From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-x22e.google.com (mail-it0-x22e.google.com [IPv6:2607:f8b0:4001:c0b::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C8CB5210DA7AF for ; Thu, 30 Aug 2018 12:11:22 -0700 (PDT) Received: by mail-it0-x22e.google.com with SMTP id p129-v6so4158244ite.3 for ; Thu, 30 Aug 2018 12:11:22 -0700 (PDT) Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests References: <20180830185352.3369-1-logang@deltatee.com> <20180830185352.3369-8-logang@deltatee.com> From: Jens Axboe Message-ID: Date: Thu, 30 Aug 2018 13:11:18 -0600 MIME-Version: 1.0 In-Reply-To: <20180830185352.3369-8-logang@deltatee.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Logan Gunthorpe , 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: =?UTF-8?Q?Christian_K=c3=b6nig?= , Benjamin Herrenschmidt , Alex Williamson , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-ID: On 8/30/18 12:53 PM, Logan Gunthorpe wrote: > QUEUE_FLAG_PCI_P2P is introduced meaning a driver's request queue > supports targeting P2P memory. > > When a request is submitted we check if PCI P2PDMA memory is assigned > to the first page in the bio. If it is, we ensure the queue it's > submitted to supports it, and enforce REQ_NOMERGE. I think this belongs in the caller - both the validity check, and passing in NOMERGE for this type of request. I don't want to impose this overhead on everything, for a pretty niche case. -- Jens Axboe _______________________________________________ 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: Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests To: Logan Gunthorpe , 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 , Keith Busch , Sagi Grimberg , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , Dan Williams , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Benjamin Herrenschmidt , Alex Williamson , =?UTF-8?Q?Christian_K=c3=b6nig?= References: <20180830185352.3369-1-logang@deltatee.com> <20180830185352.3369-8-logang@deltatee.com> From: Jens Axboe Message-ID: Date: Thu, 30 Aug 2018 13:11:18 -0600 MIME-Version: 1.0 In-Reply-To: <20180830185352.3369-8-logang@deltatee.com> Content-Type: text/plain; charset=utf-8 List-ID: On 8/30/18 12:53 PM, Logan Gunthorpe wrote: > QUEUE_FLAG_PCI_P2P is introduced meaning a driver's request queue > supports targeting P2P memory. > > When a request is submitted we check if PCI P2PDMA memory is assigned > to the first page in the bio. If it is, we ensure the queue it's > submitted to supports it, and enforce REQ_NOMERGE. I think this belongs in the caller - both the validity check, and passing in NOMERGE for this type of request. I don't want to impose this overhead on everything, for a pretty niche case. -- Jens Axboe From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests Date: Thu, 30 Aug 2018 13:11:18 -0600 Message-ID: References: <20180830185352.3369-1-logang@deltatee.com> <20180830185352.3369-8-logang@deltatee.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180830185352.3369-8-logang-OTvnGxWRz7hWk0Htik3J/w@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: Logan Gunthorpe , 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: =?UTF-8?Q?Christian_K=c3=b6nig?= , Benjamin Herrenschmidt , Alex Williamson , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-Id: linux-rdma@vger.kernel.org On 8/30/18 12:53 PM, Logan Gunthorpe wrote: > QUEUE_FLAG_PCI_P2P is introduced meaning a driver's request queue > supports targeting P2P memory. > > When a request is submitted we check if PCI P2PDMA memory is assigned > to the first page in the bio. If it is, we ensure the queue it's > submitted to supports it, and enforce REQ_NOMERGE. I think this belongs in the caller - both the validity check, and passing in NOMERGE for this type of request. I don't want to impose this overhead on everything, for a pretty niche case. -- Jens Axboe From mboxrd@z Thu Jan 1 00:00:00 1970 From: axboe@kernel.dk (Jens Axboe) Date: Thu, 30 Aug 2018 13:11:18 -0600 Subject: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests In-Reply-To: <20180830185352.3369-8-logang@deltatee.com> References: <20180830185352.3369-1-logang@deltatee.com> <20180830185352.3369-8-logang@deltatee.com> Message-ID: On 8/30/18 12:53 PM, Logan Gunthorpe wrote: > QUEUE_FLAG_PCI_P2P is introduced meaning a driver's request queue > supports targeting P2P memory. > > When a request is submitted we check if PCI P2PDMA memory is assigned > to the first page in the bio. If it is, we ensure the queue it's > submitted to supports it, and enforce REQ_NOMERGE. I think this belongs in the caller - both the validity check, and passing in NOMERGE for this type of request. I don't want to impose this overhead on everything, for a pretty niche case. -- Jens Axboe