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 1E9BA21F6A6FD for ; Fri, 2 Mar 2018 14:18:37 -0800 (PST) References: <20180228234006.21093-1-logang@deltatee.com> <1519876489.4592.3.camel@kernel.crashing.org> <1519876569.4592.4.camel@au1.ibm.com> <1519936477.4592.23.camel@au1.ibm.com> <2079ba48-5ae5-5b44-cce1-8175712dd395@deltatee.com> <43ba615f-a6e1-9444-65e1-494169cb415d@deltatee.com> <1519945204.4592.45.camel@au1.ibm.com> <595acefb-18fc-e650-e172-bae271263c4c@deltatee.com> <1519946734.4592.48.camel@au1.ibm.com> <1520027052.4592.60.camel@kernel.crashing.org> From: Logan Gunthorpe Message-ID: Date: Fri, 2 Mar 2018 15:24:36 -0700 MIME-Version: 1.0 In-Reply-To: <1520027052.4592.60.camel@kernel.crashing.org> Content-Language: en-US Subject: Re: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Benjamin Herrenschmidt , Dan Williams Cc: Jens Axboe , linux-block@vger.kernel.org, Oliver OHalloran , linux-nvdimm , linux-rdma , linux-pci@vger.kernel.org, Linux Kernel Mailing List , linux-nvme@lists.infradead.org, Keith Busch , Alex Williamson , Jason Gunthorpe , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-ID: On 02/03/18 02:44 PM, Benjamin Herrenschmidt wrote: > Allright, so, I think I have a plan to fix this, but it will take a > little bit of time. > > Basically the idea is to have firmware pass to Linux a region that's > known to not have anything in it that it can use for the vmalloc space > rather than have linux arbitrarily cut the address space in half. > > I'm pretty sure I can always find large enough "holes" in the physical > address space that are outside of both RAM/OpenCAPI/Nvlink and > PCIe/MMIO space. If anything, unused chip IDs. But I don't want Linux > to have to know about the intimate HW details so I'll pass it from FW. > > It will take some time to adjust Linux and get updated FW around > though. > > Once that's done, I'll be able to have the linear mapping go through > the entire 52-bit space (minus that hole). Of course the hole need to > be large enough to hold a vmemmap for a 52-bit space, so that's about > 4TB. So I probably need a hole that's at least 8TB. > > As for the mapping attributes, it should be easy for my linear mapping > code to ensure anything that isn't actual RAM is mapped NC. Very cool. I'm glad to hear you found a way to fix this. Thanks, Logan _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: Benjamin Herrenschmidt , Dan Williams Cc: Jens Axboe , Keith Busch , Oliver OHalloran , Alex Williamson , linux-nvdimm , linux-rdma , linux-pci@vger.kernel.org, Linux Kernel Mailing List , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig References: <20180228234006.21093-1-logang@deltatee.com> <1519876489.4592.3.camel@kernel.crashing.org> <1519876569.4592.4.camel@au1.ibm.com> <1519936477.4592.23.camel@au1.ibm.com> <2079ba48-5ae5-5b44-cce1-8175712dd395@deltatee.com> <43ba615f-a6e1-9444-65e1-494169cb415d@deltatee.com> <1519945204.4592.45.camel@au1.ibm.com> <595acefb-18fc-e650-e172-bae271263c4c@deltatee.com> <1519946734.4592.48.camel@au1.ibm.com> <1520027052.4592.60.camel@kernel.crashing.org> From: Logan Gunthorpe Message-ID: Date: Fri, 2 Mar 2018 15:24:36 -0700 MIME-Version: 1.0 In-Reply-To: <1520027052.4592.60.camel@kernel.crashing.org> Content-Type: text/plain; charset=utf-8; format=flowed Subject: Re: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory List-ID: On 02/03/18 02:44 PM, Benjamin Herrenschmidt wrote: > Allright, so, I think I have a plan to fix this, but it will take a > little bit of time. > > Basically the idea is to have firmware pass to Linux a region that's > known to not have anything in it that it can use for the vmalloc space > rather than have linux arbitrarily cut the address space in half. > > I'm pretty sure I can always find large enough "holes" in the physical > address space that are outside of both RAM/OpenCAPI/Nvlink and > PCIe/MMIO space. If anything, unused chip IDs. But I don't want Linux > to have to know about the intimate HW details so I'll pass it from FW. > > It will take some time to adjust Linux and get updated FW around > though. > > Once that's done, I'll be able to have the linear mapping go through > the entire 52-bit space (minus that hole). Of course the hole need to > be large enough to hold a vmemmap for a 52-bit space, so that's about > 4TB. So I probably need a hole that's at least 8TB. > > As for the mapping attributes, it should be easy for my linear mapping > code to ensure anything that isn't actual RAM is mapped NC. Very cool. I'm glad to hear you found a way to fix this. Thanks, Logan From mboxrd@z Thu Jan 1 00:00:00 1970 From: Logan Gunthorpe Subject: Re: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory Date: Fri, 2 Mar 2018 15:24:36 -0700 Message-ID: References: <20180228234006.21093-1-logang@deltatee.com> <1519876489.4592.3.camel@kernel.crashing.org> <1519876569.4592.4.camel@au1.ibm.com> <1519936477.4592.23.camel@au1.ibm.com> <2079ba48-5ae5-5b44-cce1-8175712dd395@deltatee.com> <43ba615f-a6e1-9444-65e1-494169cb415d@deltatee.com> <1519945204.4592.45.camel@au1.ibm.com> <595acefb-18fc-e650-e172-bae271263c4c@deltatee.com> <1519946734.4592.48.camel@au1.ibm.com> <1520027052.4592.60.camel@kernel.crashing.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1520027052.4592.60.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@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: Benjamin Herrenschmidt , Dan Williams Cc: Jens Axboe , linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Oliver OHalloran , linux-nvdimm , linux-rdma , linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux Kernel Mailing List , linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Keith Busch , Alex Williamson , Jason Gunthorpe , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-Id: linux-rdma@vger.kernel.org On 02/03/18 02:44 PM, Benjamin Herrenschmidt wrote: > Allright, so, I think I have a plan to fix this, but it will take a > little bit of time. > > Basically the idea is to have firmware pass to Linux a region that's > known to not have anything in it that it can use for the vmalloc space > rather than have linux arbitrarily cut the address space in half. > > I'm pretty sure I can always find large enough "holes" in the physical > address space that are outside of both RAM/OpenCAPI/Nvlink and > PCIe/MMIO space. If anything, unused chip IDs. But I don't want Linux > to have to know about the intimate HW details so I'll pass it from FW. > > It will take some time to adjust Linux and get updated FW around > though. > > Once that's done, I'll be able to have the linear mapping go through > the entire 52-bit space (minus that hole). Of course the hole need to > be large enough to hold a vmemmap for a 52-bit space, so that's about > 4TB. So I probably need a hole that's at least 8TB. > > As for the mapping attributes, it should be easy for my linear mapping > code to ensure anything that isn't actual RAM is mapped NC. Very cool. I'm glad to hear you found a way to fix this. Thanks, Logan From mboxrd@z Thu Jan 1 00:00:00 1970 From: logang@deltatee.com (Logan Gunthorpe) Date: Fri, 2 Mar 2018 15:24:36 -0700 Subject: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory In-Reply-To: <1520027052.4592.60.camel@kernel.crashing.org> References: <20180228234006.21093-1-logang@deltatee.com> <1519876489.4592.3.camel@kernel.crashing.org> <1519876569.4592.4.camel@au1.ibm.com> <1519936477.4592.23.camel@au1.ibm.com> <2079ba48-5ae5-5b44-cce1-8175712dd395@deltatee.com> <43ba615f-a6e1-9444-65e1-494169cb415d@deltatee.com> <1519945204.4592.45.camel@au1.ibm.com> <595acefb-18fc-e650-e172-bae271263c4c@deltatee.com> <1519946734.4592.48.camel@au1.ibm.com> <1520027052.4592.60.camel@kernel.crashing.org> Message-ID: On 02/03/18 02:44 PM, Benjamin Herrenschmidt wrote: > Allright, so, I think I have a plan to fix this, but it will take a > little bit of time. > > Basically the idea is to have firmware pass to Linux a region that's > known to not have anything in it that it can use for the vmalloc space > rather than have linux arbitrarily cut the address space in half. > > I'm pretty sure I can always find large enough "holes" in the physical > address space that are outside of both RAM/OpenCAPI/Nvlink and > PCIe/MMIO space. If anything, unused chip IDs. But I don't want Linux > to have to know about the intimate HW details so I'll pass it from FW. > > It will take some time to adjust Linux and get updated FW around > though. > > Once that's done, I'll be able to have the linear mapping go through > the entire 52-bit space (minus that hole). Of course the hole need to > be large enough to hold a vmemmap for a 52-bit space, so that's about > 4TB. So I probably need a hole that's at least 8TB. > > As for the mapping attributes, it should be easy for my linear mapping > code to ensure anything that isn't actual RAM is mapped NC. Very cool. I'm glad to hear you found a way to fix this. Thanks, Logan