On Tue, May 07, 2024 at 06:25:52PM +0100, Pavel Begunkov wrote: > On 5/7/24 17:48, Jason Gunthorpe wrote: > > On Tue, May 07, 2024 at 09:42:05AM -0700, Mina Almasry wrote: > > > > > 1. Align with devmem TCP to use udmabuf for your io_uring memory. I > > > think in the past you said it's a uapi you don't link but in the face > > > of this pushback you may want to reconsider. > > > > dmabuf does not force a uapi, you can acquire your pages however you > > want and wrap them up in a dmabuf. No uapi at all. > > > > The point is that dmabuf already provides ops that do basically what > > is needed here. We don't need ops calling ops just because dmabuf's > > ops are not understsood or not perfect. Fixup dmabuf. > > Those ops, for example, are used to efficiently return used buffers > back to the kernel, which is uapi, I don't see how dmabuf can be > fixed up to cover it. Sure, but that doesn't mean you can't use dma buf for the other parts of the flow. The per-page lifetime is a different topic than the refcounting and access of the entire bulk of memory. Jason
