On Fri, 15 Feb 2019, Matthew Wilcox wrote: > > Since RDMA is something similar: Can we say that a file that is used for > > RDMA should not use the page cache? > > That makes no sense. The page cache is the standard synchronisation point > for filesystems and processes. The only problems come in for the things > which bypass the page cache like O_DIRECT and DAX. It makes a lot of sense since the filesystems play COW etc games with the pages and RDMA is very much like O_DIRECT in that the pages are modified directly under I/O. It also bypasses the page cache in case you have not noticed yet. Both filesysetms and RDMA acting on a page cache at the same time lead to the mess that we are trying to solve.
