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	Tue, 13 Aug 2024 05:41:20 +0000
Date: Mon, 12 Aug 2024 22:41:20 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Christoph Hellwig <hch@infradead.org>,
	Martin Oliveira <martin.oliveira@eideticom.com>,
	linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	Artemy Kovalyov <artemyko@nvidia.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Leon Romanovsky <leon@kernel.org>,
	Logan Gunthorpe <logang@deltatee.com>,
	Michael Guralnik <michaelgur@nvidia.com>,
	Mike Marciniszyn <mike.marciniszyn@intel.com>,
	Shiraz Saleem <shiraz.saleem@intel.com>, Tejun Heo <tj@kernel.org>,
	John Hubbard <jhubbard@nvidia.com>,
	Dan Williams <dan.j.williams@intel.com>,
	David Sloan <david.sloan@eideticom.com>
Subject: Re: [PATCH v5 3/4] mm/gup: allow FOLL_LONGTERM & FOLL_PCI_P2PDMA
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On Mon, Aug 12, 2024 at 08:12:49PM -0300, Jason Gunthorpe wrote:
> > This is unfortunately not really minor unless we have a well documented
> > way to force this :(
> 
> It is not that different from blocking driver unbind while FDs are
> open which a lot of places do in various ways?

Where do we block driver unbind with an open resource?  The whole
concept is that open resources will pin the in-memory object (and
modulo for a modular driver), but never an unbind or hardware
unplug, of which unbind really just is a simulation.