Messages in this thread | | | Date | Thu, 20 Jan 2022 19:19:51 +0100 | Subject | Re: [PATCH] mm: reuse the unshared swapcache page in do_wp_page | From | David Hildenbrand <> |
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>> Sounds good? At least to me. If only swap/migration entries wouldn't be >> harder to handle than I'd wish, that's why it's taking a little and will >> take a little longer. > > Thanks for the quick response. I would have to see the logic to set/clear > PageAnonExclusive to fully understand how things are handled. >
I'll let you know as soon as I have something. I'll most probably share a document explaining the design first.
> BTW, I just saw this patch form PeterZ [1] that seems to be related, as > it deals with changing protection on pinned pages.
Unfortunately the use of page_maybe_dma_pinned() is racy, as we can race with GUP fast. It's a problem for vmscan which currently relies on it for correctness. For migration, it might be good enough as we should fail later when trying to freeze the refcount.
> > > [1] https://lore.kernel.org/linux-mm/20220120160822.666778608@infradead.org/ >
-- Thanks,
David / dhildenb
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