Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756808AbbDXPwt (ORCPT <rfc822;w@1wt.eu>);
	Fri, 24 Apr 2015 11:52:49 -0400
Received: from resqmta-ch2-07v.sys.comcast.net ([69.252.207.39]:45647 "EHLO
	resqmta-ch2-07v.sys.comcast.net" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1030831AbbDXPwG (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 24 Apr 2015 11:52:06 -0400
Date: Fri, 24 Apr 2015 10:52:03 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
X-X-Sender: cl@gentwo.org
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
cc: Austin S Hemmelgarn <ahferroin7@gmail.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Jerome Glisse <j.glisse@gmail.com>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, jglisse@redhat.com, mgorman@suse.de,
        aarcange@redhat.com, riel@redhat.com, airlied@redhat.com,
        aneesh.kumar@linux.vnet.ibm.com,
        Cameron Buschardt <cabuschardt@nvidia.com>,
        Mark Hairgrove <mhairgrove@nvidia.com>,
        Geoffrey Gerfin <ggerfin@nvidia.com>,
        John McKenna <jmckenna@nvidia.com>, akpm@linux-foundation.org
Subject: Re: Interacting with coherent memory on external devices
In-Reply-To: <20150424145738.GZ5561@linux.vnet.ibm.com>
Message-ID: <alpine.DEB.2.11.1504241051090.9889@gentwo.org>
References: <alpine.DEB.2.11.1504211839120.6294@gentwo.org> <20150422000538.GB6046@gmail.com> <alpine.DEB.2.11.1504211942040.6294@gentwo.org> <20150422131832.GU5561@linux.vnet.ibm.com> <alpine.DEB.2.11.1504221105130.24979@gentwo.org>
 <1429756200.4915.19.camel@kernel.crashing.org> <alpine.DEB.2.11.1504230921020.32297@gentwo.org> <55390EE1.8020304@gmail.com> <20150423193339.GR5561@linux.vnet.ibm.com> <alpine.DEB.2.11.1504240909350.7582@gentwo.org>
 <20150424145738.GZ5561@linux.vnet.ibm.com>
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 822
Lines: 19

On Fri, 24 Apr 2015, Paul E. McKenney wrote:

> > DAX is a mechanism to access memory not managed by the kernel and is the
> > successor to XIP. It just happens to be needed for persistent memory.
> > Fundamentally any driver can provide an MMAPPed interface to allow access
> > to a devices memory.
>
> I will take another look, but others in this thread have called out
> difficulties with DAX's filesystem nature.

Right so you do not need the filesystem structure. Just simply writing a
device driver that mmaps data as needed from the coprocessor will also do
the trick.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/