On 5/19/22 07:22, Edward Srouji wrote:
>
> On 5/19/2022 6:04 AM, lizhijian@xxxxxxxxxxx wrote:
>>
>> On 18/05/2022 11:41, Bob Pearson wrote:
>>>
>>> -------- Forwarded Message --------
>>> Subject: Re: Bug in pyverbs for test_qp_ex_rc_bind_mw
>>> Date: Tue, 17 May 2022 22:41:08 -0500
>>> From: Bob Pearson <rpearsonhpe@xxxxxxxxx>
>>> To: Jason Gunthorpe <jgg@xxxxxxxxxx>, Zhu Yanjun <zyjzyj2000@xxxxxxxxx>, Edward Srouji <edwards@xxxxxxxxxx>, Leon Romanovsky <leon@xxxxxxxxxx>
>>>
>>> On 5/17/22 21:57, Bob Pearson wrote:
>>>> test_qp_ex_rc_bind_mw has an error in that the new_rkey is computed from the old mr rkey and not the old mw rkey.
>>>> The following lines
>>>>
>>>> mw = MW(server.pd, mw_type=e.IBV_MW_TYPE_2)
>>>> ...
>>>> new_rkey = inc_rkey(server.mr.rkey)
>>>> server.qp.wr_bind_mw(mw, new_rkey, bind_info)
>>>>
>>>> will compute a new rkey with the same index as mr and a key portion that is one larger than mr modulo 256.
>>>> This is passed to wr_bind_mw which expects a parameter with a new key portion of the mw (not the mr).
>>>> The memory windows implementation in rxe generates a random initial rkey for mw and for bind_mw it
>>>> checks that the new 8 bit key is different than the old key. Since the mr and mw are random wrt each other
>>>> we expect that the new key will match the old key approx 1 out of 256 test runs which will cause an error
>>>> which is just what I see.
>>>>
>>>> The correct code should be
>>>>
>>>> new_key = inc_rkey(<old mw.rkey>)
>>>>
>>>> which will guarantee that it is always different than the previous key. The problem is I can't figure out
>>>> how to compute the rkey from the mw or I would submit a patch.
>>>>
>>>> Bob
>>>>
>>> If in test_qpex.py I type
>>>
>>> print("mw = ", mw)
>>> print("mr = ", self.server.mr)
>>>
>>> I get
>>>
>>> mw = MW:
>>> Rkey : 12345678
>>> Handle : 4
>>> MW Type : IBV_MW_TYPE_2
>>>
>>> mr = MR
>>> lkey : 432134
>>> rkey : 432134
>>> length : 1024
>>> buf : 9403912345678
>>> handle : 2
>>>
>>> The difference is the colon ':' after MW and caps.
>> For the difference, just post a RP to make them identical: https://github.com/linux-rdma/rdma-core/pull/1175
> Thanks for the adjustment.
>> Thanks
>> Zhijian
>>
>>> I can refer to mr.rkey as self.server.mr.rkey no problem
>>>
>>> but mw.Rkey doesn't work. Neither does mw.rkey or anything else I have thought of.
>
> mw.rkey should work... I noticed that you've already figured that out and sent a patch.
I can't believe I didn't try that. It was 1 AM and I was tired. A nights sleep resolved the
issue and reading the pyx code.
Bob
>
> We expose the MW rkey in pyverbs (within the cython code).
> If you still have an issue with it please let me know.
>
>>>
>>> I hate python. Just hate it.
> Don't hate the game, hate the player :) (in this case).
>>> Bob
