From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ale.deltatee.com (ale.deltatee.com [207.54.116.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5700B20946068 for ; Fri, 4 May 2018 08:52:57 -0700 (PDT) References: <20180423233046.21476-1-logang@deltatee.com> <805645c1-ea40-2e57-88eb-5dd34e579b2e@deltatee.com> <3e4e0126-f444-8d88-6793-b5eb97c61f76@amd.com> <38d866cf-f7b4-7118-d737-5a5dcd9f3784@amd.com> <2d59aa02-f2fa-bd88-1b6c-923117a6ad28@deltatee.com> <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> From: Logan Gunthorpe Message-ID: Date: Fri, 4 May 2018 09:52:26 -0600 MIME-Version: 1.0 In-Reply-To: <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> Content-Language: en-US Subject: Re: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-block@vger.kernel.org Cc: Jens Axboe , Benjamin Herrenschmidt , Alex Williamson , Keith Busch , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-ID: CgpPbiAwNC8wNS8xOCAwODoyNyBBTSwgQ2hyaXN0aWFuIEvDtm5pZyB3cm90ZToKPiBBcmUgeW91 IHN1cmUgdGhhdCB0aGlzIGlzIG1vcmUgY29udmVuaWVudD8gQXQgbGVhc3Qgb24gZmlyc3QgZ2xh bmNlIGl0IAo+IGZlZWxzIG92ZXJseSBjb21wbGljYXRlZC4KPiAKPiBJIG1lYW4gd2hhdCdzIHRo ZSBkaWZmZXJlbmNlIGJldHdlZW4gdGhlIHR3byBhcHByb2FjaGVzPwo+IAo+ICDCoMKgwqAgc3Vt ID0gcGNpX3AycGRtYV9kaXN0YW5jZSh0YXJnZXQsIFtBLCBCLCBDLCB0YXJnZXRdKTsKPiAKPiBh bmQKPiAKPiAgwqDCoMKgIHN1bSA9IHBjaV9wMnBkbWFfZGlzdGFuY2UodGFyZ2V0LCBBKTsKPiAg wqDCoMKgIHN1bSArPSBwY2lfcDJwZG1hX2Rpc3RhbmNlKHRhcmdldCwgQik7Cj4gIMKgwqDCoCBz dW0gKz0gcGNpX3AycGRtYV9kaXN0YW5jZSh0YXJnZXQsIEMpOwoKV2VsbCwgaXQncyBtb3JlIGZv ciBjb25zaXN0ZW5jeSB3aXRoIHRoZSBwY2lfcDJwZG1hX2ZpbmQoKSB3aGljaCBoYXMgdG8KdGFr ZSBhIGxpc3Qgb2YgZGV2aWNlcyB0byBmaW5kIGEgcmVzb3VyY2Ugd2hpY2ggbWF0Y2hlcyBhbGwg b2YgdGhlbS4KKFlvdSBjYW4ndCB1c2UgbXVsdGlwbGUgY2FsbHMgaW4gdGhhdCBjYXNlIGJlY2F1 c2UgYWxsIHRoZSBkZXZpY2VzIGluCnRoZSBsaXN0IG1pZ2h0IG5vdCBoYXZlIHRoZSBzYW1lIHNl dCBvZiBjb21wYXRpYmxlIHByb3ZpZGVycy4pIFRoYXQgd2F5CndlIGNhbiB1c2UgdGhlIHNhbWUg bGlzdCB0byBjaGVjayB0aGUgZGlzdGFuY2UgKHdoZW4gdGhlIHVzZXIgc3BlY2lmaWVzCmEgZGV2 aWNlKSBhcyB3ZSBkbyB0byBmaW5kIGEgY29tcGF0aWJsZSBkZXZpY2UgKHdoZW4gdGhlIHVzZXIg d2FudHMgdG8KYXV0b21hdGljYWxseSBmaW5kIG9uZS4KCkxvZ2FuCl9fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCkxpbnV4LW52ZGltbSBtYWlsaW5nIGxpc3QK TGludXgtbnZkaW1tQGxpc3RzLjAxLm9yZwpodHRwczovL2xpc3RzLjAxLm9yZy9tYWlsbWFuL2xp c3RpbmZvL2xpbnV4LW52ZGltbQo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-block@vger.kernel.org Cc: Stephen Bates , Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , Dan Williams , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Benjamin Herrenschmidt , Alex Williamson References: <20180423233046.21476-1-logang@deltatee.com> <805645c1-ea40-2e57-88eb-5dd34e579b2e@deltatee.com> <3e4e0126-f444-8d88-6793-b5eb97c61f76@amd.com> <38d866cf-f7b4-7118-d737-5a5dcd9f3784@amd.com> <2d59aa02-f2fa-bd88-1b6c-923117a6ad28@deltatee.com> <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> From: Logan Gunthorpe Message-ID: Date: Fri, 4 May 2018 09:52:26 -0600 MIME-Version: 1.0 In-Reply-To: <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> Content-Type: text/plain; charset=utf-8 Subject: Re: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory List-ID: On 04/05/18 08:27 AM, Christian König wrote: > Are you sure that this is more convenient? At least on first glance it > feels overly complicated. > > I mean what's the difference between the two approaches? > >     sum = pci_p2pdma_distance(target, [A, B, C, target]); > > and > >     sum = pci_p2pdma_distance(target, A); >     sum += pci_p2pdma_distance(target, B); >     sum += pci_p2pdma_distance(target, C); Well, it's more for consistency with the pci_p2pdma_find() which has to take a list of devices to find a resource which matches all of them. (You can't use multiple calls in that case because all the devices in the list might not have the same set of compatible providers.) That way we can use the same list to check the distance (when the user specifies a device) as we do to find a compatible device (when the user wants to automatically find one. Logan From mboxrd@z Thu Jan 1 00:00:00 1970 From: Logan Gunthorpe Subject: Re: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory Date: Fri, 4 May 2018 09:52:26 -0600 Message-ID: References: <20180423233046.21476-1-logang@deltatee.com> <805645c1-ea40-2e57-88eb-5dd34e579b2e@deltatee.com> <3e4e0126-f444-8d88-6793-b5eb97c61f76@amd.com> <38d866cf-f7b4-7118-d737-5a5dcd9f3784@amd.com> <2d59aa02-f2fa-bd88-1b6c-923117a6ad28@deltatee.com> <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <17e7bc28-f499-c7f7-f91a-9f6778de5fd3-5C7GfCeVMHo@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Jens Axboe , Benjamin Herrenschmidt , Alex Williamson , Keith Busch , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-Id: linux-rdma@vger.kernel.org CgpPbiAwNC8wNS8xOCAwODoyNyBBTSwgQ2hyaXN0aWFuIEvDtm5pZyB3cm90ZToKPiBBcmUgeW91 IHN1cmUgdGhhdCB0aGlzIGlzIG1vcmUgY29udmVuaWVudD8gQXQgbGVhc3Qgb24gZmlyc3QgZ2xh bmNlIGl0IAo+IGZlZWxzIG92ZXJseSBjb21wbGljYXRlZC4KPiAKPiBJIG1lYW4gd2hhdCdzIHRo ZSBkaWZmZXJlbmNlIGJldHdlZW4gdGhlIHR3byBhcHByb2FjaGVzPwo+IAo+ICDCoMKgwqAgc3Vt ID0gcGNpX3AycGRtYV9kaXN0YW5jZSh0YXJnZXQsIFtBLCBCLCBDLCB0YXJnZXRdKTsKPiAKPiBh bmQKPiAKPiAgwqDCoMKgIHN1bSA9IHBjaV9wMnBkbWFfZGlzdGFuY2UodGFyZ2V0LCBBKTsKPiAg wqDCoMKgIHN1bSArPSBwY2lfcDJwZG1hX2Rpc3RhbmNlKHRhcmdldCwgQik7Cj4gIMKgwqDCoCBz dW0gKz0gcGNpX3AycGRtYV9kaXN0YW5jZSh0YXJnZXQsIEMpOwoKV2VsbCwgaXQncyBtb3JlIGZv ciBjb25zaXN0ZW5jeSB3aXRoIHRoZSBwY2lfcDJwZG1hX2ZpbmQoKSB3aGljaCBoYXMgdG8KdGFr ZSBhIGxpc3Qgb2YgZGV2aWNlcyB0byBmaW5kIGEgcmVzb3VyY2Ugd2hpY2ggbWF0Y2hlcyBhbGwg b2YgdGhlbS4KKFlvdSBjYW4ndCB1c2UgbXVsdGlwbGUgY2FsbHMgaW4gdGhhdCBjYXNlIGJlY2F1 c2UgYWxsIHRoZSBkZXZpY2VzIGluCnRoZSBsaXN0IG1pZ2h0IG5vdCBoYXZlIHRoZSBzYW1lIHNl dCBvZiBjb21wYXRpYmxlIHByb3ZpZGVycy4pIFRoYXQgd2F5CndlIGNhbiB1c2UgdGhlIHNhbWUg bGlzdCB0byBjaGVjayB0aGUgZGlzdGFuY2UgKHdoZW4gdGhlIHVzZXIgc3BlY2lmaWVzCmEgZGV2 aWNlKSBhcyB3ZSBkbyB0byBmaW5kIGEgY29tcGF0aWJsZSBkZXZpY2UgKHdoZW4gdGhlIHVzZXIg d2FudHMgdG8KYXV0b21hdGljYWxseSBmaW5kIG9uZS4KCkxvZ2FuCl9fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCkxpbnV4LW52ZGltbSBtYWlsaW5nIGxpc3QK TGludXgtbnZkaW1tQGxpc3RzLjAxLm9yZwpodHRwczovL2xpc3RzLjAxLm9yZy9tYWlsbWFuL2xp c3RpbmZvL2xpbnV4LW52ZGltbQo= From mboxrd@z Thu Jan 1 00:00:00 1970 From: logang@deltatee.com (Logan Gunthorpe) Date: Fri, 4 May 2018 09:52:26 -0600 Subject: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory In-Reply-To: <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> References: <20180423233046.21476-1-logang@deltatee.com> <805645c1-ea40-2e57-88eb-5dd34e579b2e@deltatee.com> <3e4e0126-f444-8d88-6793-b5eb97c61f76@amd.com> <38d866cf-f7b4-7118-d737-5a5dcd9f3784@amd.com> <2d59aa02-f2fa-bd88-1b6c-923117a6ad28@deltatee.com> <17e7bc28-f499-c7f7-f91a-9f6778de5fd3@amd.com> Message-ID: On 04/05/18 08:27 AM, Christian K?nig wrote: > Are you sure that this is more convenient? At least on first glance it > feels overly complicated. > > I mean what's the difference between the two approaches? > > ??? sum = pci_p2pdma_distance(target, [A, B, C, target]); > > and > > ??? sum = pci_p2pdma_distance(target, A); > ??? sum += pci_p2pdma_distance(target, B); > ??? sum += pci_p2pdma_distance(target, C); Well, it's more for consistency with the pci_p2pdma_find() which has to take a list of devices to find a resource which matches all of them. (You can't use multiple calls in that case because all the devices in the list might not have the same set of compatible providers.) That way we can use the same list to check the distance (when the user specifies a device) as we do to find a compatible device (when the user wants to automatically find one. Logan