Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758885AbdDSBOp (ORCPT ); Tue, 18 Apr 2017 21:14:45 -0400 Received: from gate.crashing.org ([63.228.1.57]:59146 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757806AbdDSBOn (ORCPT ); Tue, 18 Apr 2017 21:14:43 -0400 Message-ID: <1492564395.25766.120.camel@kernel.crashing.org> Subject: Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory From: Benjamin Herrenschmidt To: Jason Gunthorpe , Dan Williams Cc: Logan Gunthorpe , Bjorn Helgaas , Christoph Hellwig , Sagi Grimberg , "James E.J. Bottomley" , "Martin K. Petersen" , Jens Axboe , Steve Wise , Stephen Bates , Max Gurtovoy , Keith Busch , linux-pci@vger.kernel.org, linux-scsi , linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm , "linux-kernel@vger.kernel.org" , Jerome Glisse Date: Wed, 19 Apr 2017 11:13:15 +1000 In-Reply-To: <20170418180020.GE7181@obsidianresearch.com> References: <1492381396.25766.43.camel@kernel.crashing.org> <20170418164557.GA7181@obsidianresearch.com> <20170418180020.GE7181@obsidianresearch.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-1.fc25) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 352 Lines: 10 On Tue, 2017-04-18 at 12:00 -0600, Jason Gunthorpe wrote: > - All platforms can succeed if the PCI devices are under the same >   'segment', but where segments begin is somewhat platform specific >   knowledge. (this is 'same switch' idea Logan has talked about) We also need to be careful whether P2P is enabled in the switch or not. Cheers, Ben.