From mboxrd@z Thu Jan  1 00:00:00 1970
From: Doug Ledford <dledford@redhat.com>
Subject: Re: [LSF/MM TOPIC] Discuss least bad options for resolving
 longterm-GUP usage by RDMA
Date: Wed, 06 Feb 2019 15:16:02 -0500
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To: Matthew Wilcox <willy@infradead.org>, Christopher Lameter <cl@linux.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>, Jan Kara <jack@suse.cz>, Ira Weiny <ira.weiny@intel.com>, lsf-pc@lists.linux-foundation.org, linux-rdma@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, John Hubbard <jhubbard@nvidia.com>, Jerome Glisse <jglisse@redhat.com>, Dan Williams <dan.j.williams@intel.com>, Dave Chinner <david@fromorbit.com>, Michal Hocko <mhocko@kernel.org>
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On Wed, 2019-02-06 at 11:40 -0800, Matthew Wilcox wrote:
> On Wed, Feb 06, 2019 at 07:16:21PM +0000, Christopher Lameter wrote:
> >=20
> > though? If we only allow this use case then we may not have to worry ab=
out
> > long term GUP because DAX mapped files will stay in the physical locati=
on
> > regardless.
>=20
> ... except for truncate.  And now that I think about it, there was a
> desire to support hot-unplug which also needed revoke.

We already support hot unplug of RDMA devices.  But it is extreme.  How
does hot unplug deal with a program running from the device (something
that would have returned ETXTBSY)?

--=20
Doug Ledford <dledford@redhat.com>
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