On 9/9/26 15:35, Greg Kroah-Hartman wrote:
> On Wed, Sep 09, 2026 at 06:42:03PM +0800, Li Wang wrote:
>> Hi Greg,
>> Thanks for the review!
>>
>>>
>>> That's not really needed in a changelog text, it could be in the 0/X
>>> patch :)
>>>
>> Sorry for the clutter. I will move most of them into the 0/X patch in v2.
>>
>>> Anyway, you didn't cc: the io_uring list, why?
>>>
>> `scripts/get_maintainer.pl` didn't output the io_uring mailing list, likely
>> because this patch doesn't directly touch the io_uring codebase itself. It
>> only
>> enables remapping GPU memory buffers to CPU virtual addresses, which can
>> then be
>> consumed via standard io_uring APIs.
>>
>> I've added [email protected] to CC for this reply and will keep it in
>> v2.
>
> Great, as you are using that as the api, there might be some parts that
> will need to be reviewed by them.
>
>>> Nor why "fgds" is the name, that's going to be hard to remember, does it
>>> stand for something?
>>>
>> "FGDS" stands for Fast GPUDirect Storage. GPUDirect Storage (GDS) is
>> NVIDIA's
>> technology enabling direct I/O between GPU memory and files on NVMe,
>> widely used in LLM workloads to bypass CPU overhead.
>
> That's nvidia's specific solution, but this works on other devices,
> right? Or just for that one platform?
That was nvidia's specific and very hacky out of tree solution which as far as
I know is pretty much abandoned everywhere.
AMD came up with something similar, but all those approaches are so
fundamentally broken that we didn't even considered upstreaming it.
> And you are using this as a "bypass" for the normal accel subsystem,
> shouldn't this be part of that subsystem instead of a custom user/kernel
> api like you are creating here?
As far as I know there is a patch set under review and even already partially
merged which enables exactly that functionality as general feature for DMA-buf
which is vendor independent and should at least in theory work with all drivers.
I'm really surprised that somebody is still working on the vendor specific
stuff.
Regards,
Christian.
>
> thanks,
>
> greg k-h
