From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory Date: Wed, 19 Apr 2017 14:48:08 -0600 Message-ID: <20170419204808.GA15716@obsidianresearch.com> References: <20170418210339.GA24257@obsidianresearch.com> <1492564806.25766.124.camel@kernel.crashing.org> <20170419155557.GA8497@obsidianresearch.com> <4899b011-bdfb-18d8-ef00-33a1516216a6@deltatee.com> <20170419171451.GA10020@obsidianresearch.com> <20170419183247.GA13716@obsidianresearch.com> <21e8099a-d19d-7df0-682d-627d8b81dfde@deltatee.com> <20170419193154.GA14340@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: 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 Cc: Jens Axboe , "James E.J. Bottomley" , "Martin K. Petersen" , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Benjamin Herrenschmidt , Steve Wise , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Keith Busch , Jerome Glisse , Bjorn Helgaas , linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm , Max Gurtovoy , linux-scsi , Christoph Hellwig List-Id: linux-rdma@vger.kernel.org On Wed, Apr 19, 2017 at 01:41:49PM -0600, Logan Gunthorpe wrote: > > But.. it could point to a GPU and the GPU struct device could have a > > proxy dma_ops like Dan pointed out. > > Seems a bit awkward to me that in order for the intended use case, you > have to proxy the dma_ops. I'd probably still suggest throwing a couple > ops for things like this in the dev_pagemap. Another option is adding a new 'struct completer_dma_ops *' to struct device for this use case. Seems like a waste to expand dev_pagemap when we only need a unique value per struct device? Jason