From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com (mail-ig0-f169.google.com [209.85.213.169]) by kanga.kvack.org (Postfix) with ESMTP id 37A2C6B0032 for ; Fri, 24 Apr 2015 11:52:05 -0400 (EDT) Received: by igbyr2 with SMTP id yr2so18351911igb.0 for ; Fri, 24 Apr 2015 08:52:05 -0700 (PDT) Received: from resqmta-ch2-07v.sys.comcast.net (resqmta-ch2-07v.sys.comcast.net. [2001:558:fe21:29:69:252:207:39]) by mx.google.com with ESMTPS id o19si2343921igs.5.2015.04.24.08.52.04 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 24 Apr 2015 08:52:04 -0700 (PDT) Date: Fri, 24 Apr 2015 10:52:03 -0500 (CDT) From: Christoph Lameter Subject: Re: Interacting with coherent memory on external devices In-Reply-To: <20150424145738.GZ5561@linux.vnet.ibm.com> Message-ID: References: <20150422000538.GB6046@gmail.com> <20150422131832.GU5561@linux.vnet.ibm.com> <1429756200.4915.19.camel@kernel.crashing.org> <55390EE1.8020304@gmail.com> <20150423193339.GR5561@linux.vnet.ibm.com> <20150424145738.GZ5561@linux.vnet.ibm.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: "Paul E. McKenney" Cc: Austin S Hemmelgarn , Benjamin Herrenschmidt , Jerome Glisse , 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 , Mark Hairgrove , Geoffrey Gerfin , John McKenna , akpm@linux-foundation.org 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org