On Wed, Mar 30, 2022 at 06:04:08AM -0700, Christoph Hellwig wrote: > On Wed, Mar 30, 2022 at 09:00:46AM -0400, Johannes Weiner wrote: > > If you want type distinction, we should move it all into MM code, like > > Christoph is saying. Were swap code handles anon refaults and the page > > cache code handles file refaults. This would be my preferred layering, > > and my original patch did that: https://lkml.org/lkml/2019/7/22/1070. > > FYI, I started redoing that version and I think with all the cleanups > to filemap.c and the readahead code this can be done fairly nicely now: > > http://git.infradead.org/users/hch/block.git/commitdiff/666abb29c6db870d3941acc5ac19e83fbc72cfd4 Yes, it's definitely much nicer now with the MM instantiating the pages for ->readpage(s). But AFAICS this breaks compressed btrfs (and erofs?) because those still do additional add_to_page_cache_lru() and bio submissions.
