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In the memdesc > future, struct page has no members (you could store a small amount of > information in it, but I'm not willing to commit to more than a few bits). > Shouldn't we change brd to use folios? Once we do that, this will not be a problem any more right? Hannes even had patches around it long time back [1] > brd doesn't use anything else from struct page, as far as I can tell. > It just calls kmap_atomic() / __free_page() / flush_dcache_page() (and > it doesn't need to call flush_dcache_page() because you can't mmap the > pages in the brd's array). > > Now if you have plans to, eg, support page migration, you're going to need > a bit more infrastructure than just allocating pages, but for what you > have at the moment, just removing the debugging checks that page->index == > idx would make you entirely compatible with the memdesc future. > > Any problem with that? [1] https://lore.kernel.org/linux-block/20230306120127.21375-2-hare@suse.de/