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By the end of Page2025, plain pages have a refcount, > but folios/slabs/ptdesc/etc set the page->_refcount to 0. Reading this again, I didn't quite get this till now. Maybe it is worth adding this detail to the wikki. In this case, what are "plain pages"? One I can think of is naked calls to alloc_page*(), which I see often used in place of kmalloc(PAGE_SIZE), do you imagine a project to favour kmalloc instead? Jason