Re: [PATCH v3 00/20] Userspace P2PDMA with O_DIRECT NVMe devices

[Logan Gunthorpe]

On 2021-09-29 5:21 p.m., Jason Gunthorpe wrote:
> On Wed, Sep 29, 2021 at 03:50:02PM -0600, Logan Gunthorpe wrote:
>>
>>
>> On 2021-09-28 2:02 p.m., Jason Gunthorpe wrote:
>>> On Thu, Sep 16, 2021 at 05:40:40PM -0600, Logan Gunthorpe wrote:
>>>> Hi,
>>>>
>>>> This patchset continues my work to add userspace P2PDMA access using
>>>> O_DIRECT NVMe devices. My last posting[1] just included the first 13
>>>> patches in this series, but the early P2PDMA cleanup and map_sg error
>>>> changes from that series have been merged into v5.15-rc1. To address
>>>> concerns that that series did not add any new functionality, I've added
>>>> back the userspcae functionality from the original RFC[2] (but improved
>>>> based on the original feedback).
>>>
>>> I really think this is the best series yet, it really looks nice
>>> overall. I know the sg flag was a bit of a debate at the start, but it
>>> serves an undeniable purpose and the resulting standard DMA APIs 'just
>>> working' is really clean.
>>
>> Actually, so far, nobody has said anything negative about using the SG flag.
>>
>>> There is more possible here, we could also pass the new GUP flag in the
>>> ib_umem code..
>>
>> Yes, that would be very useful.
> 
> You might actually prefer to do that then the bio changes to get the
> infrastructur merged as it seems less "core"

I'm a little bit more concerned about my patch set growing too large.
It's already at 20 patches and I think I'll need to add a couple more
based on the feedback you've already provided. So I'm leaning toward
pushing more functionality as future work.

Logan