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Date:   Mon, 4 Oct 2021 10:27:59 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>
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        Alistair Popple <apopple@nvidia.com>,
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Subject: Re: [PATCH v3 19/20] PCI/P2PDMA: introduce pci_mmap_p2pmem()
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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