On 2021-12-21 2:06 a.m., Christoph Hellwig wrote: > On Wed, Nov 17, 2021 at 02:54:08PM -0700, Logan Gunthorpe wrote: >> When P2PDMA pages are passed to userspace, they will need to be >> reference counted properly and returned to their genalloc after their >> reference count returns to 1. This is accomplished with the existing >> DEV_PAGEMAP_OPS and the .page_free() operation. >> >> Change CONFIG_P2PDMA to select CONFIG_DEV_PAGEMAP_OPS and add >> MEMORY_DEVICE_PCI_P2PDMA to page_is_devmap_managed(), >> devmap_managed_enable_[put|get]() and free_devmap_managed_page(). > > Uuuh. We are trying hard to kill off this magic free at refcount 1 > behavior in the amdgpu device coherent series. We really should not > add more of this. Ah, ok. I found Ralph's patch that cleans this up and I can try to rebase this onto it for future postings until it gets merged. Your other comments I can address for the next time I post this series. Thanks for the review! Logan
