From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory Date: Wed, 19 Apr 2017 11:13:15 +1000 Message-ID: <1492564395.25766.120.camel@kernel.crashing.org> References: <1492381396.25766.43.camel@kernel.crashing.org> <20170418164557.GA7181@obsidianresearch.com> <20170418180020.GE7181@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170418180020.GE7181-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Jason Gunthorpe , Dan Williams Cc: Jens Axboe , "James E.J. Bottomley" , "Martin K. Petersen" , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Steve Wise , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Keith Busch , Jerome Glisse , Bjorn Helgaas , linux-scsi , linux-nvdimm , Max Gurtovoy , Christoph Hellwig List-Id: linux-nvdimm@lists.01.org T24gVHVlLCAyMDE3LTA0LTE4IGF0IDEyOjAwIC0wNjAwLCBKYXNvbiBHdW50aG9ycGUgd3JvdGU6 Cj4gLSBBbGwgcGxhdGZvcm1zIGNhbiBzdWNjZWVkIGlmIHRoZSBQQ0kgZGV2aWNlcyBhcmUgdW5k ZXIgdGhlIHNhbWUKPiDCoCAnc2VnbWVudCcsIGJ1dCB3aGVyZSBzZWdtZW50cyBiZWdpbiBpcyBz b21ld2hhdCBwbGF0Zm9ybSBzcGVjaWZpYwo+IMKgIGtub3dsZWRnZS4gKHRoaXMgaXMgJ3NhbWUg c3dpdGNoJyBpZGVhIExvZ2FuIGhhcyB0YWxrZWQgYWJvdXQpCgpXZSBhbHNvIG5lZWQgdG8gYmUg Y2FyZWZ1bCB3aGV0aGVyIFAyUCBpcyBlbmFibGVkIGluIHRoZSBzd2l0Y2gKb3Igbm90LgoKQ2hl ZXJzLApCZW4uCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f XwpMaW51eC1udmRpbW0gbWFpbGluZyBsaXN0CkxpbnV4LW52ZGltbUBsaXN0cy4wMS5vcmcKaHR0 cHM6Ly9saXN0cy4wMS5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1udmRpbW0K From mboxrd@z Thu Jan 1 00:00:00 1970 From: benh@kernel.crashing.org (Benjamin Herrenschmidt) Date: Wed, 19 Apr 2017 11:13:15 +1000 Subject: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory In-Reply-To: <20170418180020.GE7181@obsidianresearch.com> References: <1492381396.25766.43.camel@kernel.crashing.org> <20170418164557.GA7181@obsidianresearch.com> <20170418180020.GE7181@obsidianresearch.com> Message-ID: <1492564395.25766.120.camel@kernel.crashing.org> On Tue, 2017-04-18@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. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: 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" Mime-Version: 1.0 List-ID: 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.