From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Date: Mon, 12 Jul 2004 19:54:56 +0000 Subject: Re: serious performance regression due to NX patch Message-Id: List-Id: References: <200407100528.i6A5SF8h020094@napali.hpl.hp.com> <20040711123803.GD21264@devserv.devel.redhat.com> <20040712182431.GB28281@infradead.org> <16626.57892.533203.683465@napali.hpl.hp.com> In-Reply-To: <16626.57892.533203.683465@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: davidm@hpl.hp.com Cc: Christoph Hellwig , Jakub Jelinek , suresh.b.siddha@intel.com, jun.nakajima@intel.com, Andrew Morton , Linus Torvalds , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Ulrich Drepper On Mon, 12 Jul 2004, David Mosberger wrote: > Ingo> is it an issue? Each new port will have PT_GNU_STACK, unless they base > Ingo> themselves on old compilers. > > PT_GNU_STACK is pure bloat on new architectures (and ia64). EF_IA_64_LINUX_EXECUTABLE_STACK is using elf_ex->e_flags. I did it the same way for x86 originally, but the tools people specifically rejected it as a hack. We dont control the ELF specification, but a new gcc section like PT_GNU_STACK is fair game. So it might be 'bloat' but it's clean and doesnt try to hijack. Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262106AbUGLT5t (ORCPT ); Mon, 12 Jul 2004 15:57:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262085AbUGLT5t (ORCPT ); Mon, 12 Jul 2004 15:57:49 -0400 Received: from mx1.redhat.com ([66.187.233.31]:38277 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262080AbUGLT5g (ORCPT ); Mon, 12 Jul 2004 15:57:36 -0400 Date: Mon, 12 Jul 2004 15:54:56 -0400 (EDT) From: Ingo Molnar X-X-Sender: mingo@devserv.devel.redhat.com To: davidm@hpl.hp.com cc: Christoph Hellwig , Jakub Jelinek , suresh.b.siddha@intel.com, jun.nakajima@intel.com, Andrew Morton , Linus Torvalds , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Ulrich Drepper Subject: Re: serious performance regression due to NX patch In-Reply-To: <16626.57892.533203.683465@napali.hpl.hp.com> Message-ID: References: <200407100528.i6A5SF8h020094@napali.hpl.hp.com> <20040711123803.GD21264@devserv.devel.redhat.com> <20040712182431.GB28281@infradead.org> <16626.57892.533203.683465@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 12 Jul 2004, David Mosberger wrote: > Ingo> is it an issue? Each new port will have PT_GNU_STACK, unless they base > Ingo> themselves on old compilers. > > PT_GNU_STACK is pure bloat on new architectures (and ia64). EF_IA_64_LINUX_EXECUTABLE_STACK is using elf_ex->e_flags. I did it the same way for x86 originally, but the tools people specifically rejected it as a hack. We dont control the ELF specification, but a new gcc section like PT_GNU_STACK is fair game. So it might be 'bloat' but it's clean and doesnt try to hijack. Ingo