On Mon, Feb 28, 2022 at 04:52:52PM +0800, Xiaoguang Wang wrote: > > hi Bodo, > > > Liu, > > > > generally I like ideas to speed up tcmu. > > > > OTOH, since Andy Grover implemented tcmu based on uio device, we are > > restricted to what uio offers. With today's knowledge I think we would > > not use the uio device in tcmu again, but switching away from uio now > > would break existing userspace SW. > Yeah, it will have much work if deciding to switch away from uio. > I came up with a hacky or crazy idea :) what about we create a new file > in tcmu_open() by anon_inode_getfile_secure(), and export this fd by > tcmu mail box, we can do ioctl() on this new file, then uio framework > won't be touched... No new ioctls please. That is creating a new user/kernel api that you must support for the next 20+ years. Please do not do that. thanks, greg k-h
