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charset="us-ascii" Content-ID: <2608ADBADE66244CAF93015265B4523A@eurprd05.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: Mellanox.com X-MS-Exchange-CrossTenant-Network-Message-Id: 141dbce2-fcb6-438c-3fab-08d686e7e8e6 X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Jan 2019 19:19:52.2454 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-id: a652971c-7d2e-4d9b-a6a4-d149256f461b X-MS-Exchange-Transport-CrossTenantHeadersStamped: DBBPR05MB6395 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Jan 30, 2019 at 11:13:11AM -0700, Logan Gunthorpe wrote: >=20 >=20 > On 2019-01-30 10:44 a.m., Jason Gunthorpe wrote: > > I don't see why a special case with a VMA is really that different. >=20 > Well one *really* big difference is the VMA changes necessarily expose > specialized new functionality to userspace which has to be supported > forever and may be difficult to change.=20 The only user change here is that more things will succeed when creating RDMA MRs (and vice versa to GPU). I don't think this restricts the kernel implementation at all, unless we intend to remove P2P entirely.. Jason