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

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

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.

Zhu Yanjun

>
>
> Thxs, Håkon
>
>> Thanks a lot.
>>
>> Zhu Yanjun
>>
>>> Best Regards,
>>> Xiao Yang