From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCHv1, RFC 0/8] Boot-time switching between 4- and 5-level paging Date: Fri, 26 May 2017 12:23:18 -0700 Message-ID: <40d58ba7-277c-6f4e-a4d7-15425d675dbf@intel.com> References: <20170525203334.867-1-kirill.shutemov@linux.intel.com> <20170526130057.t7zsynihkdtsepkf@node.shutemov.name> <83F4880B-5D1F-4576-A9B6-7DDF4173E2E5@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com ([134.134.136.24]:26915 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754322AbdEZTXe (ORCPT ); Fri, 26 May 2017 15:23:34 -0400 In-Reply-To: <83F4880B-5D1F-4576-A9B6-7DDF4173E2E5@zytor.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: hpa@zytor.com, Linus Torvalds , "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , Andrew Morton , the arch/x86 maintainers , Thomas Gleixner , Ingo Molnar , Andi Kleen , Andy Lutomirski , "linux-arch@vger.kernel.org" , linux-mm , Linux Kernel Mailing List On 05/26/2017 11:24 AM, hpa@zytor.com wrote: > The only case where that even has any utility is for an application > to want more than 128 TiB address space on a machine with no more > than 64 TiB of RAM. It is kind of a narrow use case, I think. Doesn't more address space increase the effectiveness of ASLR? I thought KASLR, especially, was limited in its effectiveness because of a lack of address space.