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Date:   Mon, 12 Aug 2019 09:28:14 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     ira.weiny@intel.com
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Theodore Ts'o <tytso@mit.edu>,
        John Hubbard <jhubbard@nvidia.com>,
        Michal Hocko <mhocko@suse.com>,
        Dave Chinner <david@fromorbit.com>, linux-xfs@vger.kernel.org,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org,
        linux-ext4@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages()
Message-ID: <20190812122814.GC24457@ziepe.ca>
References: <20190809225833.6657-1-ira.weiny@intel.com>
 <20190809225833.6657-16-ira.weiny@intel.com>
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On Fri, Aug 09, 2019 at 03:58:29PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> 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?

Maybe another name would be better?

I also wish GUP like functions took in a 'void __user *' instead of
the unsigned long to make this clear :\

Jason