From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hqemgate16.nvidia.com (hqemgate16.nvidia.com [216.228.121.65]) (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 B96F020212CA1 for ; Wed, 21 Aug 2019 11:46:36 -0700 (PDT) Subject: Re: [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ; -) References: <20190814101714.GA26273@quack2.suse.cz> <20190814180848.GB31490@iweiny-DESK2.sc.intel.com> <20190815130558.GF14313@quack2.suse.cz> <20190816190528.GB371@iweiny-DESK2.sc.intel.com> <20190817022603.GW6129@dread.disaster.area> <20190819063412.GA20455@quack2.suse.cz> <20190819092409.GM7777@dread.disaster.area> <20190820012021.GQ7777@dread.disaster.area> <84318b51-bd07-1d9b-d842-e65cac2ff484@nvidia.com> <20190820033608.GB1119@dread.disaster.area> From: John Hubbard Message-ID: <29c89d84-d847-0221-70a7-9e5a3d472cda@nvidia.com> Date: Wed, 21 Aug 2019 11:43:30 -0700 MIME-Version: 1.0 In-Reply-To: <20190820033608.GB1119@dread.disaster.area> Content-Language: en-US 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: Dave Chinner Cc: Michal Hocko , Jan Kara , linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-xfs@vger.kernel.org, Jason Gunthorpe , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Theodore Ts'o , Andrew Morton , linux-ext4@vger.kernel.org List-ID: On 8/19/19 8:36 PM, Dave Chinner wrote: > On Mon, Aug 19, 2019 at 08:09:33PM -0700, John Hubbard wrote: >> On 8/19/19 6:20 PM, Dave Chinner wrote: >>> On Mon, Aug 19, 2019 at 05:05:53PM -0700, John Hubbard wrote: >>>> On 8/19/19 2:24 AM, Dave Chinner wrote: >>>>> On Mon, Aug 19, 2019 at 08:34:12AM +0200, Jan Kara wrote: >>>>>> On Sat 17-08-19 12:26:03, Dave Chinner wrote: >>>>>>> On Fri, Aug 16, 2019 at 12:05:28PM -0700, Ira Weiny wrote: >>>>>>>> On Thu, Aug 15, 2019 at 03:05:58PM +0200, Jan Kara wrote: >>>>>>>>> On Wed 14-08-19 11:08:49, Ira Weiny wrote: >>>>>>>>>> On Wed, Aug 14, 2019 at 12:17:14PM +0200, Jan Kara wrote: >>>> ... > AFAIA, there is no struct file here - the memory that has been pinned > is just something mapped into the application's address space. > > It seems to me that the socket here is equivalent of the RDMA handle > that that owns the hardware that pins the pages. Again, that RDMA > handle is not aware of waht the mapping represents, hence need to > hold a layout lease if it's a file mapping. > > SO from the filesystem persepctive, there's no difference between > XDP or RDMA - if it's a FSDAX mapping then it is DMAing directly > into the filesystem's backing store and that will require use of > layout leases to perform safely. > OK, got it! Makes perfect sense. thanks, -- John Hubbard NVIDIA _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm