search for: pci_alloc_p2pmem

...rence count as part of memunmap_pages()? My testing of [1] seems OK but I'm sure there are lots of cases I didn't test. MEMORY_DEVICE_PCI_P2PDMA: Struct pages are created in pci_p2pdma_add_resource() and represent device memory accessible by PCIe bar address space. Memory is allocated with pci_alloc_p2pmem() based on a byte length but the gen_pool_alloc_owner() call will allocate memory in a minimum of PAGE_SIZE units. Reference counting is +1 per *allocation* on the pgmap->ref reference count. Note that this is not +1 per page which is what put_page() expects. So currently, a get_page()/put_page(...

On Fri, Nov 06, 2020 at 01:26:50PM -0800, Ralph Campbell wrote: > > On 11/6/20 12:03 AM, Christoph Hellwig wrote: >> I hate the extra pin count magic here. IMHO we really need to finish >> off the series to get rid of the extra references on the ZONE_DEVICE >> pages first. > > First, thanks for the review comments. > > I don't like the extra refcount

From: Yonatan Maman <Ymaman at Nvidia.com> This patch series aims to enable Peer-to-Peer (P2P) DMA access in GPU-centric applications that utilize RDMA and private device pages. This enhancement is crucial for minimizing data transfer overhead by allowing the GPU to directly expose device private page data to devices such as NICs, eliminating the need to traverse system RAM, which is the