Re: [PATCH v3 19/20] PCI/P2PDMA: introduce pci_mmap_p2pmem()

[Jason Gunthorpe]

On Mon, Oct 04, 2021 at 03:22:22PM +0200, Christian König wrote:

> That use case is completely unrelated to GUP and when this doesn't work we
> have quite a problem.

My read is that unmap_mapping_range() guarentees the physical TLB
hardware is serialized across all CPUs upon return.

It also guarentees GUP slow is serialized due to the page table
spinlocks.

Jason