei.com; nd <nd@arm.com>
>> Subject: Re: [dpdk-dev] [PATCH] app/testpmd: fix the default RSS key
>> configuration
>>
>>
>>
>> 在 2020/7/17 15:29, Phil Yang 写道:
>>> <snip>
>>>
>>>>>> Subject: [dpdk-dev] [PATCH] app/testpmd: fix the default RSS key
>>>>>> configuration
>>>>>>
>>>>>> When an user runs a flow create cmd to configure an RSS rule
>>>>>> without specifying the empty rss actions in testpmd, this mean
>>>>>> that the flow gets the default RSS functions. However, the
>>>>>> testpmd is not set the default RSS key incorrectly when RSS key
>>>>>> is specified in flow create cmd.
>>>>> Hi Lijun,
>>>>>
>>>>> I think it works.
>>>>> When we create an RSS flow rule which doesn't specify any 'rss-hash-
>> key',
>>>> the 'rss-hash-key' will be updated with the default key.
>>>>> Step 1:
>>>>> testpmd> show port 0 rss-hash key
>>>>> RSS functions:
>>>>>     all ipv4-frag ipv4-other ipv6-frag ipv6-other ip
>>>>> RSS key:
>>>>>
>>>>
>> 4439796BB54C5023B675EA5B124F9F30B8A2C03DDFDC4D02A08C9B334AF64A4
>>>> C05C6FA343958D8557D99583AE138C92E81150366
>>>>> Step 2:
>>>>> testpmd> flow create 0 ingress pattern eth / ipv4 / udp / end actions rss
>>>> types ipv4-udp end queues end / end
>>>>> Flow rule #0 created
>>>>>
>>>>> Step 3:
>>>>> testpmd> show port 0 rss-hash key
>>>>> RSS functions:
>>>>>     all ipv4-udp udp
>>>>> RSS key:
>>>>>
>>>>
>> 74657374706D6427732064656661756C74205253532068617368206B65792C206F
>>>> 7665727269646520697420666F722062657474
>>>>>
>>>>> Thanks,
>>>>> Phil
>>>> Yes, However, it is not the default value that users use when testpmd
>>>> starts. This may mislead users. When the driver is initialized, the
>>>> default key used by the driver is provided for users. The key varies
>>>> according to the DPDK vendor.However, after the DPDK is initialized, if
>>>> the user runs the flow create command without specifying the rss key,
>>>> the driver obtains another default key value, which may be different
>>>> from the default value expected by the user.
>>> It needs a dummy key.
>>> a4391f8bae85 - app/testpmd: set default RSS key as null
>> Hi, Phil Yang
>>      Yes, I've reviewed the patch("a4391f8bae85 - app/testpmd: set
>> default RSS key as null") and read all other people's comments.
>> However, the patch has been reverted in V2 and restored to the orginal
>> states.  The link as follows:
>> https://patches.dpdk.org/patch/47961/
> 
> I got your point now.
> Your patch makes testpmd using the valid NIC default RSS hash key as the flow rule default RSS, is that right?
> 
Yes. Recently, I've been further testing the patch. I found the other 
question. When I create a flow with RSS by used the following cmd.
testpmd>flow create 0 ingress pattern end actions rss types ipv4-tcp end 
/ end

next, I run flow flush 0 and re-create a flow with RSS
testpmd> flow flush 0
testpmd> flow create 0 ingress pattern end actions rss types ipv4-tcp end

As a result, the key is 0 by show port rss-hash key because it needs to 
memset 0 for rss_info when flush

Thanks

Lijun Ou
> The patch looks good to me. Please fix the typo in your commit message and make it more accurate.
> For example, you can put the cmd line and the expected output in the commit message.
> 
>> I also don't think the key_len parameter is very profitable
>> for users to configure.  Others say that other optimizations will be
>> considered later. Do you have any plans?
> 
> I have no plans for it now.
> 
> Thanks,
> Phil
>