From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752011AbdI1IaA (ORCPT ); Thu, 28 Sep 2017 04:30:00 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:37638 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751592AbdI1I37 (ORCPT ); Thu, 28 Sep 2017 04:29:59 -0400 X-Google-Smtp-Source: AOwi7QAzOigMKFFCr7xBwoZ2Pbdt0on6LR6MQ6xgP7A3ckQLg3CPgASb8TDTuN2U5+O+s9MqIPnypg== Date: Thu, 28 Sep 2017 10:29:55 +0200 From: Ingo Molnar To: "Kirill A. Shutemov" Cc: Ingo Molnar , Linus Torvalds , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , Andy Lutomirski , Cyrill Gorcunov , Borislav Petkov , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv7 11/19] x86/mm: Make STACK_TOP_MAX dynamic Message-ID: <20170928082955.n7t4wlz7olsgwkfn@gmail.com> References: <20170918105553.27914-1-kirill.shutemov@linux.intel.com> <20170918105553.27914-12-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170918105553.27914-12-kirill.shutemov@linux.intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Kirill A. Shutemov wrote: > For boot-time switching between paging modes, we need to be able to > change STACK_TOP_MAX at runtime. > > The change is trivial and it doesn't affect kernel image size. > > Signed-off-by: Kirill A. Shutemov > --- > arch/x86/include/asm/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h > index 3fa26a61eabc..fa9300ccce1b 100644 > --- a/arch/x86/include/asm/processor.h > +++ b/arch/x86/include/asm/processor.h > @@ -871,7 +871,7 @@ static inline void spin_lock_prefetch(const void *x) > IA32_PAGE_OFFSET : TASK_SIZE_MAX) > > #define STACK_TOP TASK_SIZE_LOW > -#define STACK_TOP_MAX TASK_SIZE_MAX > +#define STACK_TOP_MAX (pgtable_l5_enabled ? TASK_SIZE_MAX : DEFAULT_MAP_WINDOW) While it's only used once in fs/exec.c, why doesn't it affect kernel image size? Thanks, Ingo