On Thu, Aug 31, 2023 at 12:32:38PM -0300, Jason Gunthorpe wrote: > The entry is variable sized, so it depends on what is stuffed in > it. For alot of common use cases, especially RDMA page lists, it will > be able to use an 8 byte entry. This is pretty much the most space > efficient it could be. How do you get away with a 8 byte entry for addr+len? > The primary alternative I see is a fixed 16 bytes/entry with a 64 bit > address and ~60 bit length + ~4 bits of flags. This is closer to bio, > simpler and faster, but makes the RDMA cases 2x bigger. That's what I'd expect. > With your direction I felt we could safely keep bio as it is and > cheaply make a fast DMA mapper for it. Provide something like this as > the 'kitchen sink' version for dmabuf/rdma/etc that are a little > different. So for the first version I see no need to change the bio_vec representation as part of this project, but at the same time the bio_vec representation causes problems for other reasons. So I want to change it anyway.
