From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f41.google.com (mail-qg0-f41.google.com [209.85.192.41]) by kanga.kvack.org (Postfix) with ESMTP id 380636B0032 for ; Wed, 22 Apr 2015 09:18:40 -0400 (EDT) Received: by qgej70 with SMTP id j70so83039756qge.2 for ; Wed, 22 Apr 2015 06:18:40 -0700 (PDT) Received: from e39.co.us.ibm.com (e39.co.us.ibm.com. [32.97.110.160]) by mx.google.com with ESMTPS id m42si4995384qkh.91.2015.04.22.06.18.38 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 22 Apr 2015 06:18:39 -0700 (PDT) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Apr 2015 07:18:38 -0600 Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 3901D1FF001F for ; Wed, 22 Apr 2015 07:09:45 -0600 (MDT) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t3MDIYmR41681044 for ; Wed, 22 Apr 2015 06:18:34 -0700 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t3MDIYwL007094 for ; Wed, 22 Apr 2015 07:18:34 -0600 Date: Wed, 22 Apr 2015 06:18:32 -0700 From: "Paul E. McKenney" Subject: Re: Interacting with coherent memory on external devices Message-ID: <20150422131832.GU5561@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20150421214445.GA29093@linux.vnet.ibm.com> <20150422000538.GB6046@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: 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, benh@kernel.crashing.org, aneesh.kumar@linux.vnet.ibm.com, Cameron Buschardt , Mark Hairgrove , Geoffrey Gerfin , John McKenna , akpm@linux-foundation.org On Tue, Apr 21, 2015 at 07:50:02PM -0500, Christoph Lameter wrote: > On Tue, 21 Apr 2015, Jerome Glisse wrote: [ . . . ] > > Paul is working on a platform that is more advance that the one HMM try > > to address and i believe the x86 platform will not have functionality > > such a CAPI, at least it is not part of any roadmap i know about for > > x86. > > We will be one of the first users of Paul's Platform. Please do not do > crazy stuff but give us a sane solution where we can control the > hardware. No strange VM hooks that automatically move stuff back and forth > please. If you do this we will have to disable them anyways because they > would interfere with our needs to have the code not be disturbed by random > OS noise. We need detailed control as to when and how we move data. I completely agree that some critically important use cases, such as yours, will absolutely require that the application explicitly choose memory placement and have the memory stay there. Requirement 2 was supposed to be getting at this by saying "explicitly or implicitly allocated", with the "explicitly" calling out your use case. How should I reword this to better bring this out? Thanx, Paul -- 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