On Mon, Nov 9, 2020 at 8:47 AM Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote: > > > > On 2020-11-09 2:12 a.m., Christoph Hellwig wrote: > > On Fri, Nov 06, 2020 at 10:00:25AM -0700, Logan Gunthorpe wrote: > >> We make use of the top bit of the dma_length to indicate a P2PDMA > >> segment. > > > > I don't think "we" can. There is nothing limiting the size of a SGL > > segment. > > Yes, I expected this would be the unacceptable part. Any alternative ideas? Why is the SG_P2PDMA_FLAG needed as compared to checking the SGL segment-pages for is_pci_p2pdma_page()?
