Re: [RESEND PATCH v5 1/2] RDMA/rxe: Support RDMA Atomic Write operation

Jason Gunthorpe
2022-10-24T18:50:38Z

On Thu, Oct 20, 2022 at 09:25:46PM +0800, Yang, Xiao/杨 晓 wrote:
> On 2022/10/15 0:00, Jason Gunthorpe wrote:
> > People have been thinking of new uses for kmap, rxe still should be
> > calling it.
>
> Hi Jason,
>
> Thanks a lot for your reply.
> Could you tell me what is the new usage about kmap()?

New in-kernel memory protection schemes

> > The above just explains why it doesn't fail today, it doesn't excuse
> > the wrong usage.
>
> I wonder why we need to use kmap() in this case?
> I'm sorry to ask the stupid question.

It is the defined API to convert a struct page into an address the CPU
can access.

Jason