Messages in this thread | | | Date | Wed, 12 Jan 2022 12:31:10 +0100 | From | David Hildenbrand <> | Subject | Re: [PATCHv2 1/7] mm: Add support for unaccepted memory |
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> > Looking at stuff like this, I can't help but think that a: > > #define PageOffline PageUnaccepted > > and some other renaming would be a fine idea. I get that the Offline > bit can be reused, but I'm not sure that the "Offline" *naming* should > be reused. What you're doing here is logically distinct from existing > offlining.
Yes, or using a new pagetype bit to make the distinction clearer. Especially the function names like maybe_set_page_offline() et. Al are confusing IMHO. They are all about accepting unaccepted memory ... and should express that.
I assume PageOffline() will be set only on the first sub-page of a high-order PageBuddy() page, correct?
Then we'll have to monitor all PageOffline() users such that they can actually deal with PageBuddy() pages spanning *multiple* base pages for a PageBuddy() page. For now it's clear that if a page is PageOffline(), it cannot be PageBuddy() and cannot span more than one base page.
E.g., fs/proc/kcore.c:read_kcore() assumes that PageOffline() is set on individual base pages.
-- Thanks,
David / dhildenb
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