On Fri, Jan 21, 2022 at 10:33:58AM +0800, Shiyang Ruan wrote: > > > > But different question, how does this not conflict with: > > > > #define PAGE_MAPPING_ANON 0x1 > > > > in page-flags.h? > > Now we are treating dax pages, so I think its flags should be different from > normal page. In another word, PAGE_MAPPING_ANON is a flag of rmap mechanism > for normal page, it doesn't work for dax page. And now, we have dax rmap > for dax page. So, I think this two kinds of flags are supposed to be used > in different mechanisms and won't conflect. It just needs someone to use folio_test_anon in a place where a DAX folio can be passed. This probably should not happen, but we need to clearly document that. > > Either way I think this flag should move to page-flags.h and be > > integrated with the PAGE_MAPPING_FLAGS infrastucture. > > And that's why I keep them in this dax.c file. But that does not integrate it with the infrastructure. For people to debug things it needs to be next to PAGE_MAPPING_ANON and have documentation explaining why they are exclusive.