From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161930AbeCAVLu (ORCPT ); Thu, 1 Mar 2018 16:11:50 -0500 Received: from ale.deltatee.com ([207.54.116.67]:38568 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161764AbeCAVLq (ORCPT ); Thu, 1 Mar 2018 16:11:46 -0500 To: benh@au1.ibm.com, Dan Williams Cc: Linux Kernel Mailing List , linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma , linux-nvdimm , linux-block@vger.kernel.org, Stephen Bates , Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Alex Williamson , Oliver OHalloran References: <20180228234006.21093-1-logang@deltatee.com> <1519876489.4592.3.camel@kernel.crashing.org> <1519876569.4592.4.camel@au1.ibm.com> <1519938210.4592.30.camel@au1.ibm.com> From: Logan Gunthorpe Message-ID: <1de70207-40ce-29f0-6093-337112852475@deltatee.com> Date: Thu, 1 Mar 2018 14:11:34 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1519938210.4592.30.camel@au1.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: oliveroh@au1.ibm.com, alex.williamson@redhat.com, jglisse@redhat.com, maxg@mellanox.com, jgg@mellanox.com, bhelgaas@google.com, sagi@grimberg.me, keith.busch@intel.com, axboe@kernel.dk, hch@lst.de, sbates@raithlin.com, linux-block@vger.kernel.org, linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dan.j.williams@intel.com, benh@au1.ibm.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/03/18 02:03 PM, Benjamin Herrenschmidt wrote: > However, what happens if anything calls page_address() on them ? Some > DMA ops do that for example, or some devices might ... Although we could probably work around it with some pain, we rely on page_address() and virt_to_phys(), etc to work on these pages. So on x86, yes, it makes it into the linear mapping. Logan