From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (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 81F562130A511 for ; Mon, 12 Aug 2019 14:51:14 -0700 (PDT) Date: Mon, 12 Aug 2019 14:48:55 -0700 From: Ira Weiny Subject: Re: [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages() Message-ID: <20190812214854.GF20634@iweiny-DESK2.sc.intel.com> References: <20190809225833.6657-1-ira.weiny@intel.com> <20190809225833.6657-16-ira.weiny@intel.com> <20190812122814.GC24457@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190812122814.GC24457@ziepe.ca> 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: Jason Gunthorpe Cc: Michal Hocko , Theodore Ts'o , linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, John Hubbard , Dave Chinner , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Jan Kara , Andrew Morton , linux-ext4@vger.kernel.org List-ID: On Mon, Aug 12, 2019 at 09:28:14AM -0300, Jason Gunthorpe wrote: > On Fri, Aug 09, 2019 at 03:58:29PM -0700, ira.weiny@intel.com wrote: > > From: Ira Weiny > > > > The addition of FOLL_LONGTERM has taken on additional meaning for CMA > > pages. > > > > In addition subsystems such as RDMA require new information to be passed > > to the GUP interface to track file owning information. As such a simple > > FOLL_LONGTERM flag is no longer sufficient for these users to pin pages. > > > > Introduce a new GUP like call which takes the newly introduced vaddr_pin > > information. Failure to pass the vaddr_pin object back to a vaddr_put* > > call will result in a failure if pins were created on files during the > > pin operation. > > Is this a 'vaddr' in the traditional sense, ie does it work with > something returned by valloc? ...or malloc in user space, yes. I think the idea is that it is a user virtual address. > > Maybe another name would be better? Maybe, the name I had was way worse... So I'm not even going to admit to it... ;-) So I'm open to suggestions. Jan gave me this one, so I figured it was safer to suggest it... :-D > > I also wish GUP like functions took in a 'void __user *' instead of > the unsigned long to make this clear :\ Not a bad idea. But I only see a couple of call sites who actually use a 'void __user *' to pass into GUP... :-/ For RDMA the address is _never_ a 'void __user *' AFAICS. For the new API, it may be tractable to force users to cast to 'void __user *' but it is not going to provide any type safety. But it is easy to change in this series. What do others think? Ira > > Jason > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm