From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id 0658C6B003D for ; Fri, 27 Jun 2014 13:43:08 -0400 (EDT) Received: by mail-pd0-f177.google.com with SMTP id y10so4644908pdj.22 for ; Fri, 27 Jun 2014 10:43:08 -0700 (PDT) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id fl5si14657737pbb.220.2014.06.27.10.43.07 for ; Fri, 27 Jun 2014 10:43:08 -0700 (PDT) Message-ID: <53ADACF7.7080203@intel.com> Date: Fri, 27 Jun 2014 10:42:15 -0700 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [PATCH v6 02/10] x86, mpx: add MPX specific mmap interface References: <1403084656-27284-1-git-send-email-qiaowei.ren@intel.com> <53A884B2.5070702@mit.edu> <53A88806.1060908@intel.com> <53A88DE4.8050107@intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE016AF41C@shsmsx102.ccr.corp.intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE016B26AB@shsmsx102.ccr.corp.intel.com> <53AB42E1.4090102@intel.com> <53ACA5B3.3010702@intel.com> <53ACB8A7.9050002@intel.com> <53ADAB39.6030403@intel.com> In-Reply-To: <53ADAB39.6030403@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: "Ren, Qiaowei" , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , X86 ML , "linux-kernel@vger.kernel.org" , Linux MM On 06/27/2014 10:34 AM, Dave Hansen wrote: > I'm claiming that we need COW behavior for the bounds tables, at least > by default. If userspace knows enough about the ways that it is using > the tables and knows how to share them, let it go to town. The kernel > will permit this kind of usage model, but we simply won't be helping > with the management of the tables when userspace creates them. Actually, this is another reason we need to mark VMAs as being MPX-related explicitly instead of inferring it from the tables. If userspace does something really specialized like this, the kernel does not want to confuse these VMAs the ones it created. -- 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