From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vn0-f41.google.com (mail-vn0-f41.google.com [209.85.216.41]) by kanga.kvack.org (Postfix) with ESMTP id 0A5D96B0038 for ; Mon, 27 Apr 2015 15:35:29 -0400 (EDT) Received: by vnbg1 with SMTP id g1so13357647vnb.2 for ; Mon, 27 Apr 2015 12:35:27 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id az11si31301849vdd.56.2015.04.27.12.35.26 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Apr 2015 12:35:27 -0700 (PDT) Message-ID: <553E8F75.5060502@redhat.com> Date: Mon, 27 Apr 2015 15:35:17 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: Interacting with coherent memory on external devices References: <20150424171957.GE3840@gmail.com> <20150424192859.GF3840@gmail.com> <20150425114633.GI5561@linux.vnet.ibm.com> <20150427154728.GA26980@gmail.com> <20150427164325.GB26980@gmail.com> <20150427172143.GC26980@gmail.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter , Jerome Glisse Cc: "Paul E. McKenney" , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, mgorman@suse.de, aarcange@redhat.com, airlied@redhat.com, aneesh.kumar@linux.vnet.ibm.com, Cameron Buschardt , Mark Hairgrove , Geoffrey Gerfin , John McKenna , akpm@linux-foundation.org On 04/27/2015 03:26 PM, Christoph Lameter wrote: > DAX is about directly accessing memory. It is made for the purpose of > serving as a block device for a filesystem right now but it can easily be > used as a way to map any external memory into a processes space using the > abstraction of a block device. But then you can do that with any device > driver using VM_PFNMAP or VM_MIXEDMAP. Maybe we better use that term > instead. Guess I have repeated myself 6 times or so now? I am stopping > with this one. Yeah, please stop. If after 6 times you have still not grasped that having the application manage which memory goes onto the device and which goes in RAM is the exact opposite of the use model that Paul and Jerome are trying to enable (transparent moving around of memory, by eg. GPU calculation libraries), you are clearly not paying enough attention. -- All rights reversed -- 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