On Tue, Jun 24, 2025 at 5:36 AM Bernd Schubert <bernd@xxxxxxxxxxx> wrote: > > > > On 6/20/25 03:39, xiaobing.li wrote: > > On Wed, Jun 18, 2025 at 09:30:51PM -0600, Keith Busch wrote: > >> On Wed, Jun 18, 2025 at 03:13:41PM +0200, Bernd Schubert wrote: > >>> On 6/18/25 12:54, xiaobing.li wrote: > >>>> > >>>> Hi Bernd, > >>>> > >>>> Do you have any plans to add zero copy solution? We are interested in > >>>> FUSE's zero copy solution and conducting research in code. > >>>> If you have no plans in this regard for the time being, we intend to > >>>> submit our solution. > >>> > >>> Hi Xiobing, > >>> > >>> Keith (add to CC) did some work for that in ublk and also planned to > >>> work on that for fuse (or a colleague). Maybe Keith could > >>> give an update. > >> > >> I was initially asked to implement a similar solution that ublk uses for > >> zero-copy, but the requirements changed such that it won't work. The > >> ublk server can't directly access the zero-copy buffers. It can only > >> indirectly refer to it with an io_ring registered buffer index, which is > >> fine my ublk use case, but the fuse server that I was trying to > >> enable does in fact need to directly access that data. > >> > >> My colleauge had been working a solution, but it required shared memory > >> between the application and the fuse server, and therefore cooperation > >> between them, which is rather limiting. It's still on his to-do list, > >> but I don't think it's a high priority at the moment. If you have > >> something in the works, please feel free to share it when you're ready, > >> and I would be interested to review. > > > > Hi Bernd and Keith, > > > > In fact, our current idea is to implement a similar solution that ublk uses > > for zero-copy. If this can really further improve the performance of FUSE, > > then I think it is worth trying. > > By the way, if it is convenient, could you tell me what was the original > > motivation for adding io_uring, or why you want to improve the performance > > of FUSE and what you want to apply it to? > > At DDN we have mainly a network file system using fuse - the faster it > runs the better. But we need access to the data for erasure, > compression, etc. Zero-copy would be great, but I think it is BTW, the current ublk io_uring zero copy may be extended with ebpf uring_op for supporting standard compression & checksum too, and Android has similar requirements too: https://lpc.events/event/18/contributions/1710/attachments/1440/3070/LPC2024_ublk_zero_copy.pdf Thanks, Ming Lei
