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charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 21, 2020 at 11:17 PM Peter Xu wrote: > > (Commit message collected from Jason Gunthorpe) > > Reduce the chance of false positive from page_maybe_dma_pinned() by keeping > track if the mm_struct has ever been used with pin_user_pages(). mm_structs > that have never been passed to pin_user_pages() cannot have a positive > page_maybe_dma_pinned() by definition. There are some caveats here, right? E.g. this isn't necessarily true for pagecache pages, I think?