On Thu, Sep 16, 2021 at 05:40:54PM -0600, Logan Gunthorpe wrote: > Callers that expect PCI P2PDMA pages can now set FOLL_PCI_P2PDMA to > allow obtaining P2PDMA pages. If a caller does not set this flag > and tries to map P2PDMA pages it will fail. > > This is implemented by adding a flag and a check to get_dev_pagemap(). I would like to see the get_dev_pagemap() deleted from GUP in the first place. Why isn't this just a simple check of the page->pgmap type after acquiring a valid page reference? See my prior note Jason