Re: [PATCH] RDMA/rxe: Check the last packet by RXE_END_MASK

[Yanjun Zhu <yanjun.zhu@linux.dev>]

在 2022/1/12 11:58, yangx.jy@fujitsu.com 写道:
> On 2022/1/12 9:19, Yanjun Zhu wrote:
>> 在 2022/1/11 23:16, Haakon Bugge 写道:
>>>> On 11 Jan 2022, at 15:42, Yanjun Zhu <yanjun.zhu@linux.dev> wrote:
>>>>
>>>>
>>>> 在 2022/1/10 13:17, yangx.jy@fujitsu.com 写道:
>>>>> On 2022/1/7 19:49, Yanjun Zhu wrote:
>>>>>> It seems that it does not mean to check the last packet. It means
>>>>>> that
>>>>>> it receives a MSN response.
>>>>> Hi Yanjun,
>>>>>
>>>>> Checking the last packet is a way to indicate that responder has
>>>>> completed an entire request(including multiple packets) and then
>>>>> increases a msn.
>>>> Hi, Xiao
>>>>
>>>> What does the msn mean?
>>> Message Sequence Number.
>> Thanks, Haakon
>>
>> I am reading the following from the spec.
>>
>> "
>>
>> C9-148: An HCA responder using Reliable Connection service shall
>> initialize
>>
>> its MSN value to zero. The responder shall increment its MSN
>> whenever it has successfully completed processing a new, valid request
>> message. The MSN shall not be incremented for duplicate requests. The
>> incremented MSN shall be returned in the last or only packet of an RDMA
>> READ or Atomic response. For RDMA READ requests, the responder
>> may increment its MSN after it has completed validating the request and
>> before it has begun transmitting any of the requested data, and may
>> return
>> the incremented MSN in the AETH of the first response packet. The MSN
>> shall be incremented only once for any given request message.
>>
>> "
>>
>> It seems that the above describe how to handle MSN increment in details.
> Hi Yanjun,
>
> Sorry for the late reply.
>
> Right, 9.7.7.1 GENERATING MSN VALUE section explains Message Sequence

Does your commit take into account of duplicate requests?

Zhu Yanjun

> Number(MSN).
>
> Best Regards,
> Xiao Yang
>> Zhu Yanjun
>>
>>>
>>> Thxs, Håkon
>>>
>>>> Thanks a lot.
>>>>
>>>> Zhu Yanjun
>>>>
>>>>> Best Regards,
>>>>> Xiao Yang