Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Yicong Yang <yangyicong@huawei.com>]

Hi Barry,

On 2025/8/4 12:47, Barry Song wrote:
> On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>>
>> On 24.07.2025 11:42, Barry Song wrote:
>>> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
>>>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>>>> The padding field in the structure was previously reserved to
>>>>>> maintain a stable interface for potential new fields, ensuring
>>>>>> compatibility with user-space shared data structures.
>>>>>> However,it was accidentally removed by tiantao in a prior commit,
>>>>>> which may lead to incompatibility between user space and the kernel.
>>>>>>
>>>>>> This patch reinstates the padding to restore the original structure
>>>>>> layout and preserve compatibility.
>>>>>>
>>>>>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
>>>>>> Cc: stable@vger.kernel.org
>>>>>> Acked-by: Barry Song <baohua@kernel.org>
>>>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>>>>> I don’t think these two patches should be part of the same series. This
>>>>> one is a bug fix and should be handled separately—ideally picked up on
>>>>> its own and backported to stable.
>>>>>
>>>>> Also, the subject should not say "Add"—it should be "Restore". I assume
>>>>> Marek can handle it?
>>> ...
>>>> Ok, I will send a new version to fix it.
>>> If Marek can help fix it while picking it up into the dma-mapping tree, you
>>> might not need to send a new version.
>>>
>>> Honestly, I hope this gets merged soon—it feels like it's been
>>> overdue for quite a while.
>>
>> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
>> will take it after this merge window.
> 
> Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
> for quite a while, likely he moved to another company some time ago. It looks
> like Yicong has volunteered to take this on:
> 
> https://lkml.indiana.edu/2408.1/08865.html
> 
> I'm not sure if that's still the case. If it is, would Yicong be able to
> resend the email with my ack?
> 

thanks for reminding. I think currently Qinxin is more suitable to help with this.
she's working on the smmu stuffs and help look after this benchmark tool internally
for some time :)

Maybe she can help along with you (ack the fact that you're always helping to review
the codes) if it's ok with you.

Thanks.