Re: [PATCH RFC V2 0/6] rxe_map_mr_sg() fix cleanup and refactor

[Zhijian Li (Fujitsu)]

On 03/11/2023 21:00, Zhu Yanjun wrote:
> 在 2023/11/3 17:55, Li Zhijian 写道:
>> I don't collect the Reviewed-by to the patch1-2 this time, since i
>> think we can make it better.
>>
>> Patch1-2: Fix kernel panic[1] and benifit to make srp work again.
>>            Almost nothing change from V1.
>> Patch3-5: cleanups # newly add
>> Patch6: make RXE support PAGE_SIZE aligned mr # newly add, but not fully tested
>>
>> My bad arm64 mechine offten hangs when doing blktests even though i use the
>> default siw driver.
>>
>> - nvme and ULPs(rtrs, iser) always registers 4K mr still don't supported yet.
> 
> Zhijian
> 
> Please read carefully the whole discussion about this problem. You will find a lot of valuable suggestions, especially suggestions from Jason.

Okay, i will read it again. If you can tell me which thread, that would be better.


> 
>  From the whole discussion, it seems that the root cause is very clear.
> We need to fix this prolem. Please do not send this kind of commits again.
> 

Let's think about what's our goal first.

- 1) Fix the panic[1] and only support PAGE_SIZE MR
- 2) support PAGE_SIZE aligned MR
- 3) support any page_size MR.

I'm sorry i'm not familiar with the linux MM subsystem. It seem it's safe/correct to access
address/memory across pages start from the return of kmap_loca_page(page).
In other words, 2) is already native supported, right?

I get totally confused now.



> Zhu Yanjun
> 
>>
>> [1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@xxxxxxxxxxxxxx/T/
>>
>> Li Zhijian (6):
>>    RDMA/rxe: RDMA/rxe: don't allow registering !PAGE_SIZE mr
>>    RDMA/rxe: set RXE_PAGE_SIZE_CAP to PAGE_SIZE
>>    RDMA/rxe: remove unused rxe_mr.page_shift
>>    RDMA/rxe: Use PAGE_SIZE and PAGE_SHIFT to extract address from
>>      page_list
>>    RDMA/rxe: cleanup rxe_mr.{page_size,page_shift}
>>    RDMA/rxe: Support PAGE_SIZE aligned MR
>>
>>   drivers/infiniband/sw/rxe/rxe_mr.c    | 80 ++++++++++++++++-----------
>>   drivers/infiniband/sw/rxe/rxe_param.h |  2 +-
>>   drivers/infiniband/sw/rxe/rxe_verbs.h |  9 ---
>>   3 files changed, 48 insertions(+), 43 deletions(-)
>>
>