On Fri, 13 Oct 2017, Michal Hocko wrote: > On Fri 13-10-17 10:20:06, Cristopher Lameter wrote: > > On Fri, 13 Oct 2017, Michal Hocko wrote: > [...] > > > I am not really convinced this is a good interface. You are basically > > > trying to bypass virtual memory abstraction and that is quite > > > contradicting the mmap API to me. > > > > This is a standardized posix interface as described in our presentation at > > the plumbers conference. See the presentation on contiguous allocations. > > Are you trying to desing a generic interface with a very specific and HW > dependent usecase in mind?
There is a generic posix interface that could we used for a variety of specific hardware dependent use cases. > > The contiguous allocations are particularly useful for the RDMA API which > > allows registering user space memory with devices. > > then make those devices expose an implementation of an mmap which does > that. You would get both a proper access control (via fd), accounting > and others. There are numerous RDMA devices that would all need the mmap implementation. And this covers only the needs of one subsystem. There are other use cases.
